Industrial Safty

IG/02 For restricted Circulation Only

INDUSTRIAL SAFETY

Power Management Institute Noida

CONTENTS S. No.

Subject

Page Nos.

1.

Accident – Causes and Factors

1

2.

Cost of Accident

8

3.

Accident Prevention

11

4.

Accident Investigation & Records

16

5.

Techniques of Discovering Hazards

23

6.

Investigation of Accidents

43

7.

Procedure for Reporting of Accidents/ Dangerous Occurrences

52

8.

Guidelines on Constitution of Enquiry Committee

63

9.

Safety Policy

69

10.

Industrial Hazards

74

11.

Protective Clothing & Equipment

82

12.

Safety in Movement of Men & Material

88

13.

Safety in Construction

100

14.

Safe Working Practices in Thermal Power Station

108

15.

Permit to Work System

115

16.

An Executive’s Role in Safety

119

17.

Factories Act - 1948

124

18.

Indian Electricity Act & Rules

132

19.

Gas Cylinder Rules - 1981

138

20.

Legal Aspects of Safety Under the Acts

152

21.

Health Hazards of Hazardous Chemicals

161

22.

Indian Boiler Act – 1923

171

23.

Inspection of Steam Boilers

185

24.

House Keeping

192

25.

Fire Safety

197

26.

Portable Fire Extinguishers

204

27.

Fire Prevention and Protection System for Thermal Power Station

234

28.

Introduction to First Aid

243

29.

First Aid to the injured

250

1. AccidentsAccidents- Causes & Factors INTRODUCTION

The ordinary meaning of the word “ Accident ” as derived from lexicons is an unforeseen

of an unexpected event’. This definition covers a wide range of

phenomena including even natural catastrophes and cannot, therefore, subserve the purpose of a scientific investigation. The term accident ‘when used in industry’, while in essence retaining this popular connota tion, refers to a district class of the phenomena. The American ‘National Safety Council’ has defined accident as “ that occurrence in a sequence of events which usually produces unintended injury, death or the property damage. Heinrich’ has, however, defined accident as “an unplanned and uncontrolled event in which the action or reaction on an object, substance, person or radiation result in personal injury.” Basically accidents constitute a behavioral problem signifying a disintegration in the equilibrium of the individual in relation to the work situation. The forces that make for the disequilibrium are mainly drawn from the stress of the work situation and the psycho- social character of the individual involved. As soon as this filed is distributed due to the displacement of the relatively specific situation or the appearance of new one the equilibrium is upset, causing an interruption or disorganization in performance. By and large, therefore, accidents are defined as “unforeseen, sudden, unintended or unconscious deviations in work activity tending to end to an injury”.

CAUSES OF ACCIDENTS The causes may be human or mechanical failures .The two broad sources of the accidents may be classified into:

© PMI, NTPC

1

i)

Unsafe conditions, and

ii)

Unsafe acts

An ‘unsafe condition’ may refer to the condition of the floor, of the ladder, of a machine, of a stairway, of a tool, of a conveyor belt of anything else of physical, environmental or mechanical character which could lead to an accident. An ‘unsafe act’ is something somebody does which may culminate in an accident. The word “may” is used because it is not necessary that it should always lead to an accident, but we can be sure that if such acts are persisted they will result in avoidable injuries. It is a matter of considerable debate whether out of ‘unsafe’ condition ’and ‘unsafe act’ which is more important. The question is a difficult one. Both are important. The significance of separating causes into two kinds is that it draws attention to fact that the attack strategy should be two- pronged. We must prevent unsafe acts, not one or the other. What then is the relationship between the two? The cause of nearly all accidents has relations to an unsafe condition. This unsafe condition contains the POTENTIAL to injure someone (e.g., an unguarded press, an unfenced floor opening. a piece of wood with a nail on the floor, and so on.) It is the unsafe act that leads to an accident. We may call it the “triggering” cause because it releases the danger potential of unsafe condition somewhat as the pressing of trigger of gun release the unsafe potential of the loaded bullet.

How do we tackle the problem? --

The first attack has to be on the unsafe condition. Because it alone is completely controllable

© PMI, NTPC

2

--

The next important attack has to be on ‘unsafe acts ‘of the people. To place this line to attack second does not mean that it is relatively unimportant but only that it is harder to control less immediate in effect. Even through, in the short run. More certain and quicker results can be obtained by rectifying unsafe conditions in the long run the only way to make places accident free is to teach the people to work safely and to see they practice it.

FACTORS CONTRIBUTING TO ACCIDENTS These are classified into four on the basis of the area of their origin, the person or the environment and according to the basis of proximity to accident event: --

Mechanical

--

Environment

--

Human

--

Human mechanical causes.

Mechanical causes These relates to the defects and inadequate safeguards o f machinery to unsafe conditions of equipment --

Inadequately guarded,

--

Unguarded

--

Unsafe design or construction,

--

Hazardous arrangement (pilling, Overloading, etc.)

© PMI, NTPC

3

Environmental Causes The environmental causes of accidents refer to inadequate physical and atmospheric conditions of work. They are distinguished from mechanical causes by the fact they do not cause the accident directly, but indirectly contribute to its occurrence, by virtue of their adverse effects upon the individual.

The

environmental causes are also, sometimes, designated as ‘External’ to the individual and ‘general’ where all the workers are affected by them. Some of the important environmental factor which contributes to accident causation are: --

Elimination

--

Ventilation

--

Temperature

--

Speed of work

---

Hours of work

--

Spread over to work period

--

Workload

Human Causes Human causes constitute by far the most important category to accident causes. Accidents due to human failure a preponderate over other of accidents. The various factors that constitute the human causes may be grouped as under: Individual Factors

Psychological Factors

a)

Age

a)

Attitude towards job

b)

Marriage

b)

Interest and Difficulties

© PMI, NTPC

4

c)

Education

c)

Machine habits

d)

Health

d)

Attention

e)

Length of service

e)

Fatigue

f)

Work performance

Personality Factors

Sociological Factors

a)

Intellectual level

a)

Size of family

b)

Emotional maturity

b)

Number of dependents

c)

Adjustment

c)

Financial position

d)

Anxiety level

d)

Social Status

e)

Interpersonal relations

f)

Home environment

Accidents have many ways of attending consummation. An accident may injure the workman or damage the machine or tools or injure a person other then one involved in the accident or may not attain consummation at all. Suppose a weaver is performing the operation of shutting on his loom and the shuttle freque ncy slips from his hand. Here, the fact of the shuttle slipping form the hand constitutes the accident, and the events that occur after that represent the effects of the accident. Accidents and injuries, therefore, represent two distinct classes of phenomena of different psychological importance. The antecedent circumstances in the causation of an injury are easily observable, but the predisposing causes of an accident often lie hidden in the inner strata of the organism of the individual, his history and the social environment factors of the work situation.

© PMI, NTPC

5

CLASSIFICATION OF ACCIDENTS Influencing Elements An accident situation comprises three elements: --

Work Deviation

--

Its causes and,

--

Its effects.

Accidents may, therefore, be classified on the basis of these three elements. According to the nature of the work deviation, accidents are classified as: --

Striking against

--

Struck by

--

Caught in or between

--

Fall on same level

--

Overexertion

--

Inhalation or absorption

-

Contract with electrically charged objects.

Striking Against This class refers to such incidents as the workers dashing against machines or other objects or colliding with a fellow worker or some other or object, Such accidents constitute an important class for psychological study due to the predominantly human character of their causation.

© PMI, NTPC

6

Struck By These accidents are caused due to machine parts of broken belts or other falling, flying, sliding or moving objects striking of rubbing the body of the worker. Such accidents are generally due to defective equipment or unsafe working premises.

Caught in or between These consist of accidents resulting in either fingers being caught in between the gears or in between the pinion wheels or moving rollers or the hand getting entangled in the meshes of belt & pulleys. Other parts of the body may as well get similarly involved.

Falls, on same level Accidents of this type are a common experience of everyday life. While falls refer to a complete collapse of the individual’s musculature on the ground, slips signify only a temporary disturbance in muscular balance.

Exposure These are categories of infrequent occurrences. They are exemplified by such events as heat, exhaustion, Poisoning, Drowning and electrocution. Another classification on the basis of the severity of injury and consequent incapability for the work is commonly followed in accident analysis. Accordning to this classification. accidents may be divided into five categories: i)

Fatal

ii)

Serious

iii)

Minor

iv)

Trivial

v)

No injury accidents.

© PMI, NTPC

7

2. Cost Of Accidents INTRODUCTION

Often the extent of the cost of accident is not evident and hence not appreciated. Usually, only “direct costs which represent compensation and medical expenses to be borne by the management are taken into consideration when computing costs due to accidents. The hidden or ‘indirect costs’ to the management, the injured and society at large ignored every often.

COST OF THE INJURED The injured workers themselves are the very heavy losers. Their actual losses in money may not be so great as employer’s but he can ill –afford to withstand his share of financial burden. Where he is not covered by any benefit schemes of the management or any insurance, he will have to bear himself the loss of wages, the cost of medical expenses and the loss due to the any permanent disablement. Even when there are insurance of benefit scheme, the compensation and medical benefits are rarely adequate. Further no costing can be done to compensate for the suffering, pain, worry and effects due to incapacitation.

COST OF MANAGEMEN According to detailed study carried out by Heinrich the indirect costs which present all the incidental costs due to an accent except those relating to medical expenses and compensation, work out on an average to about four time the direct costs. Some studies report indirect costs to be even six times the direct costs. While these ratios indicate the average pattern, individual accidents could

© PMI, NTPC

8

be very costly particularly when the accidents are serious or result in heavy damage to equipment.

Direct Costs The direct costs of accidents comprise of (a) the compensation paid to the injured person; and (b) medical expenses on his treatment since both these are generally covered under insurance, the cost of accident on these accounts are also commonly as Insured Cost.

Indirect Costs The following items contribute towards the indirect of uninsured costs of accidents and can be calculated in terms of money unlike the other less tangible losses such as the effect of accidents on morale etc: ---

Lost time of injured employees: These are the wages paid for the time lost by the injured worker other than those paid under the workman’s compensation law.

---

Lost time of other employees: After an accident all employees of the section stop

to watch, assist or talk about it. Some time is also lost as

the equipment damages in accident is required or the output or aid of the injured person is required. ---

Lost time of Foreman, Supervisors or other executives: Time spent on activities such as investigating the accident, preparing reports, settling claims arising from it, selecting training or booking in new worker etc.

---

Cost of time spent by the first aid attendant and hospital staff of factory.

---

Cost of damage to material or equipment. This should also include the cost incurred in back in order the material or equipment which may be thrown into a state of disorder.

© PMI, NTPC

9

---

Incidental cost due to interference with production like loss of profit on contracts cancelled or orders lost.

---

Costs under employee welfare and benefit systems: These will be other than those paid as compensation.

---

Cost due to continuance of wages to injured persons in full: The output of injured worker is below normal for some period after he rejoins work.

---

Cost due to loss of profit on the injured worker‘s productivity and on idle machines.

---

Over head cost over injured worker: These are expenses for the light, heat, rent and other items with continue over while the injured worker is away from work.

COST OF SOCIETY Industrial accidents place a heavy burden on Society. It is ultimately the Society suffers all losses. For example, taking economical considerations alone, the financial losses of direct and indirect costs by the management will have to be met consumers in terms of increased cost of products. Further, it is society, which again, ultimately bears the financial burden of maintenance of all the disabled employees and their dependents. Looking at it from this board perspective, every citizen bears a proportion of the cost of accidents and knowing heavy costs, every effort should be made prevent accidents.

© PMI, NTPC

10

3. Accident Prevention INTRODUCTION

“An injury prevented is a benefaction, an injury compensated, an apology “ Industrial accident prevention has come of age. The long struggle for its recognition, for supporting interest and effective action, waged over a period of years by Government, Industry, Labour and other organizations has borne fruits. The need and value of Accident Prevention has not been well established and it is realised that emphasis should be placed on the practical methods of accomplishment.

Accident Prevention Accident prevention is both Science and Art. It represents, above all other things, “ Control” Control of man performance, Machine performance and physical environment The word control is used advisely because it connotes prevention as well as correction of unsafe conditions and circumstances. It is a vital factor in every industrial enterprise, one which, if ignored or practiced unskillfully leads to needless human suffering and business bankruptcy.

Implication The effect of accidents, besides the loss of life, property and money, is to restrict seriously both employment and production of goods and sevices on which the welfare of a nation depends. This prevention brings about spectacular achievements in the saving of life and limb, compensation, continuity of service, increased production, decreased labor turn-over and improved labour – management relations.

© PMI, NTPC

11

CONTROLING ACCOUNTS Where as three ‘Es’ of Safety representing engineering, education and enforcement are applied in the field of Industrial Safety, it seems much easier to comprehended the fundamentals of Accident Prevention if the

preventive

procedures are grouped in four general classifications which are a little more self–descriptive and which fit into the problem a little more closely than do three ‘Es’ These four classification may be : --

Discover causes

--

Control environment causes

--

Control behaviorist causes

--

Supplementary activities

Discovering Accident Causes Before any steps can be taken, it essential to find out: --

The causes of pervious accidents, and

---

The existing of hazards that will cause accidents unless corrected

These activities are necessary not only before starting the actual procedure for accident prevention but also afterwards, for they must given continuous never – ending attention. Otherwise the real effort of accident prevention will get out of hand.

Controlling Environmental Causes In this connection, it should be remembered that: ---

All the environment causes have something to do with machinery and equipment -with things that one can see or feel.

© PMI, NTPC

12

---

The Control procedures have relationship with engineering or with application of engineering principles.

In some respects the control of environment causes (or hazards) is the most essential factor in any accident prevention programme, since it proves to the workers that management is sincere in its desire to prevent accidents and is willing to do its part. In addition if there are two or more different ways to prevent certain types to accidents, this is preferable. For example. if there is hole in the floor and if any danger of workers falling it and bearing injured, it is much wiser and cheaper in long run to eliminate and fill that hole than to place a guard rail around it or to try teach workers to stay away. Trying to teach men to avoid a hazard is a never ending job requiring constant supervision and in some cases discipline, but the elimination of a hazard is an immediate and permanent cure.

Controlling Behavioristic Causes These can be controlled through the application of: --

Job analysis

--

Job training

--

Supervision

--

Discipline

---

Personal Work

--

Physical examination

--

Proper placement of workers

© PMI, NTPC

13

In general, it is much more difficult to control behavioristic causes than it is to control environmental causes. Unlike environment, human behavior is without substance, It can neither be seen or felt. It is the result of such complicated factors as heredity, emotion, diet and habits etc, therefore; it is not surprising that the method of control are somewhat complicated. They are exact sciences as are various fundamentals of engineering such as mathematics, physics and chemistry. For example, a wrong attitude is an important behavioristic cause that is more closely induced by worry. Many workers worry about current financial problem or about the possibility of poverty in old age or the expense on medical care. In many organizations personal activities have been instituted, such as pension plans, group health and accident insurance, and employees ‘credit unions, which have helped to relieve thousands of workers from some of their worries and problems, and thus helped in improving the company’s accident record.

Supplementary Activities These may be classified as under: --

Posters

--

Booklets and other literature

--

Movies

--

Films strips

--

Contests

--

Meetings

--

Committees

--

Suggestion System

© PMI, NTPC

14

--

Employee Magazines / Bulletins

--

Safety Handbooks.

These activities are of secondary importance when compared to others as they do not aim directly at the discovery and elimination of accident causes, but they are valuable in arising and maintaining interest in safety. It should be pointed out, however, that is not advisable to undertake all of these supplementary activities simultaneously. No attempt can be made to suggest their relative importance, for this varies in different establishments, depending upon such factors as existing conditions, personalities of executives, and needs of the moment.

© PMI, NTPC

15

4. Accident Investigation & Records PURPOSE OF ACCIDENT INVESTIGATION

The purpose of Accident Investigation is to discover hazardous conditions and practices so that accidents from similar causes may be prevented. This is accomplished through: FIRST

:

Detailed investigation of each individual accident to discover the Causative factors involved

SECOND

:

An analysis of the factors found

THIRD

:

Recommendations for the corrective action, based on the Investigation and finding.

The idea of seeking to fix blame should be definitely avoided, for where this is allowed to enter, an attitude of covering up develops amongst the employees which makes it difficult, and many times impossible, to get all the facts. Care must be taken to make sure that every person involved – the supervisor, the foreman, the workman and the person conducting the investigation is aware that the sole purpose is to be prevent future accidents and not to fix blame. If this is done, there will be no incentive for anyone to withhold essential information and the people conducting the investigation will also have full facts to aid them in order to prevent further accidents. if a policy of thoroughly investigation each and every accident is established, a wealth of information on preventive measures will be gradually built up. It will also provide valuable finding from the investigation on which inspection can carried out and the particular hazards watched carefully. Proper investigations are part of the foundation on which accident prevention is founded.

© PMI, NTPC

16

PRINCIPLES OF ACCIDENT INVESTIGATION Accident investigation is actually a simple procedure but certain principles must be followed if maximum results are to be obtained. FIRST

:

common sense and clear thinking are a must.

SECOND :

The people conducting the investigation should be familiar with the equipment, operation and the process so that they have an understanding of possible

hazards in any give

situation. THIRD

:

The investigation should not be under the control of the Foreman of

the Supervisor of the department in which the

accident occurred, because if they are, it is difficult for them to given unbiased Opinion about the situation involved. There attitude should be one of cooperation with foreman to discover and secure a means of correcting or eliminating the hazards. FOURTH

:

Each clue that is uncovered should be investigated thoroughly because quite often a clue that may appear to give a reasonable answer to a problem will give an entirely different light if it is explored further.

FIFTH

:

Since physical hazards can be eliminated, appropriate means of correction of the unsafe practices should be sought.

SIXTH

:

No investigation should be considered completed until a definite Recommendation for corrective action is made.

© PMI, NTPC

17

SEVENTH

:

It is advisable to have more than one person to investigate the accident due to the fact that the old saying that two heads are better one still applies and better constructive criticism can be obtained this way.

EIGHTH :

Investigation should be carried out as soon as possible the occurrence , so that

the conditions do not change and

details get forgotten. The above principles, if followed, will have a good effect on the other workman in an area as they see the importance the management attaches to the matter of safety if immediately investigated because we must remember that once an accident occurs the seriousness of the accident is largely a matter of chance. Usually, no one has any control on the severity of an injury once an accident has occurred.

WHO SHOULD MAKE INVESTIGATION Generally speaking, it makes little difference who investigates an accident if the principals mentioned earlier are followed. Certainly the safety officer/supervisor should be on the investigation along with the plant committee, but one of the things that must be watched is that group investigating should not be too large because of the time element involved. If the group feels that because of the large number involved not too much time can be spent, then there is the possibility that there will be a lack of lack of thoroughness in the investigation as there will be tendency to hurry. A smaller group can often spend more time and come with much better results. Actually every supervisor / foreman should be required to personally investigate every accident of workman under his jurisdiction in order to improve his own supervisory performance as well as to make sure that he is thoroughly acquainted with accidents that occur in his department. Committees of workers themselves can be especially valuable in bringing to light physical hazards and hazardous practices, which are not readily discoverable by persons who are not actually doing the various jobs. © PMI, NTPC

18

When an accident occurs, the first concern, naturally, is for the injured person, but when his welfare has been provided for, investigation should be next thing. Every person who might possibly has information bearing on accident being investigated should be interviewed and a full record made. The use of signed statements by the persons questioned is rarely advisable, since many workmen are suspicious of any attempt to have them sign anything associated with an accident with the idea of blame and punishment. Usually accurate reports and statements can be obtained by careful investigation. Thoroughness is something that is a must in an accident investigation as there is a temptation to carry the investigation only so far as is necessary to discover the means of prevention. But in the majority of accidents more than one hazardous condition or practice is involved.

WHY RECORDS Records are the foundations of a scientific approach to accident prevention. The prime purpose of keeping records is to: --

Furnish the information necessary for the compensation of injured persons

--

Serve as a guide to preventive effort.

Records provide the safety – man with an objective evaluation of his safety programme. They identify high accident rate department and provide the information needed to remove accident causes and hazardous conditions. More specifically, records may be used: --

To create interest in among supervisors by furnishing them with information about the accident experience in their own department.

© PMI, NTPC

19

--

Determine the principle accident source so that efforts may be concentrated where the greatest reduction in accidents can be brought about.

--

Provide supervisors and the safety committee information about the most frequent unsafe practices and unsafe conditions so that these persons can utilize their time and efforts to the best advantage.

Judge the effectiveness of the safety programme by comparison with the past experience and by making similar comparisons with companies in like operations.

STEPS IN RECORD KEEPING The following are the steps in record keeping --

Obtain a report of every injury (This should include all first aids cases).

--

Classify and record each injury

--

Analysis the circumstance and causes of accidents.

--

Prepare a monthly summary report showing the number of accidents and breakdown analysis showing the nature of injury along with preventive steps taken or recommended.

--

Prepare a yearly report including all factors as to injury agency, medical and compensation costs, time lost, etc, to provide an overall picture to highlight accident trends.

BASIC RECORDS The basic records, which should be kept, are: --

First – aid report to accident

© PMI, NTPC

20

--

Supervisor’s report of accident

--

Monthly reports

--

Accident analysis forms accident analysis charts.

--

Departmental and safety committee report.

--

Details to provide information necessary for computing accident frequency and accident severity rates

--

Yearly summary reports:

--

To show the trend of the safety performance during the year.

--

To show comparisons with experience of previous year.

ACCIDENTS REPORTS Because Accident Report Forms are the basis for the all accident records, essential to include the following information in the accident report. To be value, they must be complete and factual. WHO

the injured person or persons were. Also note others involved.

WHEN

the accident took place ; Date, Shift, Time.

WHAT

Actually happened. Reconstruct as fully and accurately as possible what happened just before, during and following the accident Be careful to indicate the sources of information and any fact which can only be assumed. If necessary, sketch a diagram to help to explain all the events.

HOW

The persons were injured. Describe the injury itself Indicate the part of the member of the body injured (toe, finger, back, head, arm etc.)

© PMI, NTPC

21

Also describe the nature of the injury (burn, sprain, fracture, laceration, etc.)

Why

the accident happened. Make a full analysis of the causes: --

Study conditions at the scene of the accident. What hazards were present? Did an unsafe condition cause the accident? Did an unsafe act cause the accident?

--

Analysis contributing causes, (Slips, falls. drops, etc.)

--

Consider personal causes; Study the employee’s safety record for indication of recurring accidents.

--

Include action necessary or already taken to prevent similar accidents in future.

An accident report should not be considered “another paper work practice” it can and should be of prime importance. In may cases it has been found that the supervisor of foreman fill out an accident report as briefly as possible. This should not permitted because no one is in a better position to tell the story than the foreman and often one is in a better position to advise a cure for a specific condition which exists, To be effective, preventive measures based on complete unbiased knowledge of accident should be made by the supervisor who is in charge of the department were the accident occurred. The monthly report should be complied from the first aid report and the supervisor reports. The Yearly report should be complied from the monthly reports and Medical Aid and Compensation Cost statements sent by the firm to the statutory agencies.

© PMI, NTPC

22

5. Techniques Techniques Of Discovering Hazards To have a safe work place it is essential that apart from efforts towards accident prevention, a comprehensive hazard programme should exist in an organization. Hazard Control is that function which is oriented towards recognizing, evaluating and working towards eliminating hazards and their destructive effects find the work place.

HAZARD-A DEFINITION Hazards Control Programmer Hazards are causes of accidents, Defining it strictly, a hazard is any existing or potent ional condition in the work place which by itself, or by interaction with other factors result unwanted affects of injuries properly damage or other losses.

Hazard Identification The essential components of hazards control programme are: Here information regarding hazards is collective from various sources. Specific jobs are subjected to analysis regarding their potentiality for hazards.

Ranking hazards by risk Here the probability (Frequency) and consequences (severity) are analysed, and prioritisation for control is done.

Establishing preventive and control measures Here solutions to the control of hazards are identified, and these measures are executed.

© PMI, NTPC

23

Monitoring Continuous follow- up on isolated procedures through various techniques like periodic inspections, measurement and accident investigation.

Evaluating programme effectiveness and feedback A periodic evaluation of the programme is essential and feedback for connective actions should be given.

HAZRAD CONTROL – RESPONSIBILITY Hazard control is not just a distinct function carried out by specifically allocated persons alone. Like all safely activities, it is a line responsibility; it is integral part of each persons jobs. It is a collaborative effort between departments, with each department sharing in its responsibility. Planning departments prepares specification, which is free from hazards,

and

comply

statutory

requirements.

Design

executes

these

specifications keeping in mind operating conditions and job requirement; it assists other departments in hazard analysis. Production ensures hazard control by hazard analysis and continuous monitoring. Maintenance sticks to its preventive maintenance schedules, ensure that its work maintains the designed standards, and implements solutions to specific problems identified in hazard analysis. Even Material purchase occupies a crucial position by providing specification for bought out items, that conform to safety and health criteria, and ensuring

that no hazards arise during the transportation of such items,

especially chemicals. The specific team for hazard identification, evaluation, and establishing controls, will normally consists of persons drawn from Safety, Production , Maintenance, Casing and Planning.

© PMI, NTPC

24

HAZARAD CONTROL – WHEN The activity of hazard control is a continue and ongoing one .it is performed before the plant is constructed and before an operation is established: through hazard

analysis at the planning and design stage. It is performed in the

operational phase: by programmes of inspections and monitoring.

It is also

performed when the system has broken down: after the event, so to speak through accident investigation and analysis.

TECHNIQUES FOR HAZARD IDENTIFICATION A number of techniques exist to discover hazards. Many of these are composite, i.e. they individually cover hazards identification, evaluation and control. They are --

Hazards Analysis *

Failure Mode and Effect Analysis

*

Fault- Tree Analysis

-

Job Safety Analysis

-

Plant Safety Inspections

-

Hazard Measurement and Testing

-

Safety Surveys / Audits

-

Actions Investigation and Analysis.

Each technique is subsequently discussed separately

© PMI, NTPC

25

HAZARD ANALYSIS These are formal analytical techniques, which are used to identify hazards and acquire failure data regarding a system. These are of two types, the inductive, and the deductive. The inductive method uses observable data to predict what

can happen, It

begins with the component parts of the systems, and evaluated what impact these individual failures will have on operation of the system as a whole. An example of this is Failure Mode and Effect Analysis. The deductive method analysis how failures take place. It begins with the failure of the system and then identifies how the components could contribute to the failure Fault Tree Analysis is one of this type.

Failure Mode and Effect Analysis In FMEA, the failure or malfunction of each component is considered, including the mode of failure. The consequences of the failure are traced thought the system, and the ultimate impact on system functioning is evaluated: A disadvantage of this method is that since only one failure is considered at a time, interaction of two or more simultaneous failures is not considered, and therefore certain synergistic possibilities are over- looked, This technique is widely used in the space and Nuclear industry, and can also have wide application in the chemical process industry. A form in FMEA is reproduced below: -

© PMI, NTPC

26

Format for FMEA

Fault tree Analysis (FTA) In FTA, the analysis begins with an undesired event, all possible happenings that can contribute to this event are listed, and are put into a diagram in the from of a tree. These happening are each component faults: Which can constitute

either

sequences of event leading up to, or alternative modes of the selected system fault, An example of a fault tree used in the case of shaping the wire rope of a hoist is as shown below:-

© PMI, NTPC

27

Job Safety Analysis (JSA) JSA is a procedure used to review job methods at the design stage itself to ensure safe working. Howe ver, It may also be used successfully to uncover hazards that may have developed after production started: or that resulted from change in work procedures.

PRODCURE The procedure of job safety analysis is simple and consists of 4 basic steps.

Selecting the job Jobs with potential for more frequent accidents, severity of injury and new jobs in

© PMI, NTPC

28

which the accident potential is unknown should be selected first.

Breaking the job down The Job should be broken down to basic steps in the hazards in the jobs proper sequence. Descriptions of each step should give the idea of what is being done. A job safety breakdown sheet giving the following 4 heads is used for analyzing the hazards in the jobs. Step No.

Operation

Hazard

Precautions

Identifying the Hazards The person examines all possibilities of accidents in each step. He should note down these hazards under the second column of break down sheet. For identifying the hazards, he should watch the operations as many times as may be required and also have discussions with the operators concerned and others who have knowledge of the job.

Developing Solutions The solutions to hazards in the job may be worked out by: --

Finding a new method or procedure of doing the job.

--

Reducing the necessity or frequency of doing a job that is hazardous, and

--

Changing the physical conditions that create the hazards.

After the precautions to be taken in each step are developed, these safety precautions are to be incorporated in the job or process sheets. Job safety instruction sheets containing safe- guard and safe procedures to be adopted in different jobs, particularly the hazardous ones could also be made out and is issued to the supervisors and operators and necessary training imparted to them, so that the y could follow correctly the procedures of safe- guards laid down. If

© PMI, NTPC

29

accidents are happening in spite of complying with procedures laid down based on job safety analysis, the analysis, obviously would need further review.

EXAMPLES The procedures of job safety analysis are illustrated by an example.

PROBLEM

:

In a foundry, ferrous casting weighing about 20 Ibs are fettled by hand on pedestal grinder (12” wheel diameter). The casting are stored on one side of the grinder from they are picked up, fettled on the grinder and replace on the floor on the other side of the machine. Analysis technique and determine the hazards and the safety precautions to be taken.

© PMI, NTPC

30

© PMI, NTPC

31

PLANTS SAFTY INSPECTIONS Inspections are that monitoring function conducted in the organization to locate and report existing and potential hazards which have the capacity to cause accidents in the work place. Inspections are not primarily aimed at unearthing new types of hazards; though that may be achieved also; but rather at locating and correcting known hazards.

TYPES OF INSPECTIONS There are basically 2 types of inspections either continues or conducted at intervals. Continuous

inspections

are

conduced

by

those

employees

like

maintenance technicians, production supervisors. Tools inspectors, etc,; as part of their specific job responsibilities. Any apparent or potential unsafe act or condition is corrected immediately or reported for corrective action. The checking of controls by a crane operator or the checking of machines by the new operator in each shift, also fall into this category of inspection.

© PMI, NTPC

32

As against ongoing inspections, planned inspections are conducted at intervals. These are of four types: periodic, intermittent, general and special. Periodic

inspections are well planned and made at regular intervals, the periodicity being decided according to the hazard potential involved. Machinery, Material, Handling Equipment. Fire Fighting Equipment,other equipment, tools, storage methods should all be inspected regularly. In such cases, it is useful to follow a checklist, A typical checklist which can be used on construction sites is included at the end of this handout, The checklist enables the inspector not to miss points and readily detect deviations. Certain items

like

pressure hoists, lifts etc are statutorily required to be checked by competent Persons. Intermittent

inspections are unannounced inspections made at irregular intervals. These may be made by safety personnel, safety committee, supervisor and usually cover a particular department of work area.

A general

inspection is planned inspection of places, which do not receive periodic inspections. It covers especially those areas which’ as one ever visits’ since ‘no one ever pets hurt” This may be outlying areas of the plant, storage areas, locations at heights like roof, EOT Carnes & Walkways etc. It also covers inspections or regular areas under abnormal conditions like second shift, weekly off under artificial lighting.

Special

inspections are those made based on specific needs, i.e. of those areas where particular type of hazards are suspected, This include high accident frequency areas or construction

© PMI, NTPC

33

sites of locations where new equipment is under installation, Other examples are inspections during campaigns like fire prevention week: or health surveys determine the existence of an occupational illness.

Who conducts Inspections? Inspections are the responsibility of various functions in the organization. Continuous inspections are normally the responsibility of the line personnel, including the first line supervisor and maintenance engineer. However, it is important that these persons also conduct inspection according to a checklist at some frequency. Periodic inspections must be conducted by middle and senior

management

from the line, The safety officer should be associated. Apart from the hazards detected, the mere presence of a senior manager in the inspection team sends the indirect message home of the top managements concern for safety. As already pointed out, workers must be made to inspect the plant and machinery under control in each shift, and given relevant feed back.

Inspection Procedures The persons making inspections should be familiar with the equipment, tools, the process and operations and should ha ve adequate knowledge of hazards associated with these They should also be a familiar with the company rules and polices and also dealing with safety and health, The inspectors should be equipped with data based on a detailed analysis of previous accidents in the plant. An inspection Check List often proves to be very handy and will eliminate the chances of overlooking some of the sources of accidents A specimen of broad checklist is given in the annexure. Detailed checklist could be dawn up for individual plants or sections.

© PMI, NTPC

34

The inspection should be systematic, and thorough, The Inspector should not depend on his memory and make complete notes of the unsafe conditions which are discovered at the time of the inspection. This can be used at the time of writing the inspection report. The implementation of suggestions arising out of inspections is to be carried out by

the

various

departments

concerned

with

production,

engineering,

maintenance etc. and therefore it is important that the recommendations are discussed, Wherever necessary, with the concerned persons.

Reporting and Follow- up The inspection report should be clear and concise with enough explanation to make it understandable. Copies of the recommendation should be sent to the concerned persons for implementation. Progress should be reported to the management at regular intervals. Periodic check should be made until they have been completed.

HAZARAD MEASUREMENT AND TESTING This technique is applied to the special case of hazards, which are present in the work environment. These may be physical hazards like noise, heat stress, inadequate illuminations. Radiation etc. or chemical hazards like airbome dusts, gases or fumes. The degree to which the hazard is present is measured (e.g.) noise level in decides or airbome concentration in pp, parts per million

by

volume) The concentration of these hazards can be measured by personal monitoring – where the measurement device is placed as closed as possible to the site at which the contaminant enters the human body or Environmental monitoring where in the concentration if the work station is measured. Two other techniques exist which use the change in the human body as a measure of exposure to chemicals, biological monitoring measure changes in composition of body fluid, tissues or expired air to detect the level of absorption,

© PMI, NTPC

35

while Medal monitoring examines the workers to see their physiological and psychological response to the contaminant.

SAFETY / AUDIT /SURVEY A Safety Audit subjects each area of company’s activities to the systematic, critical examination with the object of minimizing loss. Every component of the total system is included, e.g. management policy, attitudes, training, features of the process and design, layout and construction of the plant; operating procedures emergency plans: personal protection standards; accident records; etc. A safety survey on the other hand is a detailed examination of a narrower field of activity, e.g. key areas revealed by the Safety Audit; individual plants: Procedures or specific problems common to the works as a whole. The audit is an evaluation of the company’s organization and procedures, an appraisal with a view to detection weak points and initiating corrective measure. It should normally be conducted once a year; preferably by an outsider to the organization or by another branch of the same organization. The audit should be initiated by the top management, or with their full support. The Audit team submits a written report. The report and its recommendations should be discussed and a minute action plan for their implementation should be drawn

up.

The

top

management

should

receive

intimations

of

the

implementations of the Audit report periodically.

ACCIDENT INVESTIGATION AND ANALYSIS Accident investigation and analysis are useful tools to reveal hazards. Appropriate corrective action taken on this basis is a keystone to accident prevention.

© PMI, NTPC

36

A systematic and thorough investigation of each accident helps build up a fund of information. The analysis of rates to indicate high frequency & severity locations, as well as the identification of accident are useful pointers.

Accident investigation The basic principles of good investigation are :−

It should be done on the spot, immediately after the accident by an independent authority. The scene of the accident must not be disturbed until after investigation is over.

−

The investigation should be fact-finding, and not fault finding.

−

Both types of causes; i.e. unsafe acts and hazard conditions must be identified.

−

All accidents – whether they result in injury or not must be investigated. The same accident without injury today could lead to a serious injury tomorrow.

−

The concerned workers, supervisors and departmental incharges must be associated with the investigation.

−

A written report must be prepared which identified the preventive and corrective measures required. This must be sent to the senior man, who should issue instructions to implement the measures.

Accident Analysis There are standard statistical to identify high risk areas based on the accident data Two standard formulae are frequency Rate and severity rate:

© PMI, NTPC

37

© PMI, NTPC

38

© PMI, NTPC

39

© PMI, NTPC

40

CALCULATION OF ACCIDENT RATES TO compare the number of accidents in one factory with that in another in the same branch of industry, it is necessary to take into account the differences, which may result from differences in the numbers of workers, employed in the two factories. This can be done calculating the accident frequency rate i.e. the number of injuries for health for each million work- hours of exposure. This is expressed by the following formula, in which F represents the frequency rate.

F

Number of injuries X1,000,000 -----------------------------------------Total work- hours of exposure.

=

Example:

An undertaking with 500 workers, working 500 weeks of 48 hours each, had 60 accidents causing injury one year. Owing to illnesses, accidents and other reasons, the workers were absent during 5 per cent of aggregate working time. Thus the total number of work – hours (500X50X48= 1,200,000) has to be reduced by 5 percent (60,000) giving the real number of work – hours of exposure as 1,140,000, This being so-

F

=

60 X 1,000,000 ------------------------ = 52.63 1.140,00

This frequency rate indicates that, in one year about 53 accidents causing injury occurred per million work hours. So far, only the number of accidents has been considered, and this is not a very exact measure of the effect of accidents. To obtain a better idea of the situation, the severity rate must also be calculated. The international resolution of the method of compilation of severity rates, adopted in 1907 by the sixth International Conference of Labour Statisticians, was not retained by the Tenth Conference in 1962. This was mainly because some countries calculate the severity rate on the

© PMI, NTPC

41

basis of the total number of days per thousand work- hours of exposure, other countries use the time expressed in days per million work hour of exposure and yet other countries use as a denominator the average number of employees of insured persons, or 300—day work- years. Example:

If in the example given for the calculation of the frequency rate, the number of days lost as result of 60 accidents was 1,200, the severity rate(s) would be as follows:

S

=

1,200X 106 ----------------- = 1.053 1,140,000

This means that in a year about one day was lost per thousand work-hours of exposure , or 1,053 days per million work– hours of exposure, or on the basis of 2,400 hours per year, 24 days per worker.

© PMI, NTPC

42

6. Investigation Of Accidents The purpose of an accident investigation is to find the causes of the accidents in order that appropriate measure can be taken. The National Safety Council in United States gives the reasons for accidents investigation as: --

To learn accident causes so that the similar accident can be prevented by mechanical improvement, better supervision or employee training

--

To determine the “change” or deviation that produced an “error” that in turn resulted in an accident (system safety analysis);

--

To

publicize

the

particular

hazard

among

employees

and

their

supervisors, and to direct attention to accident Prevention in general --

To estimate extent of loss/ damage of manpower/man – hours plant and machinery, etc; and

--

To make suggestion for prevention of recurrences of similar of related nature of accidents.

Basically whatever type of investigation is undertaken, it answer the following questions: −

WHO was injured?

−

WHAT happened and WHAT were the contributing factors?

−

WHEN did the accident occur?

−

WHERE did the accident occur?

−

WHY did the accident occur?

© PMI, NTPC

43

AND finally, and most importantly: −

HOW can a similar accident be prevented from happening again?

There are several number of conducting an accident investigation which are neither too complicated nor too time consuming. For minor accidents, good results have been obtained by the following method, The victim goes to the first – aid room, after treatment, is given an accident investigation form to take to the supervisor; the later fills it and sends it to the safety engineer who, according to circumstance, may decide to make a more detailed investigation (or to take some other action) or simply to file it for statistical purpose or for discussion in the safety committee, This method has the advantage of stressing the responsibility of the supervisor for safety in that particular

department. However in many

cases, accident investigation forms may be filled in by the victim upon arrival at the medical center for Treatment. An accident investigation should always be made on the spot. It will be much easier if the investigator finds the situation at the scence of the accident exactly as it was when the accident took place. Consequently, after an accident, the site should be left undistributed unless changes have to made to ensure the safety of persons or to prevent further damage. Whether the site has been distributed or not, it is desirable to try to reconstruct the sequence of events before, and during, the accident, possibility with the assistance of injured person and with the co- operation of witnesses, The investigator should carefully inspect the site and then examine the witnesses. In many cases the causes of the accident will be discovered in this way, but in some cases – e.g., where breakages of metal are involved – it may be necessary to seek technical assistance. If a part of a piece of apparatus, such as a chain or a wire rope, breaks, it is desirable to know the causes of the failure and for this reason, the material should be examined and tested to discover whether it was unsuitable, had been

© PMI, NTPC

44

maltreated or was just worn out. The necessary information may be provided by a microscopic examination, by tests carried out on a sample of the material, or by chemical analysis. Example:

A chain used in a hoisting apparatus with a maximum safe load of 500 kg. Broke when 700 kg. was lifted. The chain was overloaded, but this circumstance in itself was not sufficient to explain why it broke. Tensile tests on two links showed that they broke when the load was about 2500- 2600 kg. Links tested by hammering their narrow and unit the long side became the short side did not show any defect. A microscopic examination, with magnification of 200 and 1,000 showed ageing phenomena i.e changes in the properties of the material occurred with the passage of time. These aging phenomena resulted in decreased resistance to shock, such as that which occurs in working conditions, and this had caused the accident. Often accident investigation is concerned with both responsibility and prevention, and this may seriously hamper discovery of the cause. If the persons questioned feel that someone will be blamed as a result of the investigation, those who consciences are not quite at ease may give incorrect or incomplete information. It may then be impossible to find the cause and consequently to devise means of prevention. In accident investigations, it should always be borne in mind that prevention of accidents is much more important than the more apportioning of blame.

© PMI, NTPC

45

INVESTIGATION – PRODCURE I.

DUTIES 1.

Was the person concerned carrying out a Task that was part of his / her normal duties?

2.

What was abnormal or different?………………

3.

Was the task within job specification / description of the person concerned.

4.

Yes/No

If no, (i)

5.

Yes/No

In what way was it outside job Specification/ description?………..

Yes/No

ii)

Who should have carried the task?

(iii)

Why should that person perform the task?………………

Was the person involved in activity associated with work but not directly related to task?

Yes/No

If yes, The activity in which the person was engaged …………………………… II.

SUPERVISION Was the persons immediate supervisor present in the area at the time of accident

Yes/No

If yes, a)

Location of supervisor at the time of accident ……………………………….

b)

Any information given by the supervisor prior to leaving the area………………..

c)

Was the accident reported immediately and to whom………………………………….

© PMI, NTPC

46

If No,

III.

a)

Why was there a delay……………………………

b)

How long was the delay………………………………..

INFORMATION Was the person concerned specifically warned of the hazards of the task?

Yes/No

If NO, a)

Was the hazards known to all?…………………………..

b)

Who know them?……………………………………….

IV

INSTRUCTION

1.

Was the person concerned instructed to carry out The particular task / job ?

Yes / no

If No, a)

Why was the task undertaken?…………….

b) Was there a change in intention? If so, state reason of change……………………………………… c)

2.

Was task/ activity part of the total job?………………………

Had the person concerned been given written or verbal instruction in the general hazards associated with the task/ job? Yes/No If Yes, a)

Method of instruction and when given…………………………..

b)

Outline the instruction given…………………………………..

© PMI, NTPC

47

3.

Was the work carried out according to instruction or normal practice? If No, a)

In what way was the task carried out that was different to normal practice?

V.

TRAINING

1.

Was task/ job within the capability of the person concerned

Yes/No

If No, a)

2.

What additional training was required …………

Was the person concerned familiar with Type of plant/equipment, Tools etc?

Yes /No

If No, What knowledge/skill was lacking?…………………. 3.

Had the person concerned been trained to carry out the task/job safety?

Yes /No.

If Yes, a)

What training had been given?……………………..

4.

Was the job / task carried out by the prescribed method and the method used………………………………

VI.

PROTECTION Was the personal protective equipment been worn?

Yes /No

a)

Was it is supplied to him?

Yes /No

b)

Was it in good condition?

Yes/No

© PMI, NTPC

48

c)

Was it practicable to wear?

Yes/No

d)

Was it adequate to deal with hazards? If No, Why?………………..

Yes /No

VII

PLANT /EQUIPMENT/ PREMISES 1.

Were Plant/ Equipment/ premises in normal condition?

Yes/No

If No, state What modification or alternation had been made?……………….. 2.

Were means for controlling emergency or emergency stops. etc where located near to hand?

Yes /No/NA

If No, Would such control have reduced that consequences or eliminated the accident…………………..

3.

Were guards. Protective devices effective And/ or secure?

a)

In what cases why was the guarding of the machine / Plant insecure or ineffective………………………..

4.

Were warning notices displayed, Warning persons of hazard or to used protective equipment etc.

Yes/No/NA

Yes/No/NA

If Yes, Type and content of notice…………………………………. If No, Whether workers were warned of hazards and way of working Yes/NO/ NA.

© PMI, NTPC

49

What they were told about………………………………………….

5.

Were Operating controls, pipelines, tanks, etc. clearly marked?

Yes/NO/NA

If No, a)

Reasons why not clearly marked…………………

b)

What additional marketing, etc, Could be made…………………………………..

6.

Was the approach to work place vice versa was safe Yes/No/NA If No, What was unsafe?……………………………………..

VIII.

SYSTEMS 1.

Are procedure / instructions laid down for the task/ job?

Yes/NO/NA

What procedure could be laid down?……………………… 2.

Is there a system for a monitoring that procedure/ instruction are followed…………………..?

Yes/NO/NA

What method of monitoring could be used to ensure that the procedures are followed ?…………………………. 3.

Are “ Permit to work” normally issued For the type work

Yes/No/NA

If No, Why are they to work issued? Was a permit to work issued?

© PMI, NTPC

50

If No

Why permit was not issued?…………………….. IX.

ENVIROMENT Did any of the following natural conditions lead to accident? (Tick mark) Rain

X.

--

Typhoon

--

No

If accident was caused due to following: Confined space Condition of floor Condition of scaffold/ platform Condition of ladder Illumination Poor House- Keeping Other (specify)

© PMI, NTPC

51

7. Procedure For Reporting Of Accidents/ Drangerous Occurences OBJECTIVE In order to make prompt report of accidents and dangerous OCCURENCES to comply with requirements/ Obligation under different status; and to inform the concerned authorities within the organization for keeping complete information of accidents for the record, for analysis, which will be of help in taking remedial measures for the accident prevention in future; it has been decided to introduce a procedure for reporting of accidents / dangerous OCCURRENCES in NTPC.

PROCEDURE IN CASE OF ACCIDENTS CAUSING INJURIES/ FATALITIES An office of the Section will immediately refer the injured to the corporation’s Hospital / Dispensary/ First-aid unit with a preliminary report on From-1 (Annexure-1). In addition he will inform about the accident to Departmental Head, Personnel head and Safety Office on telephone with full description of accident. In case of study to contractor’s employees, the contractor will immediately inform accident /dangerous occurrence to NTPC office Incharge and Safety Office himself on telephone or through special messenger. Office In charge of NTPC, will submit information of accident as above. In case the injured has come / is taken directly to hospital/dispensary/ first–aid unit – in charge of unit will uniform about the injury to Departmental Head in from II( Anne xure-II) with a copy to plant Personnel

Head and plant Safety

Officer. He will immediately inform of serious cases by telephone also to Departmental head, personnel Head and Safety Officer.

© PMI, NTPC

52

Subsequently the concerned department / section in charge will prepare a detailed report of accident within 4 Hours of the accident in from –III(Annexure III) and will submit one copy each to the General Manager and Personal Head. Third and fourth copy of the report will be sent to Safety Officer and he will retain fifth copy for the departmental record. The safety officer will intimate the accident to concerned Statutory Authorities as per the provisions of relevant Act/Rules. However the State Rules concerned should be referred to for additional provisions. If any. The Safety Officer will also submit a copy of Form –III along with his comments to Corporate center safety Section within one week of occurrence of accident. Safety Officer will send accident report of each calendar month to Corporate Center Safety Section in From–V (Annexure–V) before fifth day of every succeeding month. In case of no accident, a ‘Nil” report should be sent. In case of fatal accident, information of the accident will be immediately intimated to Corporate Center Personal by telegram / tele x/ wireless.

PRODUCURE IN CASE OF DANGEROUS OCCURENCES As Prescribed under the relevant rules made by the State Government with reference to the provision of Section 88- A of the Factories Act, a

schedule of

some common dangerous OCCURREANCES is given in Annexure - VI. In case of dangerous occurrences, the same will be informed by Section In charge to Safety Officer, Departmental Head and Personnel Head in From – VII (Annexure – VII) Within 4 hours 4 . The Safety Officer will intimate such dangerous OCCURRANCES to statuary Authorities as indicated in the schedule at Annexure VI prescribed by the concerned State Government

© PMI, NTPC

53

ROLE OF CORPORATE CENTRE Corporate Centre Safety Section shall put up monthly accident/ dangerous occurrence report to GM (P&A) Director (P) for information. Corporate Centre Safety section will issue guidelines to various units on accident prevention activities from time to time, as may be deemed necessary.

© PMI, NTPC

54

ANNEXUR-1 FROM -I

National Thermal Power Corporation Limited ----------------------- Super Thermal Power Project /Station To In charge ------------------- Hospital / Dispensary/ First – aid Unit ----------------------------------------------------------------Subject: Accident of Shri / Smt---------------------------------------------------Shri / Smt.-------------------------------- is referred to your hospital for Treatment. The Details of the injured and incident are as below:

1.

Designation of Injured

: -------------------------------------------

2.

Employee No.

: ------------------------------------------

3.

Department

: ------------------------------------------

4.

Date & Time of Accident

: ------------------------------------------

5.

Details of Accident

: ------------------------------------------

6.

Case of the Accident

: -------------------------------------------

Date:------------------------------------------

Signature ---------------------Name---------------------------Designation-------------------Department--------------------

© PMI, NTPC

55

FORM-II

National Thermal Power Corporation Limited ------------------Super Thermal Project / Station Dated:-----------------No. To The Head of Safety, --------------- Project. Sub: Work Related injures.

Dear Sir, Shri …………………. S/0 Shri ………………….. Age ……………….. Years employed by…………………. Sub Contractor of……………. Dept. of NTPC has reported for treatment of injury in his hospital. The details of injury are as below: Nature of injury 1. Laceration/Contusions 2. Bums 3. Amputation 4. Fractures 5. Puncture wound 6. Multiple 7. Electric shock 99. Not Known

Fatal

permanent

Part of the body injured 1. Head. 2. Eyes 3. Face/neck 4. Chest 5. Abdomen 6. Spinal column 7. Hands and shoulder 8. Legs and perils 9. Multiple 10 Others 99 Not known temporary Expected

Disablement……% Disablement……………….Days This is for your information and necessary action. Signature………………………… Name of M.O……………………..

© PMI, NTPC

56

© PMI, NTPC

57

© PMI, NTPC

58

© PMI, NTPC

59

© PMI, NTPC

60

ANNEXURE – VI.

National Thermal Power Corporation Limited ---------------- Super Thermal Power Project/ Station DRANGEROUS OCCURRENCES i)

Bursting of a boiler or vessel used for containing steam under pressure greater than atmospheric pressure.

ii)

Collapse of failure of a carne, derrick which hoist or other appliance used in raising or lowering persons or goods, or any part thereof. Or the overturning of a crane.

iii)

Explosion of fire causing damage to any room or place in which persons are employed.

iv)

Explosion of a receiver or container used for the storage at pressure greater than atmospheric pressure or any gas or gasses (including air) or any liquid or solid resulting from the compression of gas.

v)

Collapse or subsidence of any floor, gallery, roof, bridge, tunnel, chimney, wall or building forming part of the factory with in the compound of factory.

vi)

Leakage of any dangerous gas /chemical.

Note: 1.

The above is only illustrative.

2.

A list/ schedule of dangerous occurrences are prescribed in the rules framed by the State Governments reference to Section 88-A of the Factories Act, 1948, which should be referred to by the project/ Establishment.

© PMI, NTPC

61

ANNEXURE – VII

National Thermal Power Corporation Limited --------- Super Thermal Power Project / Station DEPARTMENTAL REPORT OF DANGEROUS OCCURRENCE 1

Time of occurrence (a) Date --------------------------------- (b) Hours--------------

2.

Nature of the dangerous occurrence

3.

Equipment involved

(a)

Name------------------------------------

b)

Manufacture----------------------------

c)

Use---------------------------------------

d)

Location in Building----------------------------------

4.

Approximate length of service of equipment ----------------------------------------

5.

a)

Parts damaged---------------------------------------------------------------------

b)

Date when last tested------------------------------------------------------------

c)

Nature and extent of damage -------------------------------------------------

6.

Apparent reasons of the occurrences-------------------------------------------------

7.

Was is due to willful negligence of anyone -------------------------------------------

8.

Was there any infringements of rules or instructions? ----------------------------

9.

Could this occurence be avoided ------------------------------------------------------

10.

What action is being taken to prevent reoccurrence -----------------------------------------------------------------

11.

Additional remarks-------------------------------------------------------------------------

Date---------------------------

Signature---------------------Name--------------------------Designation-------------------Department--------------------

To 1.

Personal Head

2.

Plant Safety Officers

© PMI, NTPC

62

8. Guidelines On Contribution Of Enquiry Committee And Conduct Of Enquiry In Case Of Accident/ Dangerous Occurrences OBJECTIVE With a view to investigate all accidents in order to examine each to examine each case in details and depth to find out the causes of accidents, the extent of losses

caused. The circumstance / individuals responsible and to obtain

considered recommendations for the prevention of recurrences in similar or related nature of accidents, it is has been decided to prescribe a guidelines for consulting committees for conducting enquires in case

of various

types of

accidents and dangerous occurrences.

APPLICABILITY The procedure shall be applicable in case of all accidents, caused in respect of its own employees or of contractors’ / associates of NTPC.

DEFINITIONS Non – reportable injury Non – reportable injury would mean an injury by reason of which injured is either not prevented, or is prevented from working for a period less than 48 hours immediately following the day of accident.

Disablement of Permanent Nature. Provided under the workmens Compensation Act, 1923 and shall include partial and total disablement of permanent nature.

© PMI, NTPC

63

Dangerous Occurrence As prescribed under the relevant rules made by State Govt, with reference to the provisions of section 88-A of the Factories Act.

PROCUDRE The Enquiry committee to the constituted for various types of the accident, the authorities competent to appoint enquiry committee and the constitution of the Enquiry Committees have been prescribed in Annexure-1, As soon as the accident occurs. The Safety Officer Concerned in the project, will immediately initiate in cases of A(i) and B(i) where he is to act an enquiry committee.. Wherever the Enquiry Committee is to be appointed by the HOP or GM, the Safety Officer will make a proposals as per guidelines , for approval of the concerned competent authority and issue necessary office order for the enquiry. Wherever the authority competent to constitute an enquiry committee is ED and above, the GM of project, shall immediately contact authority through quickest means of communication and take approval for the constituting enquiry committee, An office under for constituting enquiry committee in that

case be

issued by GM of the project. Wherever an Officer of an other Project/ Corporate Center has been prescribed Annexure 1 to be a member

of the committee , the GM of the project , shall

immediately contract the concerned controlling officer through the quickest means of communication for obtaining a name including in the committee . In case finalising the nomination of other project/ Corporate Center, may take time the GM of the project Concerned can still issue the order constituting the enquiry the committee indicating against the member: An Officer to be nominated by Corporate Center / Project concerned, The enquiry committee shall start

© PMI, NTPC

64

investigation

immediately

within

the

shortest

possible

time

from

the

communication of the order constituting enquiry. Normally the enquiry report will be submitted within one month from the date of notification of the committee. However, the competent authority feels it expedient under certain circumstances he may require the report to be submitted even earlier. The terms of the reference from the Enquiry Committee should generally include. a)

Determination of circumstances and reasons of the accident.

b)

Estimate of extent of loss/damage of manpower /man hours/ plant/ machinery etc.

c)

To the extent possible fixation of responsibility.

d)

Suggestion for the prevention of recurrence of similar or related mature of accidents, and

e)

Any other relevant aspect.

Occurrence of accidents involving loss/ damage of Rs.10 lacks or more and / or death shall be intimated to Director (Personnel) and Executive Director concerned by the quickest possible means to communication. Report of an Enquiry Committee in cases at A(v) to (viii), B(iii) to (v) and C as in Annexure- I will be sent to Director ( personnel ) Executive Director Incharge and Corporate personal immediately for action. Corporate Personnel Division will, on a regular basis analyse the reports, covering serious injuries and fatal accidents for remedial action. The authorities competent to constitute and order enquiry committee have been indicated Annexure –1 However, if it is considered expedient the Chairman and Managing Director, can appoint an Enquiry Committee constituted by the

© PMI, NTPC

65

authority prescribed in the Annexure –1, shall become in operative, While passing such order, the CMD can also include additional members in the Committee or alter the level of committees as deemed necessary.

© PMI, NTPC

66

ANNUXURE-I National Thermal Power Corporation Limited GUIDLINE ON CONSTITUTION OF ENQUIRY COMMITTEE SI No

Type of Accident

A

In case of Personal injury In case of non – reportable injury up to 2 persons Non reportable injury up to 5 persons

i)

ii)

Enquiry committee to be appointed by

HOD in whose Deptt. Accident has occurred

Not below the rank of Mgr.( not connected with the accident) Not below the rank of Sr. Mgr.( not connected with the accident) Not below the rank Mgr.(not connected with accident) Not below the rank of DGM/ Sr. Mgr/ Sr. Supdt ( not connected with the accident )

1. Safety officer of the project

- do-

-do-

-do-

ED

Not below the rank of DGM/ Sr. Mgr of other project / CC

1. An officer of the rank of Mgr./ Dy. Mgr. Of the project ( not connected with the accident) 2. Safety Officer of the project.

Non – reportable injury to more than 5 persons

-do-

iv)

Reportable accident causing minor/ temporary injuries

-do-

v)

Reportable accident causing major/ serious injuries like amputation of limbs/ other parts of body and / or injuries expected to result into disablements of permanent nature( partial or total ) Fatal accident of one person Accident causing fatal injury to one person but involving a number of persons

GM

© PMI, NTPC

Other members

Safety officer of the project

iii)

vi) vii

Enquiry Committee to be headed by

1. –d0-

1. –d0-

One officer at the Mgr./ Sr. Mgr. From CC or other project.

67

© PMI, NTPC

68

9. Safety Policy INTRODUCTION NTPC recognize and accept its responsibility of establishing and maintaining a safe working environment for all its employees. This responsibility arises from. --

Company’s moral responsibilities to its employees. To provide the best practicable conditions of work from the point of view of health and safety.

--

The obligation to consult with its staff and their representatives to implement policies and procedures developed as a result of discussions.

--

Statutory responsibility in respect of health, safety and welfare of employees emanating from relevant legislation such as the Factories Act. The Indian Electricity. Act., The Explosive Act, the Boiler Act etc.

COMPANY’S RESPONSIBILITY The Company shall take all such steps , which are reasonably practicable to ensure best possible conditions of work, and with this end in view the company shall do the following:. --

To allocate sufficient resources to provide and maintain safe and healthy conditions of work.

--

To take steps to ensure that all known safety factors are taken into account in the design. Construction, operation and maintenance of plants, machinery and equipment.

_

To ensure that adequate safety instructions are given to all employees.

© PMI, NTPC

69

--

To provide wherever necessary protective equipment, safety appliances and clothing , and to ensure their proper use.

-

To inform employees about materials, equipment or process used in their work, which are known to be potentially hazardous to health or safety.

--

To keep all operations and method of work under regular review for making necessary changes from the point of view of safety in the light of experience and up to date knowledge.

--

To provide appropriate facilities for the first aid and prompt treatment of injuries and illness at work.

--

To provide appropriate instruction, training, retraining and supervision in health and safety and first aid and ensure that adequate publicity is given to these matters.

--

To ensure proper implementation of fire prevention and the appropriate fire fighting service, together with training facilities for personnel involved in this service

--

To

ensure that the professional advice is made available wherever

potentially hazardous situations exist or might arise. --

To organize collection analysis and presentation of data on accident. sickness and incident involving personal injury to health with a view to taking corrective, remedial and preventive action.

--

To promote through the established machinery. Joint consultation in health and safety matters to ensure effective participation by all employees.

_

To publish /notify regulation. Instruction and notices in the common language of employees

© PMI, NTPC

70

--

To prepare separate safety rules for each type of occupation / process involved in a project.

--

To ensure regular safety inspection by a component person at suitable intervals of all buildings work places and operations.

--

To co – ordinate the activities of the company and of it contractors working in the company’s premises for the implementation and maintenance of safe system of work to comply with their legal obligations with regard to health. safety and we lfare of their employees.

THE RESPONSIBILITES OF THE EMPLOYEE The establishment and maintenance of best possible conditions of work is no doubt, the responsibility of Management. it is

also necessary that each

employee follows prescribed methods of work . He should take reasonable care for the health and safety of himself, of his fellow employees and

of other

persons who may be affected by his actions at work. With this in mind. employees should be health and safety conscious and:

Report

Potential ha zards.

Observe

Safety rules, procedures and codes of practice.

Use

With all reasonable care the tools , equipment, safety and protective clothing provided by the company; these items should be kept in good condition.

Participate

In safety course when called upon to do so.

Make use

Of safety suggestions scheme.

Take

An Active and personal interest in promoting health and safety at Work.

© PMI, NTPC

71

RESPOSIBILITES FOR IMPLEMENTATION --

The ultimate responsibilities for ensuring the implementation of the policy on health and safety at work rests on the NTPC Management the Corporate Personnel Division at the corporate level and the concerned General Managers at the project/ station level. The officer in charge of safety will be functionally responsible to the Corporate headquarter for ensuring the policy is promulgated and carried out in the manner expected

--

Immediate responsibilities for the safety at work is that of the Managers/ Executives of each department / Section who are responsible to prevent accidents invo lving members of their staff and other persons. it Is their instructions, compliance with which will ensure safe working and to require the effective use of approved equipment.

--

Accepted rules. Procedures and Codes of Practice which are formulated with proper regard to health and safety consideration must be strictly observed by all concerned Contracting agencies executing works should be made responsibe, through various measures including appropriate provisions in the contract, for discharging their safety obligations:

--

In designated areas of particular hazards the appropriate Executives and, before to authorize, in writing, the commencement of any work and, before doing so, personally to satisfy themselves that all necessary safe precautions have been carried out. Such Executive must themselves be Authorised, in writing as competent to perform these duties.

--

Safety Officers are appointed to advise on questions of safety all work including advice on the application in particular local situations of the systems of work implementation of Company’s Rules and Relevant code of practice in consulted in the interpretation of rules and codes being formulated by the Corporate Management and shall advise management

© PMI, NTPC

72

in investigation, analysis of accidents and circulation of appropriate statistics.

Major Site Incidents The General Manager at each project / station is required to ensure that plans are devised for action in the event of fire, major site incident or necessity for evacuation procedure. These plans must be communicated to all staff and rehearsed from time to time --

Fire – fighting and the formation of fire – fighting team on a voluntary basis will be encouraged by the project/station Management.

--

All accidents and dangerous occurrences will be reported immediately to the General Manager who will implement an established procedure to ensure that an investigation takes places and recommendations are made to prevent recurrence.

© PMI, NTPC

73

10. Industrial Hazards INTRODUCTION --

The fast development of industry and the extended use of power driven machinery has accentuated the occurrence of injuries. Man has to conform to the habit and pattern to work safely with the machines. Technical

factors

such

as

design,

construction,

operation

and

maintenance can greatly reduce unsafe conditions. Some of the hazards which exercise a positive bearing on the scope of this study may be classified as: *

Mechanical

*

Electrical

*

Chemical

MECHANICAL HAZARDS --

One of the mighty creations of man are the machines. They serve him so long as he exercise a positive control. The moment he forgets the rambunctious of the machine, he suffers injury and even fatality.

--

Common sources of mechanical hazards are, unguarded shafting, shaft ends, belt drives, gears pulleys. projections on rotating parts, chain and sprocket drives, any exposed components parts of machine., or power driven equipment which rotate rapidly or have considerably power and may catch the worker( his clothing, fingers hairs, etc.) entangling him in the machine before he can free himself; shear points where a part moving in positions or a moving object would have a scissor like effect on anything caught in between; any machine component which moves rapidly, which

© PMI, NTPC

74

may strike, crush, or otherwise; injure a worker; the points of operation where the machine performs its work; pressure vessel explosions; fly wheel hazards, etc. --

Important mechanical hazards relate to machines of all kinds, including transmission machinery, hand tools, handling materials, lifting and other appliances. It is true that every work place and every equipment has its own problems but experience has shown that mechanical hazards are the most spotted ones and responsible for the majority of accidents in work situations. Some of the hazards conditions of mechanical operations may be characterized as follows: a)

Inadequately Guarded

b)

Defective.

c)

Hazardous arrangement, procedure etc.;

d)

Improper Lighting

e)

Improper Ventilation

f)

Unsafe dress or Apparel;

g)

Hand Tools;

Lifting Equipment The use of mechanical lifting devices are becoming increasingly important in many types of operations to maintain the safety of such equipment and to avoid accidents, mechanical requirements are quite detailed and technical, and non compliance therefore leads to hazards Cranes. Derricks and hoists may be cause of accidents due to mechanical failure or unsafe operating practice. Frequent periodic inspection and maintenance of such parts as chain, wire ropes,

© PMI, NTPC

75

gears, clutches, brakes, bearings, and other fundamental elements may constitute a vital part of efficient performance.

ELECTRICAL HAZARDS --

Today almost every industry is power driven. It constituents the prime source of running of an industry. It is a servant of man, when kept under control, but it is a destroyer of life and property if not utilized properly.

--

In India, the normal lighting or house circuit operators on 20 volts supply. Industrial Voltage frequently extend from 440 volts to the transmission voltages .For purposes of safety precautions, these voltages may be considered high voltages although up to 440 volts are considered to be intermediate.

--

The effect or the severity of electric shock depends upon the rate of current flow (amperes) and the duration of the flow current. It has been found that the most serious pathway is that which crosses in the direction of the upper part of the body, such as arm to arm or arm to foot.. The amount of current through and body depends on the voltages to which the person is exposed and also the resistance of the person. The resistance changes under varying conditions, The Voltage is usually the only known criterion. As little as 0.05 ampere may cause a fatal shock, Dry skin offers a certain amount of protection since it has a resistance of from 100,000 to 600,000 ohms. Wet skin is however, less resistance to the flow electricity, having a resistance of approximately 1.000 ohms To Cause an electric shock, the current must flow like water, it must have a place to enter the body and a place to leave; the ground is commonly one of these two places There are so many grounded objects in our plants that it is fair to assume that most There are so many grounded objects in our plants that is fair to assume that most employees are liable to be contacting a ground object for a large part of their working day.

© PMI, NTPC

76

A handle on a machine A metal-framed stool standing standing on a concrete floor. The floor itself- shoes are not capable of insulating Our feet from the concrete unless they were special shoes. --

All that is needed then is an exposed live conductor or a faulty piece of equipments and these are the ingredients for a fatality. Of course, it is possible to get a shock by connecting two life conductors at different voltages or two pieces of faulty equipment, but by far the most common cause of electric shock is through a ground connection.

--

This insistence on grounding non – current carrying metals parts is necessary because occasionally the insulation on a wire or a piece of equipment can faill, if this allows the wire to touch a piece of metal assumes the same voltage as the wire and can cause a shock. However, if the piece of metal is grounded, the current from the damaged wire flows away to ground and the human body, which is likely to be grounded, does not receive a shock as there is no voltage difference between the body and the metal.

--

This is all well and good for wires, which are protected by metallic sheaths but many cases, still exists where live conductors are exposed. Overhead power lines. Electric crane rails. Open- faced substation switchboards are all assumed to be safe because they are out of the reach of the workman. This is not completely true.

For example i)

A mobile crane with a long boom can accidentally contact a power lines or other overhead live conductor.

© PMI, NTPC

77

ii)

A man carrying or climbing an aluminum ladder can come in contact with overhead conductors.

iii)

A maintenance man working upon the roof of a plant can contact frame of the building and an overhead conductor.

iv)

Metal bars stored vertically in racks may accidentally touch overhead crane wires and electricute a man.

Voltage Its seriousness: Usually, When we think of lineman, we picture a man who is paid to do extremely hazardous job of climbing poles and cutting and splicing high voltage. Whether the weather is good or bad.

This work, even though

dangerous, can be performed safely and efficiently. if precautions and the necessary

safety

equipment

are adhered. We all realize that these high

voltages are dangerous, but the tragic part is that there are so many peoples who do not realise how dangerous the 220 V that we use everyday in our lives can be, if it is not treated respectfully. We read in the newspaper almost every week several cases where someone has been killed or seriously injured through handling faulty hooked up equipment or equipment that has been allowed to run disrepair, This is where the real danger of electricity lies .not the high voltaged that we know are dangerous but the lower voltage which we come into contact everyday and which many people regard as harmless. The way men are injured are: *

Using portable electric grinders

*

Using skill saws

*

Operating vibrating screens

*

Using electric drills while installing ovens.

*

Pipe filter repairing, spot welder

© PMI, NTPC

78

*

Steel erector working on crane pulled cable, which contact 3300 V wires.

Seriousness of Electrical Shocks The effect of severity of electrical accidents depends upon the pathway, the amount of current and duration of the flow of current, there are three effects of this passage of current : *

Burn

*

Asphyxiation

*

Heart

CHEMICAL HAZARDS The chemical industry today is gaining phenomenal importance. The usage of chemicals with the resultant hazards gases. Vapors and fumes, is one of the most dangerous industries and one in which it is most difficult to protect workers. The list of toxic gases. vapors and fumes is exhaustive. In view of zealous search for compounds for industrial use the number of consequently increasing. The effect of noxious gases are widely different: *

Simple asphyxiates, e.g. N2, Ch4, Co2 (Nitrogen gas, Methane gas Carbon dioxide)

*

Chemical asphyxiant, e.g., Co, H2S, HCN(Carbon monoxide, Hydrozen sulphide, Hydro cynanic acid.

*

Irritatnt gases, e.g., No2 F, HF, SO2, NH3 (Nitrogen dioxide or peroxide, fluorine, Hydrogen Flouride, Sulphur dioxide, Ammonia)

*

Organic metallic gases, e,g, ASH3 ( Arsenic hydride)

*

Inorganic metallic gases.

© PMI, NTPC

79

--

Gases of irritant ground are potent poison; however workman exposed to them are able to avoid fatalities. Unfortunately, with gases such as carbon monoxide and arseniureted hydrogen, we feel non – irritant, colorless and tasteless. Here the victim may be overcome without even suspecting the danger, It is however, important to realize that though one gaseous poison may be more toxic than another, a great rate of volatility may the less poisonous more dangerous.

--

Several toxic chemicals and fluids are found in industries using sulphuric acid, nitric acid, soda, chloride of lime. Chloride of phosphorous, sulphur chloride phospene, chloride of Zinc, chlorophorm, Carbon tetrachloride, nitrous chloride, nitroglycerine, iodine, bromide, artificial fertilizers, rubber, celluloid, coal, petroleum, distillates,. Tar and gas and coke- oven industries.

Each of these and numerous others utilize poisons in the

manufacturing process, with poisons as chief products and poisonous byproducts middle products and impurities. --

A Simple classification of hazardous chemicals may be made as follows:

*

Metallic dusts and fumes

*

Mineral dusts

*

Volatile liquids and solids

*

Gases

*

Others.

Hidden Hazards One is confronted with the question “ What are hidden hazards?” or “ What hazards are hidden”? It seems that the answer to this question upon each man’s knowledge. What may be hidden to one may be quite obvious to the other. Some

© PMI, NTPC

80

hazards remain hidden even to the most expert, until a tragedy occurs. Even when prolonged and intensive investigation may be needed to reveal the cause.

HARMFUL CONDITIONS --

To have a better classification of occupational diseases, a simple classification of harmful conditions may be made as follows *

Abnormalities of air pressure.

*

Abnormalities of temperature and humidity.

*

Dampness

*

Defective illumination

*

Excessive noise

*

Radiant energy:

*

--

X –rays Gamma Rays.

--

Radioactive substance

-

Ultraviolet rays

-

Infrared rays

-

Ultra high frequency radiations

Repeated motion and pressure: Vibration.

© PMI, NTPC

81

11. Protective Clothing & Equipment HEAD PRODUCTION --

The priorities in selection should be the ability to give the best protection as far as possible by using a standard type, than appearance (if men look silly in helmets. They are reluctant to wear them) and comfort. Heavy and badly balanced helmets, which tilt backwards and forwards should be avoided. The impact protection is provided in part by the material of which the shell is made but mainly by the harness, which maintains a space between the crown of wearer’s head and the shell so that a considerable amount of shock can be absorbed. Periodic inspection of helmets is important to see that hardness is not slack and sloppy and can still do its jobs effectively, and that there are no cracks in the shell or other signs of damage. Chinstraps are desirable for outside work, or where climbing is necessary. Periodic cleaning and disinfections are desirable and lengthen wear life.

EYE PROTECTION -

For general all- round protection, wearer acceptability, optical correctness, good visibility, relative freedom from misting up, long life and ease of dealing with the prescription lens problems spectacle type eye protection, properly fitted so that the lens remains close to the eye, and having side shields is supreme. Steel frames are sturdier and to be preferred, but in practice the more closely protection spectacles

approximate to those

provided by the optician. The readier people arer to wear them.

© PMI, NTPC

82

EAR PROTECTION -

Where the noise level is on the region of 90 to 120 decibes, then plugs or valves will be satisfactory. Plugs may be of soft rubber or plastic, sometimes even of wax-impregnated cotton or paper. To give adequate protection, they really need to be individually fitted. and tend to lose their effectiveness unless the wearer “remakes” the plug when it loses effectiveness because of movement in the ear canal which happens every time the jaw moves, Ear valves are inserted in the ear canal and will reduce the general noise level

while still allowing the wearer to hear

human speech, It is generally considered that a reduction of 20/30 decibes can be achieved by properly fitted or valves, -

Circumaural ear defenders, earmuffs or ear pads (they are roses under other names) can reduce the penetrative noise level by a maximum of about 50 decibes. The material of which they are made is important, because washability and disinfection are necessary, Two cup shaped devices fit over the whole of the ears, including the lobes and are pressed gently inwards by a spring loaded suspension band or clip joins the two together, They do not require individual fitting, but tend to be uncomfortable is hot locations.

BODY PROTECTION There are a number of board classification into the which body protection falls. Here they are: *

Protection against heat.

*

Protection where flammables are present.

*

Impervious and chemical protection clothing.

*

Radiation protection.

© PMI, NTPC

83

*

High Visibility clothing.

*

Protection against cold.

*

General protection.

-

Fussy garments, with flaps on pockets and prominent buttons, should be avoided. Simple garments need not be ugly (Consider the popular all – purpose. Plain white saree which is an important component of most women’s Wardrobe) and a belt.,securely stitched to the back of garment, is excusable where there is no moving machinery, and thus gain greater protection.

--

Fly fronts, which merely means covering buttons by a continuous strip of material. Zips or adhesive – on - contact fastenings are preferable to exposed buttons, and garments should be fully cut. It’s not recommended idea to give men boiler suits, for example, which are so skimped for material that the action of bending over almost splits the wearer in two. Ease of washability and even sterilization may be important factors, as also in nonmetallic or protected metallic, fasteners on garments, leggings etc. to be worn in very hot locations, There’s not much point in protecting a man from the effect of heat during his working time, then burning his fingers when he takes off his garments at the end of a shift. There should be adequate, but safe, asses to clothing worm beneath protective garments.

RESPIRATORY PROTECTION --

There are three classification of such protection. They are: -

*

Self – Contained breathing apparatus used where there is an oxygen deficient atmosphere and / or known or suspected high concentration of contaminant.

© PMI, NTPC

84

*

Canister respirators, for use where there is not an oxygen deficiency but a known low concentration of contaminant.

*

Dust respirators when the contaminant is restricted to particles of dust or some particulate smokes.

HAND PROTECTION Here is a run – down on the most commonly used types of glove:

Canvas Not as commonly used in India as in some other countries, but its use likely to increase. Light in weight. Protect against minor cuts, abrasions, dirt and,

if

canvas is doubled in thickness in required area, heat in the lower temperature ranges( not above about 200F)

Terrycloth Becoming more popular, perhaps because the loop and pile construction give some slight resistance to impact. Rarely for protection against cuts and abrasions. Good wear comfort.

PVC Very widely used, Often in applications for which it was not originally intended. Good Chemical resistance. As the polyvinyl chloride is supplied to a fabric lining. The kind of liner is important . \Synthetic fibre liners such as Terylene give added resistance to cuts and snags, but are less comfortable in wear. A soft pliable knitted cotton is comfortable and helps combat hand fatigue.

© PMI, NTPC

85

Rubber Unsupported have some uses in delicate handling operations, and with a fabric liner give some resistance to chemicals. Can by suitable surface treatment; be made to give very good gripping qualities.

Neoprene Very good where oils are handled, and low temperature.

Polythene Excellent where exceptional manual dexterity is needed; and where a high standard of hygiene must be maintained.

Leather Gives some impact protection, good cut and abrasion resistance and when reinforced protection against heavy materials with sharp edges. Suitably treated (thermo- leather) has high heat resistance, Good for welders, burners

and

material handlers subjecting gloves to rough usage.

Asbestos Won’t burn and gives some protection against heat when lined. Coated with aluminum, reflects high levels of radiant heat,

Nitrile Users like them because of their flexibility. Particularly good against hydrocarbons, they also have useful resistance to some acids cuts ad abrasion.

© PMI, NTPC

86

FOOT PROTECTION --

If floors are wet not because of the nature of the work carried on. A reasonably non – slip sole should be sought.

--

Where there is an electrical risk. Ideally, footwear used should be sewn, or bonded with adhesive, free from nails and use non- conductive materials .On the other hand, there may be a static hazards so that conductivity is needed to allow static to leak to earth.

© PMI, NTPC

87

12. Safety In The Movement Of Men And Materials The following paragraph gives the Means of access and method of lifting: --

--

Ladders *

They must in a safe condition.

*

They must be either secured or footed.

*

They must be on firm base

*

They must be at the proper slope – 1 ft out for every 4 ft. up.

Scaffolds **

Fixed Staging Proper base Uprights Vertical Rigid – cross-braced Putlogs- Maximum 5 ft. apart (1.5 20m)

**

Mobile Staging Height not to exceed 3.5 X shortest base Wheels locked or chocked.

© PMI, NTPC

88

**

Working Platform Boarded – 1.5 in (40mm) boards supported every 5 ft.(1.520m) No Overhang Handrails Toe boards

**

Means Of Access

Ladder extends 3 ft. 6 in. (1.070 m) above working platform.

Manual Lifting **

Handling Adopt the proper stance Keep the chin in Keep the back straight Take the correct grip Keep the arms into the body Adopt correct foot positions Make proper use of the body weight.

**

Facts of Lift Am I sure that it needs moving? DO I Know where to move it?

© PMI, NTPC

89

Do I Know the weight Do I Know how the weight is distributed? Do I need assistance Do I needed special equipment (cradle) Do I Know how to grip it?

Lifting Attachments: **

Slings Checks S.W.L. is greater than load to be lifted Select correct type and termination. Protect sling from sharp edges Check angle between slings –do not exceed 90 C Never shorten sling by Knotting.

**

Shackles Select correct type. Check S.W.L. Use matching pin.

**

Eye Bolts Select correct type Check S.W.L.

© PMI, NTPC

90

Fit correctly – collar mating with boss Remember vertical lift only for Dynamo type. **

Hooks Check for distortion Use safety catche or mouse hook. Check S.W.L. Ensure that rings or sling rides freely hook.

Lifting Machines: **

Lifting Tackle Secure block properly Use block to suit size and type or rope. Remember load on beam is weight being lifted plus effort. Do not touch return o rope near blocks when in motion.

**

Jacks Ensure sound level footing. Pack under as load is raised. When more than one jack is used ensure that the load is taken on both jacks by raising them simultaneously.

**

Winches Check the brake

© PMI, NTPC

91

Make sure that the winch is in the correct gear. if in doubt use slow speed gear. Make sure that the locking device provided to keep the pinion in position is properly applied Make sure that the handles are fully engaged and properly secured. Make sure when hoisting or hauling that the pawl is engaged with the rachet wheel. **

Mobile Carnes The state of the ground or floor i)

Slope

ii)

Load bearing capacity.

Correct type pressure Use of outriggers- Packing? Locking of springs or axles Appropriate loads radius indicator Correct setting of automatic load indicator Adequate clearance for the lifting and slewing. Ensure smooth movements. Check position of slinger. **

For Lift Trucks The state of the floor or ground

© PMI, NTPC

92

i)

Slope.

ii)

Load bearing capacity.

iii)

Evenness

Tyre pressure Spread the forks to suit the load Tilt the mast back when travelling Keep the forks lowered when travelling. Do not raise or lower the forks whilst travelling No passengers to be carried. Always park with the forks lowered.

PLANNING THE MOVEMENT OF PLANT . --

Preparing *

Ascertain the weight of the load and its route.

*

Remember to include the weight of **

The load

**

The tackle

**

The pull

When selecting lifting beam or anchorage. *

Select and inspect the appropriate lifting tackle

© PMI, NTPC

93

*

Use only shackles for securing and joining (NEVER) lashing or nuts and bolts)

*

See that rings, Eyes, Shackles are free to ride on the hook and on each other.

Lifting *

Take the weight of the load and halt- Check tackle and stability of load – then lift.

*

Never ride on the load.

*

Walk in ahead of load, when practicable, Clear the route of people and check for obstruction.

*

Lifting machinery and lifting tackle should never be left untended when the load is suspended.

Arriving *

Select and prepare reception area, stillage, Platform, truck, etc, in advance

*

Where practicable lower directly on to reception place. Move crane or reception place to suit.

*

Do not crush slings- lower load on to wooden packings –not bricks

•

Check stability of load before slacking off, check again before removing lifting tackle.

Noting •

Return all lifting gear to stores- avoid dragging through dirt, dust, oil, water etc.

© PMI, NTPC

94

*

Clean lifting tackle and grease if necessary.

LIFTING AND HANDLING --

Lifting realize to a great extent on the skillful use of the right muscles, and not on brute force, Study the average worker who with the best of intentions is eager to get a case on to a lorry. First he tests the weight, then he puts the strain on his arms. If this doesn’t immediately do the trick and he considers heavy lifting to be a trick – he will then throw his shoulder muscles into the effort. If still unable to lift the case, he will put his back chest and abdominal muscles into action, at the same time bracing the muscles of this thighs and legs .All this steady addition of accessory muscle action will be an unconscious act which if performed a number of times in succession, may gratify his ‘strong man’ opinion of himself, but will certainly bring on fatigue, strain and perhaps injury.

--

The principle of lifting having been explained to him, he realises that the leg and thigh are stronger than the back or abnormal ones and he makes these to the lifting instead, keeping the back erect, and the arms straight .He places the feet moderately wide apart to give good balance so that the body is not leaning to one side or the other, One foot is leading towards the direction to be taken and the body in facing square to the, load. With it held close to the body he straightens his legs and comes up gradually like a human elevator or lift.

--

Size up the job First, if it’s Too Big, Get Help. When a packing case or similar load has to the manhandled by at least two people, the help of a workmate of similar height and physique makes all the difference in reducing strain.

© PMI, NTPC

95

--

An excessive load may seriously strain even the trained and experienced person, if it approaches or exceeds fifty percent of the individual’s body weight; the risk of injury from possible losses of balance is a real one. Accidents caused by the dropping of a load on the feet – eight because of loss of balance or insecure grip – are frequent. It is a good policy to take a look first at the lifting area- clean up slippery or oily parts of the floor and remove anything likely to cause obstruction and subsequent disturbance of natural balance.

--

Work Together Rhythmic action eliminates tension in limbs and back muscles. When two persons are carrying a load over an appreciable distance, and one of them is forced to relax or change grip, he should give ample warning to the other, Lifting, Carrying. Lowering --- in unison…. prevents strain and any tendency for either person to overbalance.

--

Organize the work Proper organization can reduce the amount of lifting necessary and, in particular reduce the need to lift loads from the floor. Where severe strain can occur. Loads should be deposited (from lorries. Carnes, fork – lift trucks, etc) on to suitable platform at about waist height, from which they can be lifted with the least effort.

--

Jacking and Shoving Twisting the body –or to be more accurate abusing and straining arm, shoulder and back muscles – will get that case where it’s wanted But it may be the last a worker will move for a long time, perhaps for ten weeks or so, That ‘s how long a worker injured in weight lifting is often laid up.

© PMI, NTPC

96

Get help whenever necessary and push forward with the arms steadily and smoothly, back erect. --

Its Tough At The Top Stacking or piling at too high a level causes fatigue and serious strain. Don ‘t wait until the stack is so high that the load has to be jerked up and forward above head level. Get a pallet platform to stand on or something similarly firm and giving a comparable standing area – an essential for maintaining perfect balance - and stack only chest high with your elbows kept in to your sides. If the shape of the load makes it impossible to keep your elbows well in, then do not stack more than waist high.

--

Keep The Hands From Being Injured Splinters, nails jagged edges, all are hazards frequently and easily overlooked.

When putting down the load, make sure the hands and

fingers are free before dropping it ; above all, before attempting to a carry anything rough or jagged remember. Gloves in use are worth any amount in store. --

See that Protection Clothing in Worn When Needed Ensure that protective gloves, safety boots are always available and used when the loads to be

carried need them – safety boots

to prevent

dropped loads crushing the toes, protective clothing for the carrying of corrosive chemical containers, hot materials, etc. --

Use Mechanical Means It is impossible to specify the maximum loads which can be safely lifted by the persons generally. Discretion is often the better part of valour and the packing case opposite is certainly one that should not even be shifted, let along lilted, by hand, A hoist, portable crane, fork lift truck….. the choice

© PMI, NTPC

97

of mechanical lifts is a wide one. Weight is not the only deciding factor. A load may be comparatively light and yet be so unwidely or irregular in shape that a secure ha nd grip is difficult to maintain . Hand – hooks or similar aids can often be used on many loads. --

Never Allow Anyone To Carry blindly – Or Too Much High standards of supervision are important in all aspects of accident prevention. Charge – hands and foremen should be safety – minded and be able to recognize potential hazards. Inexperienced workers and young people cannot be assumed to know how to lift of handle loads safely and without strain, Train them in the right method, Where a person has to be persuaded to discontinue a practice to which he has become accustomed, explain the reason to him, Discourage misplace zeal, as well as the occasional exhibitionist who always wants to carry a bigger load then the next fellow.

Lifting Ability Lifting ability in an individual depends upon many factors—‘Know- how’ is the main one. Others Include tone, susceptibility to strain and general physical characteristics A small wiry person can for example sometimes lift and carry with greater ease than a big one. The ‘ heaviness ‘ of a load is a relative term dependent upon the individual’s skill and condition. --

Some Other Points To Remember *

Do not persist in attempting to lift a load, which causes a feeling of strain.

© PMI, NTPC

98

*

Do not stand holding a heavy weight; If delay is inevitable, put it down a bench or platform of suitable henight.

*

Do not change grip while carrying, rest the load on a ledge or other firm support then change.

*

Carrying a load under one arm and supported by the hip causes local strain.

*

A load can be carried on one shoulder, but remember, if it’s heavy get someone to put it there,

*

Slippery floors and obstruction in the lifting area are dangerous.

© PMI, NTPC

99

13. Safety In Construction The construction industry has just about the worst accident record in any country. For instance in U.K. and average of 250 workers are killed each year and 46000 accidents are reported. According to the Federation of Civil Engineering Contractors one in every 50 workers who comes into the industry on leaving school will be killed at work before reaching retirement age. A similar trend is observed in the Indian Construction Industry as well. The majority of all accidents are due to the human failings and despite the terrific increase of machi nes over the past twenty years, there has been no corresponding increase in the percentage of machine accidents. Due to these accidents, a lot of useful time is lost at the work site resulting in lower productivity. This paper deals with various safety measures to be observed in order to attain higher productivity in the construction Industry. Table given below gives the various reasons for accidents are construction site and their shares in the total number of accident expressed in percentage.

Causes

Shares in Percentage

1.

Falling persons

45%

2.

Falling Materials

14%

3.

Transport

14%

4.

Lifting Equipment

7%

5.

Excavation

7%

6.

Electricity

6%

7

Others

7%

© PMI, NTPC

100

The following paragraphs illustrate a few safety measures to the undertaken in order to attain higher productivity.

Scaffolding --

A scaffold for the purpose of the Regulations means “any temporarily provided structures on or from which persons perform work in connection with operations or works” or “means of access or agree for persons or materials to places where work is being performed. The materials used on all scaffolds should be in sound condition suitable for the purpose and free from patent defect. They should be created by a competent workman who is experienced in such work. All scaffolds should be inspected after erection before being used and also after they have been substantially altered, they must also be inspected at least once a week while they are in use. Timber used for scaffolding should be stripped of bark and not painted so that the defects are not hidden If a scaffold is left in an unsafe or incomplete condition so as to be dangerous, then a warning notice should be fixed from where it can be readily seen. Before erection the ground should be levelled and made compact so as to be firm enough to carry any load that will be imposed. Suitable sole plates should be provided preferably heavy bulk timber, railway sleepers are ideal. Standards should be upright and for ordinary purposes spaced at no greater distance than 6 or 7 feet i.e, about 2 meters apart, All joints of standards must be staggered if heavy loading is to be imposed, then it is advisable

to have

the scaffolding designed by an engineer who is

experienced in such design works. Ledgers should be fixed to standards used only for the load bearing couplers and should be in level and all joints should be staggered. The height between ledgers should not be greater than 6 to 7 feet i.e. about 2 meters.

© PMI, NTPC

101

Transoms should be fixed to the ledgers and maximum span of the board must not exceed 5 feet i.e 1.525 meters in the case of 1.5”X 9” – 38mm X 228 mm scaffold boards. It may well be better to reduce this span according to the loading. Scaffold boards must not overhang their bears by more than 4 times the thickness of the board. Guard rails and toe boards must be fixed to working platforms, The minimum height of a guard rail is 3 feet i.e 6.15mm and maximum should not exceed 3 feet 9 Inches i.e 1.14 Meters. The minimum width of a toe board should be 6” i.e. 152 mm The distance between toe board and guard rail should not exceed 2’. 6” i.e. 762 mm All scaffolds should be properly braced and tied

to the building- it is

essential the building is strong enough for this purpose. Scaffolding material when not in

use should be kept under good conditions . A

proper means of access should be provided to all working places. Pole ladder is commonly used of this purpose. The grain of timber ladders should be straightr and free from shakes and knots. The angle of the ladder should be1 in 4. One foot out to four feet up. They should be so fixed so as to prevent movement from top and bottom points of rest and extend at last 3’.6” i.e’ 1.07 meter above their appoint of rest. The fixing should be done in such a manner that it does not cause trip hazard . There should be a good hold on every rung and special care should be taken with the rung near to the ledger at the stepping of appoint. Under no circumstances should the lashing be around the rung. It should be around each of the stiles and carried from stile to stile so as to leave the rung completely unimpaired. -

Cantilever or job scaffolds etc, are the work of experts and great care should be taken, both in the design of these and also in choosing workman who are thoroughly trained and competent to erect this type of scaffolding.

© PMI, NTPC

102

One of the most common types of scaffolds is a mobile scaffold. Too any accidents are reported in using such scaffolds. Their height should not be more than three times their narrowest width at the base unless suitable means, such as outriggers or weights at the base, are provided. Wheels should be fixed in such a manner so as to prevent accidental displacement. Right angle couplers should be used for fixing uprighjts to ledgers. The only non- load bearing couplers should be those which help in fixing the bearers of the scaffold boards when put log flips are used. The same general principles with regard to guard rails, toe boards, width and span of boards etc. should be applied in the case of independent tide scaffolds. Mobile scaffolds should only be moved from the bottom and never whilst workers are on them.

Excavation Although in total not so many accidents occur in or around excavations as on scaffolds. When they do occur, they are usually quite serious. Infact approximately one in ten accidents in excavations are fatal. The depth of the trench is not necessarily the deciding factor with regards to the seriousness of the injury. A yard of earth weighs approximately one ton and falls of this size are all to often fatal to workers involved. Excavations should be properly shored or the sites should be battered to a safe angle if men are to work in them. Following are the common causes of collapse. *

Simple mechanical failure of the soil because it cannot support its own weight.

*

Breakdown of the strength of the soil by moisture – usually caused by heavy rain or frost.

*

© PMI, NTPC

Failure caused by vibration from the movement of vehicles nearby.

103

*

Failure due to the weight of loads placed near the edge of excavation,

*

Failure due to the variation in the nature of the soil, such as pockets of sand

*

Failure due to

excavating on or

near

the side of

previous

excavation. *

Failure due to the sides of excavations being struck by heavy loads such as pipes, when they are lowered into it.

Proper precautions such as shoring or cutting the ground back to its natural angle of repose, i.e. battering is necessary. Bearing and other supports should be created and dismantle under the direct supervision of a competent person. All struts and braces should be secured so as to prevent accidental displacement. Any excavation deeper than 4’6 “ i.e 1.37 meters should be inspected atleast once a day, when men are employed there.; if the excavation is deeper than 6.6” i.e. 2 meters , the exacavation should be inspected at the beginning of each shift, if explosives are

used then no one should work until a thorough

examination by a competent person has been done. --

Proper precautions should be taken to prevent people from falling into the excavations. Barriers of sufficient height should be fixed to prevent this type of accident. Life - rope and spigots are to be driven into the ground far away from the edge so as to have no adverse effect on the side of the trench. Care should be taken to prevent loose material such as rock or stone, etc, from falling into a trench on to the workers . If the excavation is likely to cause damage or collapse of nearby building then such building should be properly shored to prevent such damage. Proper precautions should be taken to prevent vehicles from over – running or over – turning into the trenches This

© PMI, NTPC

is usually done by fixing a proper

104

sign board. Proper bridges should be provided to enable workers to cross excavations safely but if the fall is greater than 6’6” i.e. .2 meters height then guard rail and toe boards should be provided . All excavations and the approaches should be well lit. Care should be taken to ensure than dangerous gases, dust and fumes are not allowed to collect in excavations

LIFTING --

Gin Wheels This is the simplest and the oldest appliance for the lifting operation. Safe working land must be clearly marked. It must be securely fixed and the pole to which it is fixed should be strong enough to carry the load in a fixed position so that it may not move .It should be remembered that the load imposed on the fixture is double that is plus a little to allow for fraction of the actual load being lifted.

--

Hoists Hoists are defined as lifting machines with a carriage, platform or cage the movement of which is restricted by a guide or guides. All points of a hoist way from which anyone can be struck weather by platform or counter weights must be property enclosed, The winches or other moving parts likely to cause injury should be guarded. Gates should be provided at every landing place and they should be kept closed except for the purpose of loading or unloading. Arrestor gear should be provided to prevent the cage or platfrom falling if there is a failure of the hoist, ropes or driving gear and these should be strong enough to hold when loaded. Over run steps should also be provided to prevent the platform or cage riding over the top of the runway mast. The control of hoist should be from one position at a time only, This applies weather controlled by rope, switch or a lever, if the driver of a hoist

© PMI, NTPC

105

cannot clearly see cage and platform at all points then proper arrangements should be for clear signals to be given to him whether visual or audible. In case of hoists carrying persons,

the cage should have gates and

should be made so as to prevent people from falling out or being trapped whilst hoist is in motion. They must also be made so as to prevent passengers from being struck by objects faling down the hoist way, An inter lock should be fitted so as to prevent hoist way gates from being opened gates unless the cage is at a handing and to prevent the cage from moving if all gates are not securely closed.

Cranes -

All cranes and their working gear and anchorages and fixing devices should be of good construction, of sound material of adequate strength and free from patent defect Cranes should be used only on firm and level ground , The safe working load should be shown at the varying radio – Chains and ropes should be properly secured to their control lavers should to remain in very operating position control levers should turns to remain in very devices and should be clearly marked according to the re – erection of crane and should be done by a component person and boot the driver All loads should be properly supported to prevent accidental displacement All loads should be properly to prevent slipping or accidental displacement. All loads should be vertically lifted and drag loading should never be used under any circumstances.

Cranes -

All cranes and their working gear and anchorages and fixing devices should be of good construction, of sound material, of adequate strength and free from patent defect. Cranes should be used only on firm and level ground. The safe working load should be shown at the varying radio-

© PMI, NTPC

106

chains and ropes should be properly secured to their drums at least two turns to remain in every operating position. As far as possible all control levers should have locking devices and should be clearly marked according to their purpose. The automatic safe leading indicators should be tested after erection and re-erection of a crane and should be done by a competent person and not by the driver. All loads should be properly supported to prevent slipping or accidental displacement. All loads should be vertically lifted and drag loading should never be used under any circumstances. All lifting gear should be of adequate strength , in sound condition and of good construction. Wire ropes used for lifting and lowering should not be used in visible broken wires exceed five percent of total. Lifting hooks should have a chip or other means to prevent displacement of load, unless a specially designed to prevent accidental displacement. Rot iron chains and slings should be regularly annulled every six months when ½” ie 13mm or less in diameter and once in fourteen months if the diameter is more.

Use of Electricity -

All electric circuits should be installed and maintained only by component electricians. Proper earthing should be provided. In view of the nature of the work, the installations and switchgear need to be frequently inspected by a competent person. All transformers should be as close as possible to the incoming source of supply. All leads should properly insulated. The apparatus should be connected to the system by proper connections; under no circumstance should loose wires be pushed into sockets or held in position by matches. Hand Lamps should be so as to prevent from them becoming live and the bulbs should be protected so that they are not easily damaged or become a source of danger if they are broken.

© PMI, NTPC

107

14.

Safe Working Practices In Thermal Power Stations

GENERAL SAFETY RULES --

Before working on any machinery or equipment you should know about the following.

*

Where are its starting and stopping controls?

*

How to operate?

*

What are the precautions for the safe operation?

*

What personal protective equipment is to be used while working on this machine.

--

When you are issued personal protective equipment for the use in the particular working conditions, you must use them e.g. goggles for eye protection, helmet for head protection. Gloves for hand protection, Apron for body protection etc.

--

You should keep your work area clean. Do not spill oil on floor.

--

There should be no horseplay on shop floor. You should not tease others or distract the attention of fellow workers.

--

When you have completed a job, never leave your tools lying about. You should keep your in their proper place, otherwise they may cause injury to your fellow employees.

--

Give your suggestions for accident prevention and contract Industrial Safety Officer for safety problems.

© PMI, NTPC

108

SAFETY INSTRUCTIONS DURING MAINTENANCE --

When you go for the any repairs to some action, you must know the hazards in that sections required protective equipment for the wearing in these conditions.

--

You should take required safety precautions while working in that section.

--

Never start work on any pipeline or electric line till a permit has been issued, line has been isolated and tag has been placed at control switch showing that it is under permit ‘Not to be operated’.

--

You should always wear head protection while going for maintenance jobs.

--

You should carry all the required tolls for the job in bag and after completion, do not leave any tools lying around.

--

You should never start machinery or equipment without proper guard. Never consider a job completed till you have fitted the required guard.

--

Never leave a machine running without guard even while checking.

--

If you have removed any floor plated or pit covers fro repairs to machinery, you must replace back after completion of work is in progress, you must put up some barrier etc. so that others con not reach up to hazard.

SAFETY INSTRUCTIONS IN USE OF ELECTRICITY --

Whenever you go to attend electric defects, you must have a permit to work on line and see that line isolated. Use a main switch lock out device.

--

Every machine or electrical equipment must be properly earthed.

--

Use fuse wires of proper amperage according to load on the line.

© PMI, NTPC

109

--

Do not make temporary connections with lose wire-hanging wires around; if at all it has to be made, see that the wire is not lying on floor or is causing a tripping hazard.

--

Do not make loose connections. Do not insert naked wires into sockets. You must use a proper plug for each equipment with earth connections.

--

While working with portable tools, check for the worn out wires, loose connections or broken plug and if there is any defect get it rectified. Do not try to rectify electrical defects yourself, get the help of an electrician.

--

Never use metallic ladders in electric work or near the electrical equipment.

--

Do not leave broken plugs, sockets, and switches and worn out cables as it is; get them changed.

SAFETY INSTRUCTIONS IN OPERATIONS --

You should clearly understand and follow the instructions from U.C.B.

--

In case of an emergency do not panic, keep your mind cool and do the job safely.

--

If you any abnormality in functioning of equipment, inform U.C.B. immediately.

--

For operating hot valves, handling and cleaning of oil guns, you must use asbestos hand gloves.

--

You should not check burner flame with bare eyes, always view it through a glass preferably oiler man’s glasses.

© PMI, NTPC

110

SAFETY INSTRUCTIONS DURING CRANE OPERATION & RIGGING --

When lifting any load you must the safe working load of the crane. Never lift excessive load than the marked SWL capacity.

--

The loading hook should be in the center of the load lifted. Never drag the load with crane to bring it under the loading hook.

--

When a load is being lifted only one man should give signals, which should be followed by crane operator attentively.

--

Before lifting a load make sure that there are no kinks in chain or in wire of the crane or the signals being used, never lift the load with a sudden jerk.

--

When lifting a load with a chain pulley block you should also see that the anchor can stand the load being lifted. There are chances that anchorage may not be strong enough to stand the load up to lifting capacity of the chain pulley block.

--

The Crane Operators should: *

Never use a crane which is under repair.

*

Check all the control before starting the work.

*

Never use more than two controls at a time.

*

Check before moving that the slinging is alright by lifting the load about a foot from ground.

*

Never leave any work piece or tool laying on the crane or trolley while moving load from one place to another.

*

Never stand under the load being lifted.

© PMI, NTPC

111

SAFETY INSRUCTIONS FOR WELDING --

Always close the cylinder valve while carrying from the one place to another.

--

In case of leakage from gas cylinder immediately inform the foreman and use a mask while handling a leaking cylinder.

--

Keep the cylinder away from the naked flame and never lubricate its valve or other fittings.

--

For lighting the welding torch flame do not use a matchstick, always light with a friction lighter.

--

While welding you must use goggles, hand shield, head protection, body and feet protection against sparks etc.

--

As far as possible use a side screen for the welding so that the eyes of other people are not affected, welder’s helpers should also use the same protective equipment as being used by the welder.

--

The electric welders should not make loose connections for the supply to transformers. Electrical supply line must be connected by the electrician only at the work place.

SAFETY INSTRUCTIONS FOR MANUAL LIFTING, STACKING & CARRYING --

Never lift load beyond capacity, ask for the help.

--

When lifting pointed articles always wear gloves.

--

Before lifting a load, see for surroundingsthat there are no obstacles in way by which you have to carry the load.

© PMI, NTPC

112

--

Never bend your back while lifting a load and keep the load closer to your body. When lifting the load, place your right foot forward by the load to be lifted, bend your legs at knees, keep the back straight, chin up and lift with the muscles of your arms and legs with a firm grip. Never put strain on your back by bending.

--

While carrying a long rod or ladder etc, you should always keep the farther end of the rod up so that it may not hit some other workers.

--

While carrying load in a trolley: *

Never over load the trolley.

*

Never load it so high that you cannot see the pathway for obstacles or where you are carrying it.

*

Always push the trolley instead of pulling.

*

On a slope, take the help from some one if you cannot control its speed.

--

Always place the load on a level ground and in the required location.

--

If the ground is not level place the load on wooden planks etc, and check that the stack will not fall down.

--

While stacking, stack up to safe height so that it does not fall. Break the lines i n the stacking similar shaped articles as done in case of making walls with bricks.

--

When stacking round objects, always place stoppers at ends in lowest rung so that these cannot move outwards.

SAFETY INSTRUCTIONS FOR USE HAND TOLLS --

Always use the correct tool required for the each job.

© PMI, NTPC

113

--

Do not use a hammer, file screwdriver etc, with a broken slippery or loose handle; replace such handles and then only use.

--

Tools with broken or mesh roomed heads should not be used. These should be dressed or if cannot be rectified should be discarded.

--

Worn out or opened out spanners may slip, never use them. Spanners of proper size should be used for each job. Never use a spanner with packing or a leverage.

--

While using wrenches, apply pulling effort, never push it.

--

Never adopt wrong uses of hand tools e.g. *

Using a spanner in place of hammer.

*

Using pliers in place of a hammer.

*

Using a chisel in place of a screwdriver.

*

Using a screwdriver for the opening boxes.

*

Such practices damage tools and also cause accidents.

While using portable power tools, check for broken plugs, worn out or loose cords, earthing connections etc. if defective get it rectified and then only use it.

© PMI, NTPC

114

15. Permit To Work System A permit to work is printed from and issued to employees before they may work on specified items of plant. The objective of this practice is to make it safe for the employees to work and the permit in his guarantee of safety. However the following must be made clear time and again to the person obtaining permits. *

For his own safety be must ensure that he does not work on equipment for which a permit is necessary until it has been issued.

*

If he is drawing permit he should read carefully to make sure that he knows just which plant is declared safe. If he has any doubts he must to the engineer issuing the permit.

*

Sometimes he will be expected to work with a number of other people on an item of plant. In such case, one person will draw the permit for the whole job. The permit to work will be kept available for the inspection in workshop as long as it remains in force. He must read the permit before starting the work and if it is a long job taking more than one day or shift, he must check it at start of each succeeding day or shift.

*

All copies of a permit to work (PTW) must be singed when they are issued or cancelled.

*

PTW must not be singed expect in the presence of the engineer issuing or canceling it.

*

On PTW, recipient will be required to sign a statement that he has completed the work before PTW is cancelled.

© PMI, NTPC

115

*

PTW must be cleared by the person singing for receipt. Only in case of mechanical permits to work, It is permissible for a person to clear permit, Other than the person who received the permit; but in this case the person singing for the clearance must at least to the a supervisor.

*

All competent persons (notified as such) give their to the clearance in a very important statement returning the PTW. This is statement certifies the completion of work and that the work area has been cleared of tools / tackles and men and all safety guards replaced. These persons will then be responsible for any lapses in this regard.

STEPS / ARRANGEMENTS WHILE ISSUING PTW *

Expect in case of emergency, permits to work should be issued only against the presentation of an isolation request, describing the isolation required, from maintenance department. Person presenting themselves to collect PTW, should be fully familiar with the job and details of works to be done so that isolation request and permits can be matched.

*

All copies of PTW must be singed both at receipt and at clearance

*

Receipt and clearance signatures must be made only presence of S.C.C./ Unit in charge.

*

Permits to work should be issued between specified hours for overnight request and at 2 hrs notice should be given at all other times. For convenience PTW’s an engineer should be available in the permit office during later part of the day.

*

PTW’s should be signed for clearance by the person who signed for receipt. Where this is not possible and in case of mechanical permits only, person singing for clearance must at least be a supervisor.

© PMI, NTPC

116

*

Whenever a job is permanently transferred from to one person to another, the permit should be cancelled and reissued, the amendment of a PTW is prohibited.

*

When changed in isolation becomes necessary, the permit shall be cancelled and reissued. Work on medium/low voltage equipments should be done when they are dead. At least two isolations should be in service in case of electrical permit.

*

In case of emergency, when Shift Charge Engineer initiates the action, an emergency job card should be made available from within the operation department giving details of the work to be done to avoid breaking down of record system.

*

Do not operate - Caution boards should be put on items under PTW.

RECEIPT OF PERMIT TO WORK *

It is the responsibility of all persons on site to ensure that they do not start work on equipments for which a PTW is necessary until the PTW has been issued. While drawing the PTW, the recipient should read the PTW carefully and make sure that he knows just what plant is declared safe. If in doubt it should be clarified. All employees to work on job must check that a permit to work is in force before commencing work on any job for which permit is necessary. This check must be made at the start of each day or shift and before starting of any new job,

*

As far as possible, an individual will draw the PTW for specific jobs to which they have been allocated. It is the responsibility of Shift Charge Engineer issuing the PTW to ensure that the person is familiar with the nature and extent of the work to be done.

*

When it is unavoidable, a person of higher rank can also draw the permit; but it will be the responsibility of this person to ensure that the men under

© PMI, NTPC

117

his charge are acquainted with the plant to be worked on, the work to be done and limitations imposed by safety requirements. *

When a person is required to work along with a number of other individuals, the PTW for the whole job should be read personally by everyone before they start the work.

*

In case of electrical permits, it is not permissible for supervisors to draw permits unless they perform the work themselves or supervise it continuously and directly.

© PMI, NTPC

118

16. An Executive’s Role In Safety INRODUCTION --

Of all the responsibilities of an Executive, it is said, number one is that the he is responsible for the getting out production. Since he is responsible for getting out production from to his employees, anything which interfaces with the expected production has to be his immediate concern.

--

Production does not always means the actual making of some article. It may mean handling of material or the delivery of finished to the consumer. It may mean the maintenance of building or equipment, operation of boilers, engine etc, What ever the job may be, it is an essential part of the business and any interference with its functioning is considered as an interference with production .To prevent any such interference is therefore, a part of the executive’s responsibility.

--

The loss of employee’s time because of illness is one source if interference with production. Many an illness, however may be the result of unsafe practices eg. wearing improper or insufficient clothes or footwear or working in areas not properly protected. But the greatest interference is almost always the result of accidents. They may result in injury to persons or damage to machines or equipment and sometimes may mean even both. Obviously, it is executive’s responsibility to stop source interference with his production.

--

One might have come across the question:” I know what my men should do to avoid accidents, but how do I guide them to do it?” I have told them to do it what more do you expect of me? When and executive talks this way, he very likely does associate accident prevention with the prevention of production errors.

© PMI, NTPC

119

--

Whereas the same Executive may have the answer for the production troubles, e.g., if he wants some planks board out and workman says, “I will drill them out,” planks get board out. If he wants a packing case assembled with screws and the workman says I will use nails ‘the case is assembled’. Why there never seems any doubt in an executive’s mind as to how to act in cases of this kind, because he recognizes the fact that the production might suffer and it is his responsibility

to get production.

Nevertheless it is also his responsibility to get out production without accidents or injuries. It is true of course, that an accident and an injury do not happen every time something is done in an improper manner, But it is also true that if improper methods are permitted to continue, accidents will happen and both injuries and production losses might result.

ACCIDENT PREVENTION AND EFFICIENCY --

The causes of production troubles are the same as the causes of accidents; Time is lost because material is not piled properly. Time is lost because areas are blocked with boxes or material that should not be there. Time is lost because the wrong kind of a wrench or other tool is used. And only sometimes these improper actions cause injuries. But every time they do occur, operating efficiency suffers and there is an interference with the job of getting out production. Obviously, therefore, an executive’s concern is not only the elimination of accidents that result in personal injury, but accidents that result in loss of time, damage to equipment or products and interference with planned procedures. Nobody ever saw a work schedule or a blue line print that said ‘Stop time for an Accident’. There is always a right way of doing a job. If jobs are properly planned and are done as they are supposed to be done, we will not have accidents. That in short, is all that is required of executive in the prevention of the accidents and to get people to do their jobs in the way they should be done.

© PMI, NTPC

120

--

As the executive controls the working personnel, he has the responsibility of telling his men how the job should be done safely and why “the short cuts” should be avoided since employees do not remember everything that they are told, the second step is to follow up instructions by observations to see that they are complied with. If this is supplemented by devoting a few minutes each day to search out unsafe practices and caution the employees, the mistakes will be avoided as soon as they are observed. This is the most important step to accident prevention.

WHY INVESTIGATE THOROUGHLY When an accident has happened, the executive usually investigates only such causes that require medical attendance. Many a time the cause of an accident is given as “carelessness”. This is a meaningless expression, unless an executive is able to

determine at what step the individual concerned was careless. It

should be ensured that investigation should be made as soon as possible after the accidents. Delay always causes the details to be forgotten. If possible, the employees involved should be interviewed. The impression should not be give that the executive is trying to fix the blame. In interviewing employees, facts and not opinions as to the cause should be sought. In determining the facts the executive should himself ask what he would have the same circumstances. What did the employees do that was unusual? Or was there any unsafe condition? The final question after the thorough investigation should be, why did the employee do what he did? Discovering unsafe practice and learning “ why” of action will help in discovering similar traits in other workers, The “ whitewash” in reviewing accidents cause employees to expect protection, slows analysis, hides contributing factors and prevents supervisory action that prevents accidents.

© PMI, NTPC

121

CORRECTIVE ACTION -

This is the most important step of an executive’s responsibilities. It is the process of getting things done and the process remains the same whether we are talking about the production troubles or the prevention of accidents. Generally speaking, there are four methods available for applying corrective measure: *

We can correct a hazard by mechanical means, can eliminate the conditions or change the operation that creates the hazards. We can repair the broken defective part or we can put a guard on the dangerous machine part.

*

We can eliminate the cause by assigning people to other kinds of work. This applies more in relations to accident – prone workers. It has been found that probability of an accident can be reduced by a change in the environment

*

The corrective action can be applied through disciplinary measures. This method of approach may be tried only when other methods have failed.

*

We can prevent accidents through the method of instruction and appeal, which is the most effective way to get results.

--

If an executive finds that the employee is not doing what he told him to do, he should try find out the reason why? It may be that in some instance it is because of absentmindedness, nerve recklessness or a willful disregard of instructions. Yet in other cases, the executive, may find that the employee has failed to understand the instructions or he is not convinced that the method he is using is not safe. It may also be that the physical deficiency of an individual prevents him

from following the instructions. If he is able

to find out the reason why, he has a clue as to what he must do to

© PMI, NTPC

122

overcome the non-compliance. Many a time the fault rests entirely with the executive himself. If instructions are not being followed are, he can ask himself: *

Have I exhibited an active interest in accident prevention?

*

Have I given safety instructions with the same degree of enthusiasm and determination as production instructions?

*

Have I pointed out to the men the importance of their job to the finished product and how improper methods can seriously interfere with the completion of a project?

*

Have I previously ignored violation of the same instructions that I am now trying to enforce?

*

Have I been guilty to do the same thing that I am now trying to correct others from doing?

*

Have I given others an opportunity to express themselves?

*

Have I been impartial?

*

Am I fair in what I am asking?

© PMI, NTPC

123

17. Factories Act 1948 Factories Act, 1948 was implemented by the Government of India to consolidate and amend the Law regulating labour in factories. Basically, it is a socio economic law enacted for ensuring safety, health and welfare of the employees working in the factories. The summary of this Law is given here. For details, the provisions of Factories Act 1948 should be seen. Following safety provisions are the major provisions of this law: -

General Duties Employer (Sec.7A) The Employer must ensure as far as reasonably practical safety, health and welfare of the workers. It includes sharing

of information, training and

supervision.

General Duties of Manufactures /Designer / Imported Supplier (Sec.7B) The manufactures / Designer / imported Supplier must ensure safety in design /construction and supply of adequate information on safety. They should follow the standard of the country from where being imported , if they are superior to India. Otherwise follow the Indian Standard.

Fencing of Machinery (Sec. 21) This is to provide fencing of all moving and dangerous parts shall be provided and kept in position.

Work on or near machinery in motion (Sec.22) This is to ensure that the only specially trained adult male workers wearing tight fitting clothing are permitted. A Register of such persons should be maintained.

© PMI, NTPC

124

Employment of Young persons on dangerous machine (Sec. 23) Only those young persons who had received sufficient training in if such work should be kept under adequate supervision are allowed to work under this Section.

Striking gear and devices for cutting of Power (Sec-24) The provisions related to mechanical and electrical isolation should be provided, maintained a nd used for cutting of power in emergencies.

Self – acting machines (Sec- 25) Traversing part of a self – acting machines are not to be allowed to reach 45 cm, from any fixed structure to prevent any possible injury.

Casing of any new machinery (Sec. 26) Set screws, bolt or key, gears, which does not require frequent adjustment, should be completely encased. No one sell or let on hire or procure the machine without above said encasing.

Prohibition of employment of women or children near cotton openers (Sec. 27) Women and children are prohibited to work on or near the cotton openings.

Hoists and lifts (Sec –28) It should have safe construction, safety maintained and examined by a competent person at east once every six months. Safe working load (SWL) shall be marked and overloading not allowed, hoist or lift used for the carrying persons shall be fitted with a gate for the access, which should not open except at the races.

© PMI, NTPC

125

Lifting machines, chains, ropes and lifting tackles (Sec, 29) Safe construction, safe maintenance, examination once in 12 months, safe working load to be marked and not to be over –loaded are the main characters of this Section. Safe passage should be provided for employees to work on or near the wheel tracks.

Revolving machinery (Sec . 30) Measures should be undertaken to prevent over- speeding.

Pressure plant (Sec 31) In the pressure vessels, pressure should not be exceeded to the safe working pressure. The pressure vessels should be examined regularly as per State Factory Rules.

Floors, Stairs and means of access ( Sec 32) All floors, stairs and means of access should be free from all obstructions. They should be fully safe.

Pits, Sumps, Opening in floor, etc (Sec-33) Pits, Sumps, Openings in floor, etc should be either covered or fenced.

Excessive weights (Sec. 34) The employees should not be allowed to carry excessive weight to their capacities.

Protection of eyes (Sec. 35) Effective means like screens or suitable goggles should be provided to prevent risk to eyes from particles/ excessive light.

© PMI, NTPC

126

Precautions against dangerous fumes, gases, etc. (Sec 36) No person should to be allowed in confined space having risk till the dangerous vapor / gas / dust has been removed within permissible limit and tested by a competent person. Proper protective equipments should be provided for the employees going inside such space.

Precautions regarding the use of portable electric light (Sec 36A) No light / electrical appliance beyond 24 volts should be used in confined space unless adequate safety provisions are provided. For inflammable equipments, flameproof equipment should be used.

Explosive or inflammable dust, gas, etc. (Sec. 37) Explosive or inflammable dust or gas plant should be effectively enclosed. Measures should to taken to prevent ignition.

Precautions in case of Fire (Sec 38) Safe means of escape, its familiarization to the workers and necessary fire fighting facilities should be ensured.

Power to require specifications of detective parts or tests of stability (Sec39) Government empowers itself to ask drawing specification of defective parts, etc.

Safety of building and machines ( Sec. 40 & 40 A) Under the provisions of this section, all the building and equipments, should be safe and should be maintained safe.

© PMI, NTPC

127

Appointment of Safety Officer (Sec 40B) Every factory appointing more than 1,000 workers should employ at least one safety officer. The number of safety officers, their qualification and conditions of service, should be as described in State Factory Rules.

Power to make Rules to supplement this Chapter (Sec. 41) This provides special power to State Government for making other Safety Rules. In May 1987, the President of India gave his assent to the amendments to the Factories Act which provides for stringent measures for ensuring industrial safety, especially in hazardous industries. The amendments seek to enlarge the scope and applicability of the Act to matters relating to the protection of the environment on the premise that the activity carried on inside the factory would have a pote ntial to adversely affect the surrounding environment .We take a look at the following important provisions which have been inserted through the amendments: -

Safety Policy (Sec. 7A /41 B) The new sections require declaration of a safety policy by the factory, which should be communicated to the workers. It should be a written statement with respect to the health and safety of workers, and the State Governments have been advised to notify all promises engaged in chemical processes as factories even though they may be employing only a couple of persons for the purpose of having a safety policy.

Site Appraisal Committee (Sec. 41A) A hazardous process has been defined, and 29 industries have been specified which involved hazardous processes. These industries before they are located in any particular area require appraisal of the conditions from the point of the view raw materials used, Intermediate or finished products, by products, wastes and

© PMI, NTPC

128

effluents produced by the manufacturing process. The amendment provides for the establishment of a Site Appraisal Committee by the State Government which will examine an application for the establishment of factory involving hazardous processes and make its recommendations.

Disclosure of Information (Sec. 41B) A factory carrying on hazardous process will have to disclose information on health hazards, and measures to overcome such hazards arising out of harmful exposure in the operations. Not only the workers employed in the factories are required to be informed, but also the local authority within whose jurisdiction the factory is situated, the general public in the vicinity of the factory and the Chief Inspector of Factories are also required to be informed of the hazards.

Medical Examination (Sec. 41C) Since exposure to dangerous substances can cause occupational diseases, the workers employed in hazardous process should be subjected to medical examination before they are employed in the process. They should also be examined periodically to detect any deterioration in health. The Act requires the occupier to maintain accurate and up to – date health records of workers employed in such hazardous processes. Further, such records should be made available to the workers, through some reasonable conditions may be prescribed. The first schedule has listed 29 industries in which hazards processes are carried out. For each type of process, there will be different

medical testes

and

examinations involved and these are to the be prescribed in the Rules. Hazardous industries are required to appoint persons with desired qualifications and experience in handling hazardous substances who are competent

to

supervise, such operations in the factories. Such a person will be responsible for guiding workers and ensuring safe working conditions in the plant. He will be expected to know about the hazardous properties of the materials being used or produced.

© PMI, NTPC

129

Government Inquiry (Sec. 41D) The Central Government may, in the event of the occurrence of an extraordinary situation involving a factory engaged in a hazardous process, appoint an Inquiry Committee to ensure into the standards of health and safety observed in the factory with a view to finding out the causes of any failure to neglect in the adoption of any measure or standards prescribed for the health and safety of the workers employed in the factory or the general public affected or likely to be affected, due to such failure or neglect for the prevention and recurrence of such extraordinary situations in future. Where the Central Government is satisfied that no standards of safety have been prescribed in respect of hazardous process or class of hazardous processes or where the standards prescribed are inadequate, it may direct the Director General of Factory Advise Service and Labour Institute, or any institution specialized in matters relating to standards of safety in hazardous process to lay down emergency standards for enforcement of suitable standards in respect of such hazardous processes.

Safety Committee (Sec .41G) In every factory carrying out a hazardous process, workers participation in safety management will be ensured by setting up a Safety Committee which will be required to promote co-operations between workers and managements for the safety and health conditions at work and also to review periodically the measures taken.

Right of Workers to warn about imminent danger (Sec. 41H) Workers can tell the management through the Safety Committee Members and also Inspector in case of imminent dangers. In such case, the Occupier shall take immediate remedial action.

© PMI, NTPC

130

Prohibit Work (Sec. 87A) If conditions in factory pose serious hazards by way of injury or death to the workers or the general public in the vicinity, the Occupier may be prohibited from employing any person in the factories till the hazards is removed. It shall be entitled to wages of stoppage of work. It shall be the duty of the Occupier to provide alternative employment, and the worker shall be entitled of stoppage of work.

Implementation of Factories Act The provisions of this Act are to be implemented by Inspectorate of Factories. They have power to investigate / enter any factory, ask for the registers, seize or take any copes of any document. Direct occupier to leave any thing / place undisturbed, take photos, record statements, etc. The prosecutions are to be filed by the Inspectorate of Factories only.

Punishments With the amendments in Factories Act, Punishment are very much enhanced. For general violations, provision of imprisonment of two years and / or penalty of Rs. 1 Lakh is there .For repeat violation, in some cases, imprisonment of three years / or penalty of Rs 2 Lakh can be there. However, for death, minimum fine shall be Rs. 25000/- and for severe injury, it shall be not less than Rs. 5,000. For repeat cases for death, it shall be Rs. 35,000/ - and severe injuries, it

shall be

Rs. 10,000/For violation of Sections 41B, 41 C & 41 H relating to compulsory disclosure of information, health records and imminent dangers- the punishment can be 7 years imprisonment and or fine of Rs 2 lakhs, while for its repetition, it can be up to 10 years’ imprisonment.

© PMI, NTPC

131

18. Indian Electricity Act & Rules The Indian Electricity Act of 1910 and Rules there under are as old as about eighty years. The Act was first framed in a most crude form called as Hawra Bridge Electricity Act 1902 at Calcutta. The same form was adopted and generalised then as Indian Electricity Act 1910 for uniformity all over Indian States and for control of electricity being the matter of high technology, and of paramount importance. The electricity was considered as commodity which required control from generation point to the utilisation point. The Indian Electricity Rules 1956 were framed later after same years. The Indian Electricity Act 1910 is devided into four parts, and the sections of which deal with following matters broadly.

Preliminary

Title, extent and commencement, definition of terms. (Section 1 & 2)

Licenses

Issue of licenses for supply of electricity in area of supply. (Section 3 to 11)

Works Sections 12 to 19. Supply Sections 19A to 27. Supply Licenses ( Protective Clauses

Sections 31 to 34

Administration and Rules

Section 35 to 38.

Criminal procedure

offences

and

Section 39 to 50. Section 51 to 58.

Supplementary I to XVII Schedules

© PMI, NTPC

132

Some of the relevant sections are Section 33 & 36 Appointments of Electrical Inspectors under Inspectorate wing of I.E. & L. Deptt. to carry inspections under I.E. Rules 1956 of all Electric Installations and investigate the causes of electric accidents, inquire into and report to Government.

Section 36A & 37

Appointment of Central Electricity Board for framing and or amendment of I.E. Rules under I.E. Act 1910.

Section 38

Appointment of members of Central Electricity Board, and further provisions.

Indian Electricity Act 1910 and Rules thereunder are therefore very much necessary for uniformity of working practices in standardisation of electric supply lines, appliances and in control of electricity as commodity.

The Electricity being the commodity and generated, transformer distributed and utilized, either through licensees or Electricity Boards other than Government, requires to be controlled for which I.E. Rules 1956 are framed. The non uniformity in control of electric commodity would cause chaos in consumers and supplies due to preferential treatments, standardisations of voltages and thereby appliances, apparatus.

The Electricity is also dangerous to human beings and proper if not used with proper safety measures or precautions hence I.E. Rules 1956 are framed under I.E. Act 1910, which are therefore to be followed scrupulously.

© PMI, NTPC

133

The Electrical Inspectorate under I.E. & L. Deptt. of Govt. of Maharashtra is responsible for application of I.E. Rules 1956 and the Safety is implemented by : Regular Periodical Inspection of Electrical Installation as required under rules 46 of I.E. Rules 1956, The recommendations are issued on consumers licensees, officers of electricity boards, to comply with I.E. Rules 1956. On severe Breach of I.E.

Rules

1956,

5(4)

orders

:

Means

compulsory

compliance

of

recommendations given by the officers of Gazetted rank within stipulated period, to be complied else prosecution may be launched and default punished in court of Law.

Investigation, of Non Fatal/Fatal electrical accidents carried out by an officer not below the rank of Gazette rank. The causes are found out ?or avoiding the mistakes in future. The defaulters are also prosecuted in court of Law. Repeitative

causes

when

noticed

are

communicated

to

concerned

Licensee/electricity board officials so as to take precautions to improve the electrical installations or change method of construction accordingly.

It would be of great interest to know how and what were causes and remidies for the causes of electrical accidents on safety point of view, so as to take precautions in future.

The causes mainly devided into following reasons : Non use of Standard Materials

The accidents have occurred to many industries due to use of deteriorated or cheap use of PVC Wires, apparatus, E.G.Cables, P.V.C. Wires used for Grinders, Blowers, defective Grinders, blowers etc.

© PMI, NTPC

134

*

Ignorance

If knowledge of electricity is not properly received by Wireman, Layman, the wrong connections e.q. green wire connected to phase causes fatal accidents Examples - 1. 2.

Fatal accidents to Carpenter at Malad. Fatal accidents to unknown at Nanda Dhup Indus. G.I

Bare wire for neutral if connected to wrong polarity will charge all metallic parts connected to it and cause fatal accidents. *

Overconfidence

If proper precaution while working on the dead lines are not taken to earth the same and if the overconfident person works on live portion which were supposed dead by him but are live receives electric shock. Examples are

- Testing of G.O.D. also testing of 440 volt terminals with 250 volt test lamps may lead to an accident.

*

Maintainence

Many a times preventive maintenance schedules are not followed. The Electric Installation became defective and old electric installation requires renovation. *

Supervision

Most of the industries run on electrical powers however the work of electrical nature are not supervised by a competent person or authorised person and thus workers meet with an electrical accident. Even if the supervisors competent authorised persons are available they lack in supervision due to negligence.

© PMI, NTPC

135

By looking at some of the above reasons cited above it would be almost necessary that above reasons could have been avoid had there : §

A proper use of standard materials.

§

Working of electric lines/apparatus is carried through Licensed Electric contractors

•

Working on live lines is avoided.

•

Proper preventative maintenance is carried.

•

All electrical work is supervised by authorised person.

However the fatal electrical accidents could be avoided generally by taking following precautions. •

Proper sizes of fuses if used or the circuit breakers of proper setting to breaker the circuit currents are used case of leakages.

•

Proper use of earthing.

•

Use of earth leakage circuit breakers.

The procedure adopted for prosecution for breach of I.E. Rule 1956 under I.E. Act 1910 is as follows :

The intimation of the Fatal Accident is to be given to the Electrical Inspector within 24 hour s. of its occurrence and report in form of Annexure XIII submitted within 48 hours him as required under Rule 44A of I.E.Rules 1956. The accident is investigated immediately and causes found out. If found necessary leakage is

© PMI, NTPC

136

decided by taking megger tests. The statement of Eye witnesses collected. 5(4) orders and Show causes notices under I.E. Rules 1956 served on to the defaulters and case is consulted with Public Prosecutor for filing in Court of Law. The result of the court is binding on defaulter.

Electrical Inspectorate thus observes safety of working of Electrical apparatus and equipments by carrying out Electrical inspections as per I.E. Rules 1956 under I.E. Act 1910, and finding out causes leading to fatal, non fatal electric accidents and advising Govt. on the same. The Inspectorate also deals in investigation of complaints, of various nature in electricity and giving proper advise to the concerned and deriding disputes between consumers and electric suppliers.

© PMI, NTPC

137

19. Gas Cylinder Rules 1981 And Static Static & Mobile Pressure Vessels (Unfired) Rules 1981 The Indian Explosives Act, 1984 is an Act to regulate the manufacture, possession, use, sale, transport and importation of explosives. Four important Rules framed under this Act are the following: •

The Explosives Rules, 1983.

•

The Gas Cylinder Rules, 1981.

•

The Static & Mobile Pressure Vessels (Unfired) Rules, 19

•

Carbide of Calcium Rules, 1937.

This talk is being restricted to Rules mentioned at item number 2 & 3 above. Whereas Gas Cylinder Rules, 1981 came into effect 24-2-1981 and superseded the earlier Gas Cylinder Rules, 1940. Static & Mobile Pressure Vessels (Unfired) Rules, 1981 were entire a new legislation and came into effect throughout the country 4-2-1981.

The object of both these Rules is to provide a comprehensive for regulating through-out the country :

-

Possession, delivery, dispatch, handling, examination a testing of gas cylinders and

-

Construction fitment, storage, loading, transport, licensing and inspections etc. of pressure vessels for composed and liquefied gases.

© PMI, NTPC

138

These Rules impose certain restrictions relating to the above items. The main objective, however, is to protect the public against their dangerous nature by regulating all dealings connected therewith.

THE GAS CYLINDER RULES, 1981 This is quite a comprehensive enactment. However, only some more important provisions are discussed below. The handling of compressed gas cylinders is relatively safe today, because of engineering improvement and standardization of cylinders and components. It may be helpful to remember that compressed gas cylinders are not designed for temperatures exceeding 130°F. Gas cylinders designed and approved for filling with a particular gas shall not be used for filling with any other gas, unless specific approval) is obtained from the Chief Controller of Explosives. Any cylinder which fails to pass periodic examination or test, or which loses in its tare weight by over 5% or which for any other defect is found to be unsafe for use shall be destroyed in a manner whereby the pieces cannot again be joined together by welding or otherwise to form a cylinder.

Some Important Definitions

These are Compressed Gas, Dissolved Gas, Liquefiable Gas, Flammable Gas, Permanent Gas, High Pressure liquefiable Gas, Critical Temperature, Filling Temperature & Filling Ratio. A gas cylinder or cylinder means any closed metal container intended for the storage and transport of compressed gas, designed not to be fitted to a but not exceeding 1000 litres. All these definitions are given under Rule 2 of these Rules, which should be studied to understand these Rules fully.

All cylinders and valves are to be constructed in accordance with approved design and specifications. Manufacturers of the cylinders have to obtain test and inspection certificates from the inspecting authority prior 10 their use. All gas

© PMI, NTPC

139

cylinders have to undergo various tests after manufacture, according to their working, make and design. Some of the tests are Heat treatment. Hydraulic test, Leakage test and Pursting test.

Valves fitted to gas cylinders have to comply with various ISI specifications, depending upon whether these are used for industrial gases, medical gases, used for breathing apparatuses or for tilling liquefied petroleum gas.

Safety relief devices for cylinders manufactured in India must conform to ISI specifications. In respect of cylinders containing obnoxious or poisonous gases, safety relief devices are not to be provided.

The material, design and construction of safety devices shall be such that there will be no significant change in the functioning of these devices and no deterioration occurs due to service conditions.

Every gas cylinder and valve should be clearly and permanent marked by stamping, engraving or similar process. The information provided by the markings include the specifications to which the cylinder is made, its working and test pressure, tare weight and water capacity. Such markings stamped should not be tampered with.

The name of the gas and that of the filling party shall form the label on every cylinder together with a warning as prescribed in Rule.

Repairing, painting or altering the colour of the cylinders at the consumers' and are strictly prohibited.

Persons under 18 years of the age or in a state of intoxic should not be employed for loading, unloading or transport of any compressed gas cylinders.

© PMI, NTPC

140

Handling & Transporting Cylinders

Adequate care should be taken in their handling viz – •

They should not be dropped or allowed to fall upon one another.

•

LPG Cylinders and cylinders containing liquefiable gas shall always be kept in an upright position and shall so placed that they cannot be knocked over.

•

Cylinders which are used in horizontal position shall so secured that they cannot roll.

•

Trolleys and cradles of adequate strength shall be used whilst moving cylinders.

•

Cylinders with any compressed gas shall not be transported by a bicycle or any other two-wheeled mechanically propelled vehicle.

•

Whilst transporting them, they shall be adequately secured to prevent their falling off the vehicles and being subjected to rough handling.

•

Cylinders of compressed gases shall not be transported along with any other article of a highly inflammable or corrosive nature.

•

Cylinders containing flammable gases shall not be transported along with cylinders containing any other type of compressed gas.

•

Cylinders containing toxic or corrosive gases shall not be transported along with foodstuffs.

© PMI, NTPC

141

•

Lifting magnets cannot be employed for loading, unloading of compressed gas cylinders. Where such operations are carried out by means of a crane or a fork lift truck, a proper cradle with chains or wire rope slings shall be employed.

No person shall deliver or despatch any cylinder filled with compressed gas to any other person who is no the holder of a license to possess such cylinders, unless he is exempted from obtaining a license under the Rules.

Protection Of Valves During Transport

Every cylinder containing compressed gas shall have its valve securely closed and protected against damages and leakages. Valves fitted to the cylinders containing LPG and highly toxic gases such as Phosgene, HCN, Carbon Monoxide, Hydrogen Sulphide, Chlorine, Fluorine, Sulphur Dioxide etc. shall be provided with a security nut or gas-tight metal caps or covers on the outlet, to act as a secondary means of safeguard and against gas leaks.

Storage of Cylinders

Cylinders shall be stored in a cool, dry, well-ventilated placed under cover, away from boilers, open flames, steam pipes or any other potential source of heat. The place of storage shall be easily accessible. The storage room or shed shall be of fire resistant construction. For sheds storing non-flammable gases, beams, rafters, columns, windows and doors may be of wood. Cylinders containing flammable gases shall be kept separated from each other and Rom cylinders containing other types of gases by an adequate distance (greater than 1m) or by a suitable perdition wall. Empty Cylinders shall be segregated from filled ones and care shall be taken that all valves are tightly shut. The storage shed shall be adequately ventilated near the ground level and near or in the roof. In case the storage shed is used for storing LPG cylinders, the ventilators shall be provided

© PMI, NTPC

142

with two thickness of copper or other non-corroding metal wire gauze of mesh not less than 11 to the linear centimeter. Distances between 0 metres to 15 metres shall be kept clear at all times between any building, public place, public road or any adjoining property which may be built upon and the storage shed used for the storage of LPG cylinders of upto 100 kg. to over 30,000 kg. Such a storage shed shall not be situated under any staircase or near other-entrances to or exits from the rest of the building or other buildings. A shed used for storage of LPG Cylinders shall be surrounded by a suitable fence to prevent unauthorized persons from having access to the shed. A minimum of two portable foam type/chemical type fire extinguishers of 9 kg. each shall be kept at a convenient location for immediate use in the event of any fire. In premises for filling and storing flammable gases in cylinders, all electric meters distribution boards, fuses lamps etc. shall be of flameproof construction conforming IS:2148. The storage shed shall be in the charge of a competent person.

General Precautions

Gas cylinders should not be placed where they might become parts of an electric current circuit. Where cylinders are used near to or in conjunction with electric welding, precautions should be taken against accidental grounding of compressed gas cylinders and allowing them to be burnt by electric welding etc. Cylinders shall not be used as rollers supports or any purpose other than for which they are intent. In moving cylinders, it is important that they sho uld not be subjected upto abnormal mechanical shocks, which might damage the cylinders and the valves. Care should be taken to ensure that cylinders are not dropped or allowed to strike against each other violently. Valve protection caps shall never be used for lifting cylinders from one position to another. Before raising a cylinder provided with cap from horizontal to vertical position., it should be ensured that the cap is properly placed hard and tight and the cylinder raised by grasping the cap.

© PMI, NTPC

143

Testing Of Cylinders

All cylinders have to be tested at periodic intervals. Any cylinder which fails to pass such tests or which loses its tare weight by over 5% or which for any other reason is found to be unsafe shall be destroyed after defacing all the markings.

Filling & Possession

The Rules provide for obtaining licenses for filling and possession of gas cylinders. There are certain restrictions on filling of cylinders. Prior approval of the Chief Controller of Explosives has to be obtained of specifications and plans of premises proposed to be licensed. Rule 52 prescribes the limits in capacities or numbers of cylinders of different types of gases such as LPG, flammable but non-toxic, non-flammable non-toxic, toxic and acetylene gas, beyond which it would be necessary to take out a license to possess such cylinders. License fees vary from Rs.100 to Rs.300 per year for storing different type of gas cylinders beyond the capacities given in Rule 52 as well as for their import and filling. The working pressure in any cylinder filled with a permanent gas shall not exceed two-thirds of its test pressure. Cylinders filled with liquefiable gases shall not be filled in excess of filling ratios specified in IS:3710.

Accidents & Inquiries

Rules provide for notices of accidents to be given to the Chief Controller of Explosives, Nagpur by an express telegram to be followed within 24 hours by a letter giving full particulars of the occurrence and to the Officer-in-charge of the nearest Police Station by the quickest route. If inquiries into the accident are to be conducted by a magistrate, these shall be in the presence of the Chief Controller or one of his nominated officers.

© PMI, NTPC

144

THE STATIC & MOBILE PRESSURE VESSELS (UNFIRED) RULES, 1981 This is another comprehensive piece of safety legislation. Only a very few very important provisions, however, are dealt with below, since it is not possible to cover the entire Rules, in a talk of this nature.

GENERAL

Some Important Definitions

These are given in Rule 2 of these Rules. A pressure vessel for the purpose of these Rules is defined as any closed metal container of whatever shape, intended for storage and transport of any compressed gas which is subjected to internal pressure and of which water capacity exceeds one thousand litres etc. This does not include containers wherein steam or other vapour is, or intended to be, heated by the application of fire or the products of combustion or by electrical means. The definition also excludes heat exchangers, (evaporators, air receivers, steam type digesters,) steam type sterilizers, autoclaves, (reactors, caloritiers and pressure piping components,) such as separators or strainers. Any such vessel, which form a part of a processing plant is also excluded, other than the storage vessel connected with the plant. Rule 2 may be referred to definitions of competent persons, design pressure, water capacity, flammable gas, corrosion etc.

Certain restrictions have been imposed by these Rules on the fillings, manufacture, delivery and despatch of compressed gassed in a vessel. No person can fill any compressed gas in a vessel or transport a vessel filled with compressed gas unless it has been manufactured in accordance with certain does approved by the Chief Controller. No person can deliver or despatch any

© PMI, NTPC

145

compressed gas in a vessel to any person other than the holder of a storage license.

These is prohibition on carrying out repairs to a vessel unless these are approved by the Chief Controller.

Before using any new vessel or before re-filling any vessel which has been made gas free, air contained in the vessel should be purged with an inert gas. In both these cases, the purged gas should be vented off only after taking adequate precautions to prevent its ignition

Persons under the age of 18 years or in a state of intoxicate should not be employed for the loading, unloading or transport of any such vessel containing compressed gases.

Persons should not smoke and matches, fires and such materials capable of causing ignition are not allowed near any place where compressed gas is stored, handled or transported in a vessel.

No person on enter a vessel used for the storage of a toxic or corrosive gas, unless he is adequately protected by suitable clothing, gas masks etc.

CONSTRUCTION & FITMENT OF PRESSURE VESSELS Design Code Vessels should be designed for the most severe combinations of operating conditions, which may be experienced jn normal operations, where vessels are subject to alternate heating and cooling, provision should be made in the design to permit expansion or contraction to avoid excessive thermal stresses.

© PMI, NTPC

146

Vessels should be designed, constructed and tested in accordance with IS 2825 or a code/ standard approved by the Chief Controller.

Vessels subject to corrosion should have a corrosion allowance to cover the total deterioration expected during the life of the equipment.

Design Pressure

The design pressure of a vessel should not be less than: •

The vapour pressure of the gas in the vessel at 55°C for liquefiable gases, it trip vessel is insulated, the vapour pressure of the gas corresponding to the maximum temperature. that the gas is likely to attain shall be used.

•

The developed pressure of the gas in the vessel at 55°C for permanent gases

Materials used for insulating vessels shall be approved by the Chief Controller. The insulation shall be covered with a metal jacket of minimum 3 mm thickness, which is weather tight.

Filling Capacity And Filling Pressure •

No vessel shall be filled with any permanent gas in excess of its design pressure

•

In case of liquefiable gases, the maximum amount shall be limbed to the filling density of the gas, and also dependent upon whether the vessel is insulated or uninsulated.

© PMI, NTPC

147

Markings

Every vessel shall have a name plate giving details regarding the manufacturers name construction code. Official stamp of the Inspector, design pressure, hydrostatic test pressure water capacity etc.

Painting

Vessels should be painted externally to prevent corrosion and should have a reflecting surface.

Fittings

Each vessel shall be provided with the following fittings:

Pressure relief valves connected to vapour space, emergency shut-off valves liquid level gauging device, Temperature indicator. Drains and at least one pressure gauge connected to vapour space.

Pressure Relief Valves −

Every vessel should have two or more pressure relieving devices, with a shut-off valve between each device and the vessel. The arrangement of the shut-off valve shall be such as to afford full required capacity flow through at least one of the safety relief valves. Safety relief valves shall have direct communication with the vapour space of the vessel.

−

The relief valves should be spring-loaded set to start discharging at a pressure not exceeding 110% of the design pressure and should have a relieving capacity such that the maximum pressure in the vessel does not exceed 120% of the design pressure.

© PMI, NTPC

148

−

Relief valves should be tested not less than once ,,a year and a record of such tests maintained.

*

Emergency shut-off valves

All liquid and vapour connections on vessels except those for relief valves, should have an emergency shut off valves, such an excess flow valve, an automatically operated valve or remotely controlled valve. This shall be of a type, which shall not fail. *

Liquid level gauging device

Every vessel should be equipped with a liquid level gauging device. In addition, it should be equipped with a fixed maximum level indicating device.

All vessels shall be hydraulically tested by a competent person at the test pressure valve at intervals of not more than 5 years; for corrosive or toxic gases this test shall be done at an interval of two years. The competent person carrying out this test shall issue a certificate of test.

STORAGE *

All vessels shall be installed entirely above ground, in the open.

*

Vessels shall not be installed one above the other.

*

The number of storage vessels in on installation shall not exceed six. These shall be located such that their longitudnal axes are parallel to each other. The top surface of the vessels in the installation shall be on the same plane.

© PMI, NTPC

149

*

Vessels installed with their dished ends facing each other shall have screen walls between them.

*

No vessel shall be located within the dyked are of petroleum or other flammable liquid storages.

LOCATION OF VESSELS •

Minimum safety distances between vessels and built up area for flammable, corrosive and toxic gases are given in one table, whereas the second table gives the minimum safety distances for non-toxic gases. The minimum distances between the vessels are also prescribed. Refer Rule 22 for this purpose. These distances vary from 5 m to 30 m between vessels and buildings etc. and between 1 m and the diameter of the larger vessel as the minimum distances between vessels.

•

Every vessel shall be supported on well designed foundations.

•

The storage area consisting of vessels, loading and unloading facilities etc. shall be enclosed by an industrial type of fence, at least 2 m high with at least two exits, the gates of such exits shall open outwards and shall not be self-locking.

•

An area of 3 m around the vessel shall be kept free from ignitable materials such as weeds and long dry grass.

•

These Rules further prescribe arrangements for fire protection, loading and unloading facilities, transfer operations, Electrical apparatuses and installations, lighting of storage and operating areas, display of a permanent notice, regarding prohibiting smoking and use of naked lights, earthing provisions etc.

© PMI, NTPC

150

•

A certificate of safety in the proforma given in these Rules and signed by a competent person shall be furnished to the licensing authority before any vessel is used for storage or whenever any addition or alteration to the installation or vessel foundation is carried out.

LICENSING A license has to be obtained for storage of any compressed gas in any vessel. Prior approval of the Chief Controller of specifications and plans of the vessels and premises proposed to be licensed is necessary. The license is liable to be suspended or cancelled if at any time the continuance of the license fee for storing compresses gases in an installations varies from Rs. 1,000/- to Rs. 10,000/- per year. The license fee for transporting compressed gas by a vehicle is Rs. 1,000/- per year.

ACCIDENTS & INQUIRIES Notice of an accident has to be given to the Chief Controller by means of an express telegram, followed by a detailed letter within 24 hours of the occurrence. Inquiries into accidents shall be conducted by a magistrate in the presence the Chief Controller or one of his nominated officers. Inquires into accidents shall be normally held in the open court but it may be held in camera if the Central Government so directs,

© PMI, NTPC

151

20. Legal Aspects Of Safety Under Other Acts WORKMEN'S COMPENSATION ACT, 1923 Definition of Disablement −

"Partial disablement" (Sec. 2g) means, where the disablement is of a temporary nature, such disablement as reduces the earning capacity of a workman in any employment in which he was engaged at the time of accident resulting in the disablement, and, where the disablement is of a permanent nature, such disablement as reduces his earning capacity in every employment which he was capable of undertaking at that time; provided that every injury specified (in part II of schedule I) shall be deemed to result in permanent partial disablement;

−

"Total disablement" (Sec. 2.1) means such disablement, whether of a temporary or permanent nature, as incapacitates a workman for all work which he was capable of performing at the time of the accident resulting in such disablement: (provided that permanent total disablement shall be deemed to result from every injury specified in Part I of schedule I or from any combination of injuries specified in Part II thereof where the aggregate percentage of the loss of earning capacity, as specified in the said Part II against those injuries, amounts to one hundred per cent or more).

Employer's Liability for Compensation (Sec. 3) : If personal injury is caused to a workman by accident arising out of and in the course of his employment, his employer shall be liable to pay compensation is in accordance with the provisions of this Chapter : Provided that the employer shall not be so liable ; −

in respect of any injury which does not result in the total or partial

© PMI, NTPC

152

disablement of the workman for a period exceeding (three) days ; −

in respect of any (injury, not resulting in death caused by) an accident which is directly attributable to; •

the workman having been at the time thereof under the Influence of drink of drugs, or

•

the willful removal or disregard by the workman to an order expressly given, or to a rule expressly framed, for the purpose of securing the safety of workmen, or

-

The willful removal or disregard by the workman of any safety guard or other device which he knew to have been provided for the purpose of securing the safety of workmen.

Amount of compensation (Sec. 4): Subject to the provisions of this Act, the amount of compensation shall be as namely : −

Where death results from the injury and the deceased workman has been in receipt of monthly wages falling within limits shown in the first column of Schedule IV - the amount shown against such limits in the second column thereof ;

−

Where permanent total disablement results from the injury and the injured workman has been in receipt of monthly wages falling within limits shown in the first column of Schedule IV -the amount shown against such limits in the third column thereof).

−

Where permanent partial disablement results form the injury ;

© PMI, NTPC

153

a)

in the case of an injury specified in (Part II of Schedule I) such percentage of the compensation which would have been payable in the case of permanent total disablement as is specified therein as being the percentage of the loss of earning capacity caused by that injury, and

b)

in the case of an injury not specified in Schedule I, such percentage of the compensation payable in the case of permanent total disablement as is proportionate to the loss of earning capacity permanently caused by the injury;

c)

Explanation : Where more injuries than one are caused by the same accident, the amount of compensation payable under this head shall be aggregated but not so in any case as to exceed the amount which would have been payable if permanent total disablement had resulted from the injuries ;

Where temporary disablement, whether total or partial results from the injury and the injured workman has been in receipt of monthly wages falling within limits shown in the first column of Schedule IV -a half monthly payment of the sum shown against such limits in the fourth column thereof, payable on the sixteenth day ;

*

from the date of the disablement, where such disablement, lasts for a period of twenty-eight days or more, or

*

after the expiry of a waiting period of three days from the date of the disablement, where such disablement lasts for a period of less than twenty-eight days.

© PMI, NTPC

154

and, thereafter, half-monthly 'during the disablement or during a period of five years, whichever period is shorter:

© PMI, NTPC

155

Provided that :

a)

There shall be deducted from any lump sum or half-monthly payments to which the workman is entitled the amount of any payment or allowance which the workman has received from the employer by way of compensation during the period of disablement prior to the receipt of such lump sum or of the first half-monthly payment, as the case may be; and

b)

No half-monthly payments shall be any case exceed the amount, if any, by which half the amount of the monthly wages of the workman before the accident exceeds half the amount of such wages which he is earning after the accident.

Explanation

Any payment or allowance which the workman has received from the employer towards his medical treatment shall not be deemed to be a payment or allowance received by him by way of compensation within the meaning of clause (a) of the provision.

On the ceasing of the disablement before the date on which any half-monthly payment falls due, there shall be payable in respect of that half-monthly a sum proportionate to the duration of the disablement in that half-month.

Wages and Related Matters

Compensation is to be awarded under the Workmen's Compensation Act on the basis of "wages' of the injured employee. When the question is what compensation is to be awarded to an employee who has been injured, the term 'wages' is to be interpreted in the light of the definition given in Section 2(n) of the Workmen's Compensation Act, and not in the light of the definition given in the

© PMI, NTPC

156

payment of wages act. The words privilege or benefit, in the definition of wages, in the Workmen's Compensation Act includes the benefit of free accommodation. It is, therefore, clear that the monetary value of such accommodation, since free accommodation is capable of being estimated in money, when provided free to an applicant falls within the term 'wages' for the purpose of assessing the amount of compensation (B.M. & G. Engineering Factory V, Bahadur Singh, AIR 1955 ALL 182 (DB).,

Compensation to be Paid When Due and Penalty for Default : −

Compensation under Section 4 shall be paid as soon as it falls due.

−

In cases where the employer does not accept the liability for compensation to the extent claimed, he shall be bound to make provisional payment based on the extent of liability which he accepts, and such payment shall be deposited with the Commissioner or made to the workman, as the case may be, without prejudice to the right of the workman to make any further claim.

−

Where any employer is in default in paying the Compensation due under this Act within one month from the date it fell due, the Commissioner may direct that in addition to the amount of the arrears, simple interest at the rate of six per cent per annum on the amount due together with, if in the opinion of the Commissioner there is no justification for the delay, a further sum not exceeding fifty per cent of such amount shall be recovered from the employer by way of penalty.

EMPLOYEE'S STATE INSURANCE ACT, 1948 Definitions

© PMI, NTPC

157

-

"Employment injury" means a personal injury to an employee caused by accident or an occupational disease a ring out of and in the course of his employment in a factory or establishment to which this Act applies, which injury

or

occupational

disease

would

entitle

such

employee

to

compensation under the Workmen's Compensation Act, 1923, if he were a workmen within the meaning of the said act.

"Employee" means any person employed for wages in or in connection with the work of a factory or establishment to which this act applies and -

*

who is directly employed by the principal employer on any work, incidental or preliminary to or connected with the work of the factory or establishment, whether such work is done by the employee in the factory or establishment or elsewhere ; or

*

who is employed by or through an immediate employer on the premises of the factory or establishment or under the supervision of the principal employer or his agent on work which is ordinarily part of the work of the factory or establishment or which .is preliminary to the work carried out in or incidental to the purpose of the factory or establishment; or

*

whose services are temporarily lent or let on hire to the principal employer by the person with whom the person whose services are so lent or let on hire has entered in to a contract of service ;

but does not include -

*

any member of the Indian Naval, Military or Air Force ; or

© PMI, NTPC

158

*

any person employed on a remuneration which in the aggregate exceeds four hundred rupees a month.

Disablement benefit (Sec. 51) Subject to the provisions of this Act and the regulations, if any :

*

a person who sustains temporary disablement for not less than three days (excluding the day of accident), shall be entitled to periodical payment for the period of such disablement in accordance with the provisions of the First Schedule ;

*

a person who sustains permanent disablement, whether total or partial, shall be entitled to periodical payment for such disablement in accordance with the provisions of the First Schedule

*

Provided that where permanent disablement, whether total or partial, has been assessed provisionally for a limited period or finally, the benefit provided under this clause shall be payable for that limited period or, as the case may be, for life.

Who will be the beneficiary (Sec. 52)

*

Subject to the provisions of this act, and the regulations, if any, disablement benefit shall be payable;

**

to a person who sustains temporary disablement, during the period of such disablement ;

**

to a person who sustains permanent partial disablement, during his life;

© PMI, NTPC

159

**

to a person who sustains permanent total disablement, during his life; and

**

to a person in all cases of disablement not falling, under subclauses a, b, or c of this sub-section, as may be provided in the regulation.

Disablement benefit shall be paid on the scale and subject to the condition specified in this behalf in the Second Schedule.

© PMI, NTPC

160

21. Health Hazards Of Hazardous Chemicals INTRODUCTION Every progressive employer must have a policy for Health and Safety at work which states that, "the Company will do all that is reasonably practicable to establish and maintain a healthy and safe workplace for all its employees and to conduct its activities in an environmentally responsible manner to ensure the Health and Safety of people in the vicinity of its operations"

This aims to provide guidance on the identification of potential health hazards associated with the use of chemicals either raw materials or other substances used in processes.

CLASSIFICATION OF HAZARDS ASSOCIATED WITH THE HANDLING AND USE OF RAW MATERIALS This is concerned specifically with the identification of potential hazards associated with the handling and use of chemicals used as either raw materials or for some other purpose in concern operations.

The hazards discussed relate principally to health and safety issues but consideration is given to the environmental aspects associated with the handling and disposal of spillages of such materials. The latter will obviously be directly related to the potential hazards associated with the substances concerned and handling and disposal of materials into the environment will need to be done in the light of these properties and the need to comply with local legislation.

© PMI, NTPC

161

The hazards associated with the handling and use of chemical substances used as raw materials can be considered under four major categories ; −

Hazards to health

−

Fire/Explosion hazards

−

Reactivity hazards

−

Environmental hazards

Potentially hazardous substances can be encountered in many physical forms, which in themselves can have a major impact on the types of health and/or safety hazards associated with the materials. The major physical forms are:solids, liquids, gases, dusts, fumes, mists and vapours.

HAZARDS TO HEALTH -

Definitions of Health Hazards

Health effects can be LOCAL (e.g. acid burns to skin) or SYSTEMIC (e.g. when a chemical is absorbed and transported through the body to a target organ). These can be further separated into ACUTE and CHRONIC effects.

A convenient way to categories HEALTH EFFECTS caused by exposure to chemicals is as follows:

*

NUISANCE

a nuisance effect can arise for example from a dust which though it poses no immediate risk to health but can result in unpleasant and stressful working conditions.

© PMI, NTPC

162

*

IRRITANT

a non corrosive substance which through immediate, prolonged or repeated contact with skin can cause inflammation.

*

ALLERGEN

a substance to which some individuals can become

censitised.

When the

allergy

is

established, minute quantities of the substance can precipitate an attack involving for example skin, eyes or nasal/respiratory system,

*

CORROSIVE

a substance (usually an acid or alkali) which destroys living tissues on contact.

*

TOXIC

there are many definitions of toxicity. For example, the U.K. packaging and Labelling Regulations use two levels - TOXIC and VERY TOXIC. These are defined as substance which if they are inhaled, ingested, or penetrate the skin may involve respectively serious or extremely serious acute or chronic effects and even death. Such a definition could include CARCINOGENS or TERATOGENS.

*

Types of Exposure

Exposure to chemicals can be considered as BRIEF or PROLONGED defined as follows :

BRIEF EXPOSURE

short duration exposure (from seconds to hours in total) if the chemical is exposed to skin or by inhalation. For ingestion acute exposure implies a single dose.

© PMI, NTPC

163

PROLONGED EXPOSURE

for inhalation or skin exposure prolonged exposure

covers

continuous

or

repeated

exposures of days, months, or years. For ingestion it can mean repeated doses of chemical for days, months or years.

*

Routes of Entry/Exposure

The principal routes of entry/exposure encountered in industrial processes are :-

*

Inhalation

*

Skin or Eye Contact

*

Mucous Membrane Contact

*

Ingestion

Of these inhalation and skin contact are far and away the most important in industry.

*

Individual Susceptibility

In some circumstances (particularly related to toxic effects associated with chemicals) it is important to identify employees that might be particularly susceptible to a specific chemical hazard. Apart from the obvious cases of allergy/ hypersensitivity to a chemical, due regard should be paid to others factors such as −

Age

−

Sex

© PMI, NTPC

164

−

Pregnancy

−

Smoking

−

Alcohol intake

−

General state of health.

ENVIRONMENTAL HAZARDS Though this is principally concerned with health and safety aspects associated with the use of hazardous chemicals, it is important to consider the effects of materials when they are discharged from the factory site either via sewers, as solid wastes or as gaseous emissions When discharges occur either as a result of processing or from spillages etc., the ultimate effects of the materials on the environment (whether it be sewage treatment processes, or general ecological effects) need to be considered and the discharges of such materials should conform to any pertinent local legislation which prevails.

IDENTIFICATION OF HAZARDS Intrinsic in the process of identification of hazards associated with the use of chemicals is an appreciation of the potential ways in which workers could be exposed to the chemicals in question. In general, exposure of workers to chemicals can occur during any of the following operations : −

Storage

−

Handling

−

Processing/Packaging

© PMI, NTPC

165

A hazard identification system must therefore consider each of these operations as a potential source of exposure to chemicals. In addition any potential environmental problems associated with the disposal from site of these chemicals should be considered.

-

Fundamental Information needed for Hazard Identification

A prerequisite for the recognition of potential hazards associated with the use of chemicals on a particular site requires that there should be a complete record of all materials present on site. This should include raw materials,

intermediates,

by-products,

waste

materials,

significant

contaminants, and finished products. Such a record must be kept accurately and updated on a regular basis.

Having established an inventory of the mate rials used on site, the next step is to obtain fundamental information about each, essential to the evaluation of its potential hazards. The information required can be considered to fall into the following categories : •

Details of its composition and physical properties.

•

Health hazards

•

Fire/Explosion Hazards

•

Environmental Hazards.

•

Any specific reactions which may lead to any of the above hazards

•

Legislative information

•

Process date

•

Safe handling procedures

•

Emergency procedures.

© PMI, NTPC

166

Health Hazards

Information should be obtained on the potential hazards and toxicology associated with each chemical. Where appropriate this should include information on principal target body sites such as skin, eyes, respiratory system or mouth/ digestive system and the effects of acute and prolonged exposure should be defined along with levels of exposure at which these effects will occur. Systematic effects should define the route(s) of exposure at which effects may occur. Such information will then permit a general health hazard statement about the chemical to be made in terms of whether it is nuisance, instant, corrosive, allergenic or toxic. This should normally be available from the manufacturer or supplier of the literature but if not then work may need to be conducted to obtain in the necessary basic information.

Environmental Hazards

The fundamental information required to assess the environmental hazards of releasing a chemical to the environment includes : −

is the material biodegradable

−

is the material toxic in the environment

−

will the material cruse problems in sewers (e.g. solvents) or at sewage treatment works (e.g. acids or biocides)

−

as a consequence of the above hazards it may be necessary to dispose of the material as a toxic/hazardous waste.

−

what limits have been set for exhaust air and, waste water discharges.

© PMI, NTPC

167

Any Specific Reactions Which May Lead To Hazards

As explained earlier it is difficult to cover comprehensively all reactions which may lead to hazards. There are however two major categories of reaction which should always be considered : −

Heat generating or explosive reactions involving oxidising or reducing agents.

−

Production of toxic materials/gases.

Legislative Information

It is essential that any current local legislative information relating to compounds or groups of compounds is known. This should include employee exposure legislation (e.g. control limits, MAK's TLV's etc. as appropriate) or legislation relating to the disposal of the material.

In addition, many countries have employee exposure levels which are recommended but not legally binding. These, however, should always be observed. Much of the relevant employee exposure legislation is summarised in Occupational Exposure Limits for Airborne Toxic Substances by the International Labour Organisation (ILO) Where no legislation exists in a country it may be prudent to use that operating in other countries (e.g. ACGIH in USA).

Process Data

Exposure to a substance can result from any of three major sources of exposure: −

escapes/problems during storage

−

handling of raw materials.

© PMI, NTPC

168

−

escapes of material during processing and/or packaging.

It is therefore essential to examine each of these particular facts of production in order to establish whether there is potential for exposure to a raw material. Potential hazards will depend greatly on the physical form of the raw material (e.g. solids giving rise to dust exposure or dust explosion problems, gases being present at unacceptably high levels in workroom air, or liquids evaporating to give unacceptable levels of substance in workroom air).

One particularly useful method of collating information on the hazards associated with using chemicals is to produce it in standardised format on Data Sheets. Ideally, all chemicals used should have information set out in this way and a centralised store of such Data Sheets should be readily accessible to all company operations. Hazard Date Sheets specimen are given in Appendix.

Suggested Procedures for Hazard Identification

Having collated all the necessary information relating to the potential hazards associated with using a particular substance the next step is to apply this to the particular situation prevailing at a factory operation. This is best done by doing an initial assessment of potential hazards associated with the material in question, and linking this to a Raw Material and Process Audit.

The Occupational Health Raw material and Process Audit (A) asks questions relating to the hazards to health associated with the material in question. If no hazards are identified then it is concluded that the material is acceptable from a health point of vie'./ and no problems should ensue. If however, potential problems occur then it asks whether or not there are points of release during normal or abnormal processing and whether employee exposure is possible. If these are negative, then again it is concluded that the material is acceptable. If they are affirmative and exposure could be replaced by a safer one. Then this

© PMI, NTPC

169

case arises the new material must then be reconsidered. It there is no acceptable substitute, then GD must be consulted for assessment and control of the health hazards associated with using the material.

RESUME OF TOTAL HAZARD IDENTIFICATION SYSTEM The identification of potential problems associated with the use of chemicals in any process can readily be broken down into 5 main stages as follows : •

Collection and collation of data relating to the health and safety aspects of the chemical in question.

•

Performance of initial assessment of the hazards associated with the process(es) in .question.

•

Where required, a Raw Material and Process Audit for both Occupational Health and Safety, should be done.

•

Where potential hazards have been identified) and chemicals cannot be replaced by potentially safer materials reference should &e made to Data Sheets for advice.

Assessment and Control of Employee Exposure and Prevention of Fires and Explosions Associated with Hazardous Substances.

Finally And Most Importantly

Periodic re-assessment based on the above scheme should take place to ensure that no changes in processes or raw materials unwittingly introduce a potentially hazardous situation; or that new toxicological data alters the regulatory view of the material leading to reassessment of risk associated with its use.

© PMI, NTPC

170

22. The Indian Boilers Act 1923 And Rules HISTORY OF BOILERS History of steam boilers is very old and of ancient time. As far as the early history of boiler goes, it is stated that the one boiler was recovered from the ruins of pompoli, which was of bronze metal. In 1030, B.C. Horo's engine was first recorded as doing the work. In 1720, the boilers were manufactured from copper plates and rivets and the pressure was (maximum 30 Ibs. PSI. In the middle of 18th Century, boilers) were manufactured from steel plate. In 1840, the wellknown Lanchashire boiler as manufactured and still in our Country, the Lanchashire boilers are largely used. In U.K. 18 million Lanchashire boilers are in use.

THE BOILER ACT IN ENGLAND Till the nineteenth Century, there was no inspection technique, and hence there used to be lot of accidents in U.K. and as a result of large number of accidents, a select committee was appointed by the Majesty Queen Victoria to suggest ways and means to avoid explosion. However, this committee could not be implemented anything in absence legislation. In 1850 in Manchester, an association was formed, in 1854, 10 persons died due to one serious explosion in the boiler. Therefore a vigorous complain was started by the Parliamentarians and public to avoid such mishaps. Therefore for the first time in the world in 1859, the insurance company was started to examine the boiler periodically.

© PMI, NTPC

171

THE LEGISLATION In 1860, 13 persons lost their lives in West Bengal and hence in 1863, the rules were framed. In 1869, in Bombay Similar rules were introduced and since then, the boilers are inspected by the Government Agency to inspect the boilers every years. After that the rules were framed in other provinces of India. However, as the rules were not uniform in all provinces Central Government appointed a Special Committee to draft one Central Act and in 1923, The Indian Boiler Act came into being.

CASE HISTORY In 1966, in one of the oil mill in Marathwada, the owner was found illegally using the so called by boiler. He was therefore served with a notice-and was informed to stop the boiler. Tie owner however took no notice and the so called baby boiler which made like a vertical cross tube boiler approx. 5' long x 3 ft, dia exploded like an atom bomb. The fireman who was attending the boiler was torn into pieces. His head was found 80 ft. away from the North side of the boiler and his body and two hands were found 110 ft. away from the boiler in the opposite direction. The boiler was exploded and destroyed the building to rubbles and was found from the neighbors filed in the south direction at 102 ft. away from its original place.

EXPLOSIVE POWER OF STEAM BOILER Explosion hazard of a steam boiler could be estimated from a fact that one cubic foot or 0.28 M3 of water in a boiler at a pressure of only 60 (P.S.I.) 4.2 kg/cm2 and corresponding saturation temp. of (297°F) 147°C has an explosive power of (one pound) 6.45 kgs. of gun powder Hence you can imagine the number of bombs stored in a Lancashire boiler having 150 Ibs. PSI. working pressure. It must be imagined that water escaping from a damaged boiler will expand 1600 © PMI, NTPC

172

times. This means that every litre of water escaping from the damaged boiler will be 1600 litres. Due to the above, a boiler weighing (3900 Ibs.) 17,690 kg will rocket in the air two miles. Hence the destruction force in a boiler is directly proportional the amount of water in it.

SAFETY ASPECTS Accident in the boiler just do not happen but they are caused due to ignorance or negligence on the part of engineers and boiler attendant. The persons in charge of boilers should realise that they are the custodians of so may atom bombs stored inside the boiler and hence they should exercise vigilance so that no damage can occur to the boiler and while operating they should follow the instructions which are given separately on the attached sheet.

DESIGN OF STEAM BOILER The boilers are designed in our country mainly as per the Indian Boiler Regulations. 1950. However lately I.S.O. (International Organization for Standardization) R 831 is also used. There are other codes e.g. the B.S.S Code, A.S.M.E. Code, J.I.S. Code and T.E.M.A. Code use in other countries.

Now, all boilers which are designed as per the above codes are more or less of similar nature and no boiler will be manufactured and accepted at the users sand unless the same is inspected at every stage of construction by the Inspecting Authority, approved by the code.

MATERIALS All materials e.g. plates rivets, bars, tubes, welding electrodes are required to be tested before use and should confirm boilers, steam pipes, economisers, and super heaters must possess the certificate called "Class A Welder's Certificate". © PMI, NTPC

173

This certificate is issued by the Chief Inspector after taking the different kinds of tests of the welders.

DESIGN A drawing to a scale not less than 3/4" to a foot in case of large boiler or 1.5" to a foot in case of small boiler should be submitted to the Chief Inspector before fabricating any boiler and his approval should be obtained prior to the fabrication. All principal dimensions, longitudinal sections and end view of the boiler should be shown. The other details, (e.g. pitch of rivets. longitudinal and circumferential seam details, welding details radial of curvature of dish and plate,) fillets, flanges, corners of bend plates, gusset stays, the number of rivets, diameter of rivets etc. should be clearly shown in the drawing.

CONSTRUCTION Boilers are mainly constructed either by riveting or by welding. However, in each case the boilers is inspected by the inspecting authority at every stage of construction, according to Indian Boiler Regulation or I.S.O. Code

THE STAGES OF CONSTRUCTION FOR SHELL TYPE BOILERS −

Inspection of plate with the plate certificated from the steel makers. The plates are accepted if they are manufactured by the "Well-known Steel Makers" listed under Indian Boiler Regulations, 1950.

−

After rolling the plate, the plate should be checked for its circularity and weld preparation.

−

After welding longitudinal seams, final circularity should be checked before other assembly.

© PMI, NTPC

174

−

The longitudinal seam must be X-rayed and should be free from any welding defects

−

Other belts of shell or furnaces (if any) to be attached and alignment and weld preparation sho uld be checked.

−

Drilling of tube plates and its weld preparation should be checked before fitting for true circularity and ligaments of the holes.

−

Set up of all stand pipes or pads and compensating rings for manhole, mudholes etc. Assembly of furnace, tube plate or Reversing chambers.

−

Boiler should be inspected thoroughly before stress reliving, along with Manhole Mudhole covers, test plates, and all other welding e.g. lifting lugs or angle iron for brickwork and Smoke Box,

−

Boiler to be inspected after stress reliving along with its test plates, before hydraulic test.

−

If it is all welded boiler, the specimen of the test places are tested for the following tests.

(a) Tensile, (b) Izod impact, (c) Ultrasonic, (d) Dye penetration, (e) X-ray, (f) Micro-macro. −

If the specimens are found satisfactory in the above stages the boiler is hydraulically tested to 1/3 times plus 50 pounds at the manufacturer's place and will be stamped by the Inspecting Offices as follows:

© PMI, NTPC

175

________________________________________________________________ Maker's name .....................................................................................................………………….. Workers number .....................................................................................................………………….. Tested to ....................................................................................................…………………… Working pressure ................................................................................................................................ Inspecting Officer or Inspecting Authority Stamp.

OPERATION OF BOILER The boiler after leaving the manufacturer's place, when comes to the user's place it is required to be registered under section 7 of the Indian Boiler Act, 1923. The owner of the boiler must apply to Chief Inspector of Steam Boiler for the registration along with all drawings maker's papers and requisite amount for inspection fee. The Chief Inspector or Inspector in turn will give the notice to the owner of boiler to prepare the boiler for registration inspection.

On the date fixed by the Chief Inspector, the Inspector shall proceed to measure and examine the boiler and to determine in the prescribed manner the maximum pressure, if any, at which such boiler may be used, and shall report the result of the examination to the Chief Inspector in the prescribed from. The Chief Inspector on the receipt of the report will either refuse registration of boiler or will accept the boiler. In case he refuse to register the boiler, he will give reason for doing so and if he will accept the boiler, he will forward the registry number to engrave on the boiler.

Following precautions should be taken by the boiler operators or engineers before firing the boiler.

© PMI, NTPC

176

−

see that there is sufficient water in the boiler, and that the gauge cocks are working freely,

−

ease safety valves, or open cock on top of boiler to allow air to escape,

−

see that the blow off cock is fully closed and tight,

−

see that the safety valves and feed check valve are free and workable,

−

note if the pressure gauge pointer is at zero,

−

see that the feed pump is in working order.

He must not relay on the supposition that the water he has previously put in it still in the boiler, as it may have run out without the kno wledge through a leak or open cock, nor can be sure that the gauge glass shows the true water level until he has tested it. This is done in the following manner shut off the lower gauge cock and empty the glass by the drain cock, then shut the drain cock and open the gauge cock, if everything is in order, the water will then rise in the glass to the same height as before.

Raising Steam

In getting up steam in all types of boiler the operation should be as gradual as circumstances will allow. Nothing turns a new boiler into an old one sooner than getting up steam too quickly. Forcing the fires when starting work is liable to cause starting of the steams and tubes of the boiler. In the case of large boilers generally steam should not be got up in less than six hours.

Before getting up steam, the water level should be observed, to ensure that water is at the proper heights in the glass the pressure gauge noted and the

© PMI, NTPC

177

safety valves tried to see they are free. The blow-off cock should be examined to see that it is completely shut and tight.

Pressure Gauge

The pressure or steam gauge should be kept in order and be in such a position as to be easily • seen by the boiler attendant. There should be a plain mark on it showing the highest pressure allowed for the boiler and the dial should be kept clean so that the figures may easily be read.

Steam Pressure

Ordinarily, the safety valve will prevent the steam from rising much above the working pressure as to indicate danger of exceeding the highest limit, water should be immediately fed into the boiler and the dampers partially closed in order to diminish the effect of the fire. If however, the water has fallen so low that there is danger of an accident from this cause the fires should be withdrawn before feeding in water. The safety valves eased, and if the engine is at rest it should be started so as to reduce the pressure.

The safety valves are provided to guard against over-pressure.

The should be moved by hand every day so as to prevent them from sticking, if necessary occasionally, they are liable to leak.

The valve can be tested by slowly raising it a little, and when let down, it should close perfectly tight. It should never be opened by a sudden knock or pull. If it does not close tight turn it on it seat until it fits, or when its construction does not permit this, raise it slowly a few times and let it down again, but on no account must the valve be screwed down further or loaded more than what has been allowed by the Inspector,

© PMI, NTPC

178

Safety valves must never be over-loaded, and spring valves should have ferrules or other provisions against the valves being screwed down too far. In case of an accident resulting, from overloading, the culprit might be held criminal responsible at the official inquiry or inquest

Low Water Safety Valves

If there is low water safety valve test it occasionally by lowering the water level to see that valve, begins to blow at the right point. It should give warning "before" the water level has sunk too low and before damage can be done-when the boiler is open, examine the floats and lever and see that they are free and that they give the valve the full rise. With the ordinary type of high steam and low water safety valve the float should be down at its lowest position and the valve full open when the boiler is empty.

The Water Gauge

These will be kept in best order by frequently blowing through. The cocks are thus kept in good working condition without leaking. Blow through the drain cock at the bottom of the gauge, and shut and open the steam and water cocks every few hour. These cocks should be blown through more frequently when the water is dirty. Should either of the passage become checked, or whoever the water in the gauge glass moves sluggishly the passage must be cleaned. This is best done with a wire. The gauge glass is so arranged that its top cock connects with the steam space and its bottom cock is below the water line. The water line will ordinary be near the middle of the glass tube. Always test and at the commencement of every shift. This is done by first opening drain cock and then shutting the upper cock which should give water, the upper cock should then be opened and the bottom cock closed which should give steam during this test the drain cock should be kept open.

© PMI, NTPC

179

If water and steam do not appear in proper order the cocks are choked and the passage should be cleaned. The lesson the risk of breaking the gauge glass the water cock should always be reopened after the steam cock.

Gauge glasses with a narrow white stripe running the whole length of the glass on the side next the boiler are recommended as they show the water line more clearly especially when the water is dim.

The boiler regulations framed by the Board require every water gauge glass to be fitted with a guard to prevent injury to the attendants. See that it is always in place, and clear when them steam in the boiler.

Special Note

It does not follow that there is plenty of water in the boiler because there is plenty of water in the gauge glass. The passages may be chocked and empty gauge glasses are sometimes mistaken for full ones, and explosions have resulted therefrom. Hence the importance of keeping the gauge cocks perfectly tight and clean and of blowing through the test cocks frequently.

A large number of accidents have been due to in-operative water gauges and to negligence of the attendant in not carefully reading the water level.

The Blow-Off Cock

The blow-off should be used daily if the water is at all dirty or sedimentary, especially with Locomotive type end Vertical Boilers, as their narrow water spaces are liable to get choked with mud, which soon hardness into a solid mass. The amount water to be blown out depends on the size of the boiler and can be determined only from experience. When blowing out, the best result is obtained if the water has been at rest for some time (say before the engine is

© PMI, NTPC

180

started) thus giving the sediment time to settle, if the feed water is cleaned, merely turn the cock round.

The Scum Cock

When scum cocks are fitted, if the feed water is dirty, a little should blown off daily, it the water is clean merely turn the cock round. Before opening the scum cock, see that the water is at the height indicated by the water level pointer, otherwise the scumming will be ineffective. Water should be blown from the surface through the scum cock when steam is being drawn i.e., when the engine or other machinery is working.

Manhole And Other Door Joints

When making such joints the Jointing materials should never be of round sectioned packing. Care must be taken that the spigot of the door is centrally placed in the hole. as many accidents have resulted from packing being blown cut between the spigot and side of hole, even when the clearance was only 3 mm. The nuts must be carefully and evenly tightened. Further tightening should be made during the process of heating up the boiler when raising steam.

Steam Pipes

When properly arranged should give no trouble. Frequently, however, they are so designed as to contain pockets, if which, while out of use, condensed steam accumulates, Such water is exceedingly dangerous and great care should be taken to see that the pipes are properly drained before the stop valve is opened otherwise "Water hammer" will take place even with best designed steam pipes, and disastrous explosions, causing loss of life and property may occur.

© PMI, NTPC

181

Scale and Grease

Roughly speaking, scale offers a hundred times as much resistance to the passage of heat y as does a similar thickness of the steel or iron. A 12.7 mm furnace plate covered with 2.5 mm scale is as efficient a heat retarder as steel furnace 254 mm thick. Grease is (about ten times worse than scale. In a boiler at work the temperature of a clean furnace plate is only slightly in excess of that of the water in the boiler, but is scale or grease is) interposed between the water and the plate, the latter acquires a temperature more nearly approximately that of the flame with which it is in contact. If the fire is artificial draught the furnace tube may grow so hot that it elongates considerably. If additional air is a omitted during each firing, a concerting actioning of the furnace takes place, which is one of the worst cause of boiler wear and tear.

Wear and Tear can be reduced and the life of a boiler prolong if scale and grease are prevented from accumulating in a boiler. The combined effects of scale or grease (and artificial draught are disastrous. Scale of grease also causes waste of fuel.

Grease

A mixture of sedimentary water, soda and grease produces an adhesive scum. Where this is suspected, the water level should never to lowered below the furnace) top unless the boiler is after wards entered and this sum cleaned off the furnace plate before the firing again.

Sca/e Removal

The customary method is not a satisfactory or the boiler is emptied and then rolled down by opening all the manhole and the result is that the scale which

© PMI, NTPC

182

would otherwise be soft, hardens through contact with the air and acquires laborious chipper off.

A very effective, but slower method is to retain the water in the boiler until cool, and not to run it out until the man are ready to enter the boiler with water house brushes and scrapers. The scale will then the soft and removable.

If time is a consideration, the cooling can be accelerated by add cold feed to the hot water in the boiler and slowly running off the cold water. Another method is to blow off the boiler with the lowest possible pressure (not more than 1.4 kilogram per sq.cm.) and to keep it closed until cold. The scale, will then be easily removed.

Treatment of Feed Water

Many feed waters require soda or other chemicals to arrest corrosion or to change the nature of the scale.

There is no harmless chemical which will remove scale or sediment when it has once got into the boiler and the only effective process is to purify the feed water before it enters the boiler. By this means the sediment, and generally, too, the added chemical can be deposited in tanks or in filters, and therefore never goes into the boiler. Excepting when the water obtainable is very good, water purifying apparatus ought to pay and boiler owner, particularly at those works where three or more boilers aid in constant work. Boiler owners wishing to have definite advice as to the best treatment of their feed water should have it analysed at some chemical laboratory and ascertain the best treatment in the particular circumstances.

Special attention is drawn to the net infrequent but very bad practice of allowing the waste steam from the Engine Cylinders or pumps to be drained into the

© PMI, NTPC

183

Boiler Feed Water Tanks. The waste steam from cylinders is always mixed with a certain amount of oily matter which will be deposited in the feed water tanks and ultimately be pumped into the boiler, with possibly disastrous results, as it will be obvious to every careful boiler attendant that should the oil be deposited on the furnace crowns, they may become overheated and collapse.

It should be the first care of the Boiler Owner, and the Boiler Attendant to see that the feed water is kept as pure as possible. Impure feed water means additional expense in the unkeep of the Boiler.

Preservation Of Boilers When Not In Use

Steam boilers when not in use are liable to deterioration from corrosion and unless will cared for and made rust-proof, they may depreciate more rapidly than when the use. They should be thoroughly drained and thoroughly dried and all valves, cocks, and openings closed so as to exclude moisture. Another plan is to fill the boiler with water to which about 1/100 per cent caustic soda has been added.

© PMI, NTPC

184

23. Inspection Of Steam Boilers Under "The Indian Boilers" Act 1923 DEFINITION OF 'BOILER' 'Boiler' means any closed vessel exceeding 22.75 litres in capacity which is used expressly for generating steam under pressure and includes any mounting or other fitting attached to such vessel which is wholly or partly under pressure when steam is shut off.

Any steam generator falling under the above definition is required to be registered when installed for use for the first time and inspected within a period of not exceeding twelve months for rent of certificate as required under section 8 of Indian Boilers Act 1923.

The certificate authorising the use of a boiler shall cease to be in force. −

On expiry of the certificate for which it was granted, When any accident occurs to the boiler, or

−

When the boiler is moved, the boiler not being a vertical Boiler the heating surface of which is less than (18.58) sq.meters or a portable or a vehicular boiler, or

−

When any structural alternation, addition or renewal is made in or to the boiler of

−

if the Chief Inspector in any particular case so direct when any structural alternation, addition or renewal is made in or to any steam pipe attached

© PMI, NTPC

185

to the boiler, or −

on the communication to the owner of a boiler of an order of the Chief Inspector or Inspector prohibiting its use on the ground that it or any steam pipe attached there to it is in a dangerous condition.

APPLICATION FOR INSPECTION When a certificate ceases to be in force, the owner of the boiler has to apply to the Inspector for its renewal as required under Section 8(3) of Indian Boilers Act, 1923. The application is to accompanied by prescribed inspection fee which is based on the heating surface of the boiler. The boiler Inspector then shall fix a date the examination of the boiler and shall inform the owner accordingly.

On the date fixed the Inspector shall examine the boiler in the prescribed manner, and if he is satisfied that the boiler and the steam pipe or pipes attached thereto are in good condition shall issue a renewed certificate authorising the use of the boiler for such period not exceeding such maximum pressure as he thinks fit and as in accordance with the Regulations made under the Indian Boiler Act, 1923.

A renewed certificate in case of an Economiser it to be issued for a maximum period of twenty four months if the same is found to be satisfactory after inspection and for a working pressure.

INSPECTION PROCEDURE Normally if all the Pressure parts of the boiler was accessible to thorough examination, certificate is issued after examination, as in the case of a Lancashire boiler, however, if construction of a boiler has to be , followed by a hydraulic test.

© PMI, NTPC

186

Hydraulic test however has to be carried out if the boiler is shifted from its location or if the same has been repaired.

PREPARATION OF A BOILER FOR INSPECTION At every examination of a boiler for the grant or renewal of a certificate the boiler shall be empty and thoroughly clean in all its parts. All doors of manholes, handholes and thorough sight holes and cleaning plugs and all caps in the headers and mud drums of water tube boilers all fire bars, bearers, front plates; bridge plates, fire bridges, brick arches, oil fuel burners and mechanical stoker fittings shall be removed. All valves and cooks comprising the boiler mountings shall be opened up and taken apart and the valves cocks ground, when necessary before the Inspector's visit.

Provision shall if required by the Inspector, be made for renewal of lagging or brickwork or other concealing part and for the drilling of plates and for verifying the pressure gauge and safety valve dimensions and weights. All smoke tubes, exterior of water tubes, smoke boxes and external fluces shall be swept clean.

Provision shall be made for the effective disconnection with any other boiler under steam. This shall be effected either by the removal of a length of pipe from the steam and feed piping or by the inspection of substantial blank flanges. Where blank flanges are employes they shall be inserted between the flange of the chest and the pipe attached to it. No blank flange shall be inserted between a safety valve chest and the boiler.

In case of forced flow and forced circulation type of boilers, provision shall be made for checking that proper circulation is maintained through all sections of the circuit by the flow of water.

© PMI, NTPC

187

No person shall be permitted to go inside the boiler unless it is effectively disconnected as stated above.

PREPARATION FOR HYDRAULIC TEST The chests for all mountings subject to steam pressure shall be in place and shut tight or blank flanged. The safety valves shall either be jammed down or removed and the chest opening blank flanged. The attachment for the Inspector's pressure gauge and nipple for connecting the Inspector's test pump hose shall be in order. All doors shall be property jointed and tightened up. The boiler shall completely filled with water care being taken to all air to escape and if possible, a preliminary test not exceed the working pressure of the boiler be taken before the Inspection visit to test the tightness of the joints. When a boiler is hydraulically tested for the first time, it shall be entirely cleaned lagging or brickwork. At subsequent tests the lagging or brickwork or portions there of, shall be removed if required by the Inspection.

The above procedure is applicable to economisers also.

DEFECTS AND REPAIRS OF BOILERS The various defects that can develop in a boiler during operation can be summarised as under: −

Internal and external pittings and wastings.

−

Internal and external grooving.

−

Bulging due to overheating.

−

Cracks

© PMI, NTPC

188

−

Distoration due to overheating (due to fall to water level and scale).

−

Leakages through various rivetted seams.

REPAIRS TO BOILERS −

Internal pittings and internal and external local wastages can be welded and dressed smooth. General wastages should not be permitted to be welded. In case of general wastage, either the working pressure of the boiler should be refixed considering the thickness of the generally wasted portion or a flush welded patch or a rivetted patch should be fitted after cutting the defective generally wasted portion. Such defects in the boiler should not be hidden by seal welding a patch over the wasted portion.

−

Internal and external groovings and cracks can be veed out and welded and dressed mooth. However, if the plates get grooved cracked very frequently, it indicates that the plate is fatigued and is useless for further service.

−

In such cases, the defective portion should be replaced by a flush welded or rivetted patch.

−

Bulges in boilers, except these in tubes, may be permitted ccmbt pressed back if the minimum thickness at the bulged portion is sufficient for a working pressure of the boiler. Otherwise, the defective portion has to be replaced by a flush welded or rivetted patch. Similarly, distorted parts except those of tubes can be pressed back to original shape.

−

Distorted and bulged tubes have to be renewed enternally or defective portion may be replaced by butt welding new tube in position.

© PMI, NTPC

189

Leaky rivetted seams may be caulked. Leaky rivets may be caulked if the leakage is minor, otherwise the same have to be renewed by boiler quality rivet. −

All the plates used in repairing a boiler of during manufacture must be boiler quality plates. These plates must be offered for inspection alongwith the relevant steel makers certificate to the Inspector before using the same.

The boiler quality plates should have following properties.

Chemical

Composition

Sulphur

Max. 0.05%

Phosphorus

Max. 0.05%

Carbon

Max. 0.26% and special precaution should be taken

when

carbon

percentage

exceeds

0.26%.

When steels are intended for service temperatures over 700°F the silicon content shall be not less than 0.10% or alternatively, the material shall pass the proof test for creep quality of carbon steel plates of boiler quality.

If the steel is made by oxygen process, the nitrogen should not be more than 0.006%.

PHYSICAL PROPERTIES Plates for shell, but straps, gussets and stays should a tensive strength between 26 T/p.s.i. to 36 T/p.s.i. and elongation 20 to 23% min. depending on tensile strength.

© PMI, NTPC

190

Plates for flanging and furnaces:

Tensile strength

:

24-30 T/p.s.i. steel 28-30 T/p.s.i. steel

Elongation

:

Min. 23 for 24-30 T/p.s.i. steel Min. 20 for 28-32 T/p.s.i. steel

Plates for forge welding :

Tensile strength

:

24 to 30 T/p.s.i.

Elongation

:

21%

The repairs to boilers should be entrusted to a repairer who can satisfy the Chief Inspector regarding the quality of welding and other repair done by his organisation, with regard to equipment and tools and employment of trained and experience work men etc.

© PMI, NTPC

191

24. Housekeeping INTRODUCTION There is perhaps no phase of industrial accident prevention which has suffered more from lack of understanding of its importance than Plant Housekeeping. To a supervisor the responsibility of good housekeeping may have less glamour, but he cannot be indifferent to the fact that the workforce of his department is his most valuable asset and they be helped to avoid injury through maintaining an orderly department. In any case, the term 'housekeeping' in industry can no longer be mistaken for merely floor cleanliness or broomstick operations'. Housekeeping implies an orderly arrangement of operations, tools, equipment, storage facilities and supplies. It is a practical method of getting high production and improvement in employees' morale and personnel relations.

WHY GOOD HOUSEKEEPING −

The problem of Housekeeping affects every phase of productive effort. If affects the man, his tools, his job, his fellow workers, his health and welfare. If an analysis were made of the causes of accidents caused by improper or wrong handling of materials, a good percentage of it could be attributed to poor housekeeping.

-

Good Housekeeping involves two aspects :

*

That a supervisor must be convinced about the necessity of a clean, orderly, well-maintained workshop.

*

That he should be able to sell his concept to his men.

© PMI, NTPC

192

As a matter of fact, the concept of "Good Housekeeping" takes into account the fact that poorly maintained projects or plants and persons not conscious of it are a potential cause of accidents. The following simple facts should establish the worth and validity of this premise :

*

Whatever the tools and equipment, keeping them 'clean and handy' makes the job easier, more pleasant, and more satisfying.

*

If tools are well-placed and easy to find, the job runs much more smoothly and produces better results.

*

Machines work better when 'they are clean'. It is not so much the polish as the pride of workmenship which keeps production rolling.

*

The finest equipment must not run "out of control': Constant checking and good maintenance will keep it properly moving, yielding better and greater production

RESULTS OF GOOD HOUSEKEEPING The advantages immediately realised from keeping operations orderly go beyond those already mentioned. Records of individual companies definitely establish that the following results may be expected from a well-planned, and welladministered Housekeeping programme −

It costs less to operate a clean plant. Once a plant is clean, and a system has been established, less time and effort is required to keep the plant clean.

−

Production increases because once obstacles to production are removed, orderly and business-like methods can function without undue interference

© PMI, NTPC

193

or delay. −

Control of production becomes easier because materials and parts do not get lost or mixed, and because it is easier to check operations and to secure data for records.

−

Less scrap and fewer rejects result in the conservation of materials and processed parts. Unused materials, including spoilage and scrap, are easily and quickly removed to the proper place.

−

Little or no production time is lost through the need to search for tools or to clean up a space in which to work.

−

Much improperly-used floor space is released for production, maintenance and repair work are facilitated because repairmen have easy access to machines and equipment and do not have to scrape off accumulated dirt and grease.

−

Aisle traffic is accelerated, with fewer truck collisions and less ramming into machines or stored materials.

POLICIES AND PRACTICES Here is a list of some policies and practices a supervisor case set up for himself in order to secure greater cooperation and attain the maximum degree of orderly housekeeping: −

Set a good example in his own office or work area. Do not hesitate to pick up unused odds and ends or litter from the floor and put it in the waste bin. His concern about these will impress the people who work for him.

© PMI, NTPC

194

−

Appeal to employees' pride. Point out how attractive neat work areas look. Show how each employee can benefit by keeping his work space free from dirt and congestion. Make this programme as interesting as possible to the individual employee by giving him a chance to participate, by recognising his efforts and by conducting the whole programme on a basis he can understand.

Explain the specific responsibilities each employee has and explain why such assignments are necessary if a really clean department is to be maintained. Also explain how each employee can and should carry out his responsibilities.

Make sure that instructions and directions to employees are complete and are understood. Do not leave any chance for the excuse, "I did not know you meant that".

Develop a definite schedule and procedure for making department inspections and stick to the schedule. That way alone the employees will realise that you mean business.

Keep a close check on general working conditions. It is the first piece of trash on a window sill or under a bench that invites employees to add to it. Take immediate action when necessary to keep lighting, ventilation and sanitation satisfactory.

Maintain areas should be clear and clean. Establish procedures, whereby if the storage area is full, truckers bringing in materials will check with the foreman before unloading. Never let truckers leave a load in an aisle.

Encourage employees, by making it easy for them, to keep trash off the floor. Provide containers, plainly labelled, in strategic locations, and see that such containers are emptied when full.

© PMI, NTPC

195

Do not permit anything to be stored even temporarily on window edges or hung from walls.

Provide sitting accommodation for employees where needed. Discourage their sitting on boxes.

Eliminate the practice of keeping excess materials at workplaces. This is one of the most prevalent poor work habits.

Check equipment using coolants, to see that oil, coolant, and water are not allowed to leak directly on to the floor. See that absorbents are "handy for soaking up liquids spilled.

Be sure that inflammable solvents are kept in approved containers and used sparingly. Do not permit more supply than needed to be stored in the department at any time.

Encourage employees to report conditions which contribute to disorder or hazards.

Co-operate with materials handling crew by ensuring that temporary storage areas are identified and easy to use.

© PMI, NTPC

196

25. Fire Safety NECESSITY OF FIRE PREVENTION −

Increasing industrial fire losses are causing industrialists to concern themselves with the possible effects of a fire to their premises; effects, which in addition to the direct fire losses, result in loss of production, records, valuable documents, goodwill and skilled labour.

−

It, is, therefore, essential that the fire problems needs to be tackled as a whole, making use of every known means of reducing the risk or the effects of fire to the minimum.

−

Adequate means of warning and means of escape are no less important than ever before and it is now recognised by everybody concerned that if fires can be prevented or extinguished in their very early stages, all the desirable object of saving the industrial concerns from total destruction would be achieved, Hence, the initial need of fire prevention-than fire extinction.

FIRE AND ITS CONTROL -

The aim and object here is to make the reader fire conscious; thereby enabling him to protect human life and property which can be minimised if we are fire conscious and observe simple fire precautions in our day to day life.

"A little fire is quickly trodden out; which, being suffered, river can't quench". -: Shakespeare :-

© PMI, NTPC

197

Essential Elements For Combustion :

Combustion is a chemical reaction with evolution of heat and light, which is known as fire. Essential elements for combustion are :

Fuel

-

Presence of combustible material.

Heat or ignition

-

Attainment or maintenance of temperature certain minimum temperature.

Oxygen (usually from air) or "the supporter of combustion. (It is convenient to represent the three factors in form of triangle).

Elimination factors (extinction method) : The three main methods are •

Starvation or removal of fuel

•

Smothering or exclusion of oxygen.

•

Cooling or reduction of temperature.

Starvation

This method is applied in three ways.

© PMI, NTPC

198

*

By removing combustible materials from neighborhood of the fire. Examples of this are : the drainage of burning oil tankers, the demolition of the building to create a fire gap, the cutting of trenches and counter burning in forest fires etc.

*

By removing the fire from the neighborhood of the combustible material, as far instance, pulling apart a burning stack or a thatched roof etc.

*

By sub dividing the burning material when the smaller fires produced may be left to bum out or to be extinguished easily by other means.

Smothering

Under this heading, we need to consider only the reduction of oxygen contents. The general procedure in this method is to prevent or impede the access of fresh air (oxygen) to the seat of fire and allow the combustion to reduce the oxygen contents in the confined atmosphere, until it extinguishes itself. Some of the methods employed are:

*

If a person's clothing’s are on fie-, it can be extinguished with blanket.

*

Small fires can be put out by throwing sand.

*

Foam is used to smother fires in inflammable liquids.

*

An inert gas or vapour discharges in the vicinity of fire, may so reduce the oxygen contents of the atmosphere for the time being that the combustion can't be maintained viz. Carbon-di-oxide, CTC, BCF vapours etc.

© PMI, NTPC

199

Cooling

This methods embodies the principle of removing heat from fire at a rate faster than at which it is produce. Water is the best available media for this method. On application it observes the heat from combustible material and reduces the minimum required temperature to cause a fire

CLASSIFICATIONS OF FIRE −

For all practical purposes, fire may be classified under the following heads.

−

C/ass 'A' fires : Fires in ordinary combustible materials, such as wood, paper, textiles etc. where the cooling effect of water is essential for the extinction of fire.

−

C/ass 'B' fires : Fires in flammable liquids like oils, solvents, petroleum products, varnishes, paints etc. where a blanketing effect is essential.

−

C/ass 'C' fires : Fires involving gaseous substances under pressure where it is necessary to dilute the burning gas at very fast rate with-an inert gas or powder.

−

C/ass 'D' fires : Fires involving metals like aluminium magnesium etc. where the burning metal is reactive to the water and which required special extinction media or technique

−

C/ass 'E’ fires: Fires involving electrical equipment where the electrical nonconductivity of the extinguishing media is of first importance.

© PMI, NTPC

200

FIRE PREVENTION AND PROTECTION −

"Fire prevention" aims to eliminate fire or the causes of fire. The basis for any fire prevention scheme to be effective, it has to be built-in at the design stage, so that the physical arrangement of buildings and plant can be laid out accordingly. The maximum care and caution must be observed when operating plant and equipment to prevent fires and explosions from occurring.

−

"Fire protection" is the combating of fires after the start or, and during, a fire. So that power station sites have adequate fire protection there should be, in addition to an ample water supply, some consideration of adequate road access and exists, the availability of local fire brigades and a mains water supply.

−

As many of you will be employed in or around power station and you should be. concerned to : •

Minimize the chances of a fire breaking out. Ensure that if a fire does break out it is prevented from spreading rapidly.

•

Ensure that an outbreak of fire is detected in its early stages and that the brigade is called at once.

•

Ensure that appropriate fire extinguishing system or other fire fighting arrangements come into operation at once, without waiting for the brigade to' arrive.

•

Ensure that no one in the power station is in danger at any time, of death or injury from the fire and that all personnel are trained in their emergency duties.

© PMI, NTPC

201

•

Avoid indiscriminate storages of inflammable materials in and around the plant premises.

•

Ensure careful handling of in flammable materials. Ensure proper functioning of fire alarm system.

•

Ensure that personnel are well-trained in handling fire equipments.

•

Avoid in-discriminate smoking.

FIRE PRECAUTIONS −

The old maximum 'good housekeeping is good fire prevention' is still true, and the art of preventing fires lies in well maintained machinery and clean and tidy factories. To achieve these aims, the daily routing must include the inspection of plant, the reporting of defects and the removal of the common sources of fire. At a power station these include accumulations of waste materials, oil leaks, badly adjusted drive belts, self-heating of pulverized fuel dust and defective or faulty apparatus. Regular patrolling of unmanned plant is important, especially during the night hours, if fires are to be caught and dealt with in their incipient stages.

−

The need for regular vigilance can be demonstrated by the conveyor systems which supply coal to the bunkers. If hot coal from the stocking grounds or friction on rollers or any other source of ignition causes them to ignite, the rubber belts can bum so fiercely that the rollers and the conveyor structures are distorted. The conveyor system is of major importance because it is the umbilical cord of a power station, which cannot function for more than a few hours without it. If it is damaged the consequent cost of lost production will usually exceed the cost due directly to fire loss.

© PMI, NTPC

202

−

Particular care must be taken when tackling fires in contractor's huts or storage places, which often contain pressurised gas cylinders or flammable liquids - even although contractors are advised on the correct storage of these. Contractor's accommodation, being of temporary nature, is often constructed of timber and may contain many sources of ignition.

−

The correct procedure for reporting a fire must be understood by all employees. This information must be given to them on their day of employment in a power station and^ in addition, notices giving details of the procedures must be displayed in a prominent position.

STANDING FIRE ORDERS −

Any fire, either minor or major, creates a fear psychosis in the minds of these present at the scene. This leads to a general feeling of panic followed by confusion and chaos. In order to avoid the possibility of such a situation, it is necessary that Standing Fire Orders should be laid down for different buildings, plants etc. in the factory premises, these orders should precisely specify the duties, functions and responsibilities of the members of staff so that a proper systematic and coordinated action is taken in case of a fire. It is the responsibility of all concerned to explain and impress upon all the staff of importance of such Orders. They should also see that such orders are properly implemented.

© PMI, NTPC

203

26. Portable Fire Extinguishers HOW TO CHOOSE Portable extinguishers are first-aid devices provided for immediate use on fires in their incipiency and are effective only at that stage. They are the first line of defence and it is of great importance that they be immediately accessible and promptly used.

The Indian Standards Institution has classified fires according to the nature of materials on fire (IS: 2190 - 1979) the type of extinguisher to be used has been accordingly listed and this is shown in the table overleaf.

Other considerations in the selection of an extinguisher are

EASE IN HANDLING Where elderly or otherwise physically weaker persons are involved, smaller sized and lighted extinguishers should be installed.

METHOD OF OPERATION All extinguishers installed in one premise should preferably operate by the same method. For example, an "upright" extinguisher should not be installed near a "turnover" extinguisher as it can lead to confusion.

OPERATING ANGLE OF JET Extinguishers may be required to fight fires in places which cannot be easily reached such as under floor-boards, into fume hoods, etc. In such instances,

© PMI, NTPC

204

extinguishers fitted with hose are required.

EFFECTIVE RANGE Where approach to a fire may be restricted as in an overhead fire in a highceilinged room extinguishers of the appropriate range must be chosen.

SHAPE OF JET A spray rather than a jet is more suited to cover a fairly large area and where the penetration of a solid jet is not needed, surface fires in ordinary combustibles are dealt with more effectively by a spray.

TYPE OF EXTINGUISHERS In many industries the hazards of various types of materials catching fire may be present. In such places, it is advisable to have CO2 or dry chemical powder extinguishers which can safely be used on all classes of fire.

© PMI, NTPC

205

© PMI, NTPC

206

HOW TO USE PORTABLE FIRE EXTINGUISHERS Portable fire extinguishers form the first line of defence and are useful only in the initial stages of a fire.

It is important that all personnel know how to operate fire extinguishers provided in their area of work. Management should get personnel trained in the use of fire extinguishers. The time of recharging extinguishers is an opportunity to train people.

Where more than one type of extinguisher is provided, specific instructions must be given and exhibited for the correct choice and proper method of operation.

To fight a fire, take up a position where access to the fire is unrestricted but where a quick and safe retreat is possible. In an indoor fire, stay close to the door; outdoors, stay on the upwind side of the fire. A crouching posture will minimise the effects of smoke and heat. It will also help to approach the fire.

© PMI, NTPC

207

Care should be taken to ensure that a fire is completely extinguished and that it is not left smouldering.

The fire brigade must be called at the earliest and the alarm raised. Attempt to use a fire extinguisher should be made only if it is safe to do so; if the fire shows signs of going out of control, it is best not to try to use an extinguisher.

WATER EXTINGUISHERS Direct the jet at the base of the fire and sweep it across the area of fire. Attack a vertically spreading fire at its lowest point and follow it up. Search out hot spots at the end and extinguish them.

FOAM EXTINGUISHERS Where a liquid in a container is on fire, direct the jet at the far inside edge of the container, as shown, or at an adjoining vertical surface above the level of the burning liquid. This breaks the jet and allows the foam to build up and flow across the surface of the liquid.

Where this is not possible, stand well back, direct the jet as illustrated, and with a gentle sweeping movement allow the foam to drop down and lie on the surface of the liquid. The jet from a foam extinguisher should have a length of at least a meters.

Do not direct the jet directly into the liquid because this will drive the foam beneath the surface and render it ineffective in addition it may splash the fire on to the surroundings.

© PMI, NTPC

208

DRY POWDER AND CARBON DIOXIDE EXTINGUISHERS On fires involving either liquids in containers or spilled liquids, direct the jet or discharge horn towards the near edge of the fire and with a rapid sweeping motion, drive the fire towards the far edge until all the flames are extinguished. On fires in rating liquids direct the Jet or horn at the base of the flames and sweep upwards.

On fires in electrical equipment, the first requirement is to cut off the circuit. Then direct the Jet or horn straight at the fire Where the equipment is enclosed, direct the jet or horn into any opening with the object of penetrating the interior.

WATER TYPE FIRE EXTINGUISHERS Introduction

Water expelling fire extinguishers have water as on extinguishing agent which is released in the form of a Jet by means of gas pressure in the upper part of the container. The gas pressure may be induced by chemical reaction or by mechanical means.

Water expelling fire extinguishers are used mainly in class A fires (IS 2190-1979) involving ordinary combustible materials like wood, paper, textiles, etc. which are put out by the cooling action of water Besides, water when applied to burning material is converted to steam which reduces the percentage or available oxygen.

Water expelling type extinguishers should not be used on fires involving electrical equipment without de-energising them.

© PMI, NTPC

209

The various types of water expelling extinguishers are – •

Soda acid type IS: 934-1976

•

Gas Pressure actuated type IS:940-1976 and

•

Constant Air Pressure type IS: 6234-1971

The soda acid type is the most commonly used. We shall discuss about it in detail and briefly touch upon the constructional and operational part of the other two types.

SODA ACID TYPE EXTINGUISHER Construction

The various parts and contents of a soda acid extinguisher are shown in the figure.

The total liquid capacity of the body (or the solution containers) when filled to the specified level, should be 9 litres.

During manufacture, the body is required to be tested to an internal hydraulic pressure of 25 kgf/cm2 for 5 minutes.

Method Of Operation

Before actuating the extinguisher the operational instructions given on the body of the extinguisher should be read carefully. At this stage, it would be advisable to know whether soda acid extinguishers are of up-right type or turnover type

© PMI, NTPC

210

depending on their method of working. One must know the type of the extinguisher provided at a given place.

To operate the extinguisher, remove the guard cap and strike the plunger against a hard surface like the floor. Direct the jet emerging from the nozzle on the base of fire.

Principle Of Barking

When the plunger is stuck, it breaks the acid phial (bottle). The sulphuric acid and sodium bicarbonate solution react together to release carbondioxide (CO2 ). The CO2 generated creates pressure which forces the water out of the extinguisher.

© PMI, NTPC

211

Note : The CO2, acts only as a propellant and the water extinguishes the fire by cooling effect.

Care and Maintenance

For efficient performance of the extinguisher the following maintenance schedule should be adhered to:

*

At least once a week, polish the painted portions with a little colourless wax polish and the brass/chromium parts with brass/silver polish. Check the nuzzle outlet and vent holes on the threaded portions of the cap for clogging. Check that the plunger is in the fully extended position and that it is clean and free

*

Once a quarter, dismantle the components, check for any damage, clean and grease them as required, stir the solution in the extinguisher body and top up with water if the level has gone below the solution level mark. Polish all parts.

*

Annually,

operate

50%

of

the

extinguishers

and

observe

their

performance. There must be a jet of at least 6 m for a minimum 60 seconds. Clean thoroughly and subject rusty or corroded extinguishers to a pressure test.

*

Recharge the extinguisher. Tests should be arranged in such a manner that each extinguisher is discharged once in 2 years.

*

Carry out pressure tests once every 2 years on each extinguisher by means of a hydraulic test pump. The test pressure is 17.5 kgf/cm2 and is applied for 2 1/2 minutes.

© PMI, NTPC

212

GAS PRESSURE TYPE The gas-pressure type essentially has an outer container similar to that of the soda acid type. There is a gas cartridge filled with CO^ under pressure which forms the inner compartment. When the cartridge is pierced open, CO2 under pressure is released into the body of extinguisher driving water out through the discharge tube.

CONSTANT AIR PRESSURE TYPE The constant air-pressure extinguisher is filled with water and dry air is introduced through air lines till the desired pressure is built up. When air lines are removed, the container is hermetically sealed While actuating safety pin is withdrawn and valve lever is depressed resulting in a jet of water through the hose.

FOAM TYPE FIRE EXTINGUISHERS Portable extinguishers expelling foam are best suited to put out class B fires involving flammable liquids like oils, solvents, petroleum products, varnishes, paints, etc. The foam expelled by actuating the extinguisher forms a blanket over the surface of the liquid on fire and cuts out the contact of the burning liquid with air thus extinguishing the fire.

The most common type of the portable foam extinguisher covered by the Indian Standard IS : 933-1976 is discussed here.

Construction

The extinguisher shown in figure 1 alongside consists essentials of two containers the inner and the outer. © PMI, NTPC

213

These containers when filled to the specific level contain 9 litres liquid.

The outer container holds a solution of Sodium bicarbonate to which a foam stabilizer is added. The inner container (a long brass/plastic tube) contains solution of aluminium sulphate. When operated, the solution intermixes producing foam that is expelled from the extinguisher.

Method Of Operation

Remove the extinguisher from the socket

Pull the plunger rest it on notch and turn the extinguisher over shaking well, to ensure the mixing of the two liquids.

Where a liquid on fire is in a container direct the jet at the far inside edge of the container as shown in (Fig. 2) or at an adjoining vertical surface above the level

© PMI, NTPC

214

of the burning liquid. This breaks the jet and allows the foam to build up and flow across the surface of the liquid.

Where this is not possible, stand well back, direct the jet as illustrated (Fig. 3) and with a gentle sweeping movement allow the foam to drop down and lie on the surface of the liquid. The jet from a foam extinguisher should have a length of at least 6 metres.

Do not direct the jet directly into the liquid because this will drive the foam beneath the surface and render it ineffective. In addition it may splash burning liquid on to the surroundings and spread the fire.

Foam solution electrically conductive and there are not recommended for use on electrical fires. If foam is USED as a spray it is less conductive than a straight stream However, because foam is cohesive and contains materials that allow water to conduct electricity, a spray foam stream is more conductive than a water for.

Care And Maintenance

At least once a week, polish the painted portions with a little colourless wax polish and the brass/chromium parts with brass/silver polish. Check the nozzle outlet and vent holes on the threaded portions of the cap for clogging. Check that the plunger can be raised to the fully extended position and that it is clean. Return it to its normal position.

Once in a quarter dismantle the components, check for any damage clean solution in the inner and outer containers with separate clean and dry sticks. Top up with clean and fresh water as necessary Do not use the same stick fur purring both solutions and do not pour the solutions into any receptacle for starting.

© PMI, NTPC

215

Annually, operate 50°o of the extinguishers and check that it projects a jet to a distance of not less than 6 metres for a minimum period of Seconds. Clean extinguishers thoroughly and examine their inside for rust and cohesion Subject rusty or corroded extinguishers to pressure test even if they are not due for it and their performance is otherwise satisfactory. Recharge the tested extinguishers.

Carry out pressure tests once every 2 years on each extinguisher by means of a hydraulic test pump. The test pressure is 17.5 kgf/cm2 and is applied for 2 1/2 minutes.

DRY POWDER TYPE FIRE EXTINGUISHERS Introduction

Dry powder type fire extinguishers are suitable for tackling petroleum fires, gas fires, fires in electrical equipment and for controlling surface fires in textile fibres. These extinguishers are noted for the speed with which they put out fires.

The chemical powders employed are usually sodium based and when applied to a fire, undergo chemical reaction. The free radicals which are responsible for sustaining any fire are put out of action be the dry chemical powders and because of this, the fire dies out very fast.

© PMI, NTPC

216

Special dry powders containing mixtures of sodium, potassium and barrium compounds have been found useful in extinguishing fires in metals such as sodium and magnesium. The dry powders used should conform to 18:4308-1982 specifications.

GAS CARTRIDGE TYPE There are two types of ordinary dry powder extinguishers available viz. (1) Gas Cartridge type and (2) Stored Pressure type. The first type being the most

© PMI, NTPC

217

common will be discussed here. These extinguishers are available in 1, 2, 5 and 10 kg capacities.

Construction

The construction of this type of fire extinguisher is shown in the figure. The chemical powder is contained in the main shell of the extinguisher and CO;, gas is held under high pressure in a sealed cartridge. When the extinguisher is operated, the cartridge is broken allowing the CCX, gas to escape to the main shell and push put the powder in the form of fog.

Method Of Operation

Carry the extinguisher to the place of fire and keep it upright. Remove the safety dip and strike the knob located in the cap to actuate the piercing mechanism which in turn breaks the sealing disc of the cartridge. Direct the stream of escaping powder at the base or the flame. For effective result stand about 5 to 8 feet away and direct the stream hear the seat of the fire Progress forward, moving the nozzle rapidly with a side to side sweeping motion.

When using on outdoor, fires always operate the extinguisher from the upwind side of the fire to extend the effective range of the spray.

Care And Maintenance

Following maintenance schedules are recommended for effective performance of the extinguisher. *

Once a week −

Clean the exterior of the extinguishers, polish the painted portion

© PMI, NTPC

218

with a little colourless wax polish, polish the brass and chromium plated parts. −

Check the nozzle outlet and vent holes in the threaded portion of the cap for clogging.

− *

Check that the plunger is clean and is in fully extended position.

Once in a quarter −

Withdraw the gas cartridge and check if the sealing disc is intact. Weigh the cartridge and compare its weight with that stamped on its body. If a loss of 10% or more of the contents is noted, replace it with a fully charged one.

−

Check the piercing mechanism for its proper functioning.

−

Remove the inner shell and clean port holes if necessary. Also check the port holes in the cartridge holder and clean them if necessary

−

Check the powder for granulation and caking. If caking/granulation is observed remove and replace with fresh charge.

*

Once in a year -

One third of the total number of extinguishers of this type should be put into operation for evaluating their satisfactory performance. In the event of poor performance of any one of them, the balance will also have to be tested.

© PMI, NTPC

219

*

Once in 3 years -

Every extinguisher should be discharged at least once in 3 years. It should be hydraulically pressure tested at 17.5 kgf/cm2. However, if there is any indication of mechanical damage or corrosion to the extinguisher shell it should be pressure tested immediately. Before recharging the extinguisher should be bone dry.

CARBON DIOXIDE TYPE FIRE EXTINGUISHERS Introduction

Carbon dioxide (CO2) is effective as an extinguishing agent primarily because it reduces the oxygen content of air to a point where combustion cannot continue. CO2 is non combustible and does not react with most substances. Being a gas it can penetrate and spread to all areas affected by fire.

Carbon dioxide fire extinguishers are used for putting out fires in oils, petroleum products gaseous solutions under pressure, and also on sophisticated electrical and electronic apparatus.

Carbon dioxide extinguishers are not to be used in – •

Fires involving chemicals that contain their own oxygen supply (such as cellulose nitrate)

•

Fires involving reactive metals such as sodium, potassium and magnesium.

The common type of portable carbon dioxide extinguisher covered by IS • 28781976 is discussed here.

© PMI, NTPC

220

Construction

The principal parts of the extinguisher are as shown in the figure above. Carbon dioxide is retained in the cylinder as liquid under pressure. The cylinder is filled with the charge to about two thirds by weight of its total water capacity.

Method Of Operation

Carry the extinguisher to the place of fire. Remove the safety pin and operate the discharge device or unscrew the valve depending on the design. Carbon dioxide is delivered by means of discharge horn through a high pressure flexible hose.

Direct the jet at the base of the fire, starting at one edge and sweeping across the surface of the burning material. When used in open air. the operator should stand on the up -wind side of the fire and should apply the gas in a downwind direction as close as possible to the fire. On fires in electrical equipment first switch off the current. Then direct the jet or horn straight at the fire.

The gas at the time of discharge makes considerable noise. The user should therefore be well conversant with its operation to prevent the jet from being misdirected during the first few vital seconds.

How Does Carbon Dioxide Extinguish Fire

When the extinguisher is actuated carbon dioxide from the cylinder comes out at a considerable velocity into the atmosphere and forms a layer of gas which is about one and half times heavier than air. The vapour blanket puts out fire by displacing the air around the fire and reducing the oxygen supply needed to continue combustion.

© PMI, NTPC

221

Care And Maintenance

At least once a week, polish the painted portion with a little colourless wax polish. The brass/ chromium parts are to be polished with brass/silver polish. Check that the nozzle outlet is free from clogging.

Once a month weigh the extinguisher and if a weight difference of 10% or more (of that of a fully charged extinguisher) is observed it should be sent out for recharging. Every time the extinguisher is sent for recharging the cylinder should be pressure tested at 210 kgf/cm2 before recharging.

HALON TYPE FIRE EXTINGUISHERS Halon 1211 (Bromo chloro difluoro methane. CBrCLF2, also known as BCF), and Halon 1301 (Bromo trifluoro methane. CBrF 3, also known as BTM) are gases which can be used as an effective medium for extinguishing fires. They are

© PMI, NTPC

222

colourless and electrically non-conductive. Halon 1211 is faintly sweet-smelling whereas Halon 1301 is odourless. Compared to CO2 on a weight-of-agent basis. Halons are at least twice as effective. When discharged, the agent is in the combined form of vapour and mist with about twice the range of carbon dioxide. To some extent, windy conditions may make extinguishment difficult by causing the rapid dispersal of the agent.

Halon type fire extinguishers can be used as replacement for exiting carbon tetrachloride type fire extinguishers, the use of which has been prohibited. They are suitable for fire fighting in confined spaces for all types of Class 'B' and 'C' fires. Halon 1211 as well as Halon 1301 being non-conductive, can also be used safely on electrical fires and is a suitable alternative to CO;, or dry powder extinguishers. In using extinguishers of this type in poorly ventilated places, such as small rooms, closets or confined spares, occupants should avoid breathing gases produced by thermal decomposition.

Some of the more important types of hazards and equipment that Halon 1211 may satisfactorily protect include ;

*

Gaseous and liquid flammable materials.

*

Electrical hazards such as transformers, oil switches and circuit breakers and rotating equipment.

*

Engines utilising gasoline and other flammable fuels.

*

Ordinary combustible such as paper wood and textiles.

*

Hazardous solids.

© PMI, NTPC

223

In addition to the above, Halon 1301 can also satisfactorily protect electronic data processing equipment, control room instruments and computer installations.

Both Halon 1211 and Halon 1301 have not been found to be effective on the following: −

Certain chemicals or mixtures of chemicals such as cellulose nitrate and gun powder which are capable of rapid oxidation even in the absence of air.

−

Reactive metals such as sodium, potassium and magnesium.

−

Metal hydrides.

−

Chemicals capable of undergoing auto thermal decomposition such as certain peroxides and hydrazine.

The common type of portable fire extinguisher of Halon 1211 type covered by IS:11108 -1984 is discussed here.

Types

There are basically two types of extinguishers of the Halon 1211 type : •

Upright type with squeeze grip valve and

•

Inverted type having piercing type of valve (only those of 1.25 kg capacity)

The Upright type with squeeze grip valve is the most common type and is usually available in 2.5, 4, 5 and 6.5 kg capacities.

© PMI, NTPC

224

Construction

Some of the salient features of the common types of Halon 1211 extinguishers are :

The cylinder construction should conform to the specifications as detailed in IS:1110- 1984, made out of high quality steel treated against corrosion and having squeeze grip valves fitted with pressure indicating gauge.

*

In case of squeeze grip valve assembly, a spring-loaded, pressure sealed sliding spindle in provided in such a way that it is operated by manual depression by means of a cantilever hinged grip lever. The spindle is so designed, that the extinguisher can be regulated by means of pressing and releasing the squeeze grip handle. A safety pin is provided for prevention of accidental operation and is fitted on cantilever hinged grip lever through valve body.

*

The discharge fittings include a nozzle which is used in conjunction with a delivery hose or fitted as an integral part of the valve body.

A siphon tube is fitted to the bottom end of the valve for 'Upright type' extinguisher.

*

A hose shall be required for 4.5, 6.5 kg. capacity and is either rubber of braided hose having a bursting pressure limit of not less than 50 kg/m2.

*

A pressure gauge is fitted to the extinguisher to indicate its internal pressure. The gauge is usually marked suitably with normal pressure at which the extinguisher is charged and also indicates when it is wholly or partially released.

© PMI, NTPC

225

*

The extinguishers are pressurised using dry nitrogen to ensure proper operation (although the agent is usually retained in a liquid state under its vapour pressure and is self-expelling).

Method Of Operation

For Upright type fitted with squeeze grip valves :

*

Carry the extinguisher to the place of fire,

*

Hold the extinguisher upright.

*

Remove the safety pin from the valve handle.

*

Press down the spring-loaded spindle by pressing downwards the operation handle thereby controlling the discharge of the contents.

Note :-

On flammable liquid fires, best results are obtained when the discharge from the extinguisher is employed to sweep the flame off the burning surface, by applying the discharge first at the near edge of the fire and gradually progressing towards the back of the fire by moving the discharge with a side-to-side sweeping motion.

Extinguisher should be discharged initially from a distance not closer than 2.5 metres to prevent splashing when applied to depths of flammable liquid.

Principle of working Upon actuation, the vapour pressure causes the agent to expand so that the discharge stream consists of a mixture of vapour and liquid droplets.

© PMI, NTPC

226

Method of extinguishment According to present knowledge, Halon 1211 and Halon 1301 extinguish fires by inhibiting interaction of fuel vapour and oxygen. The extinguishing effect due in cooling is minor.

Care And Maintenance

The

following

maintenance

schedules

are

recommended

for

effective

performance of the extinguisher. −

Once a week. clean the exterior of the extinguishers, and polish the brass and chromium plated parts. Check that the nozzle outlet is free from clogging.

−

Once a month, weight the extinguisher to check the total weight of the extinguisher and if weight difference of 10% or more (of that of the fully charged extinguisher) is observed it should be sent for recharging.

−

Check the pressure indicating gauge regularly. If loss of pressure exceeds 10% as shown on indicating gauge, the extinguisher should be sent for recharging.

−

Every six years, stored pressured extinguishers are to be emptied and subjected to internal examination.

−

Once in 12 years, these extinguishers are to be subjected to hydrostatic test as a test pressure not exceeding two times the service pressure.

© PMI, NTPC

227

FIRE FIGHTING SYSTEMS Hydrant Systems and Associated Equipment

Hydrant systems for the protection of buildings and plant involve the provision not only of adequate water supplies but also of the piping, control valves, hydrants, standpipes, couplings, adaptors, hose, breachings, branches and nozzles, which are used to bring the water from the source of supply to that part of a building where it may be required for fire fighting. Hydrant systems should be quite separate from, and independent of, any sprinkler or drencher system and from the general water supply. They should normally be kept charged with water, but in certain circumstances hydrants may be attached to a dry riser.

Station Internal Hydrant System

Water is supplied by an electrically driven pump normally started from the control room; there is a diesel driven pump as an automatic standby. The pumps supply a large number of hydrants around the power station and the system reaches all major fire risk areas. The interna l ring main supplies hydrants in the turbine and boiler-house basements and on the operating floors, and the hose reels at the bunker floor. It also supplied dry rises to the boiler and bunker house roofs, and the hose reels on coal conveyors. From the Internal ring main there are also couplings on each boiler for economiser washing and connection to the air heater washing ring main.

Station External Hydrant System

Hydrants served by a ring main should be positioned about the power station site and should be sufficient in number and so located that all buildings and risks on site can be readily protected by the.

© PMI, NTPC

228

Automatic Sprinkler Systems

Since a most important principle of successful fire extinction is to tackle a fire in its early stages you can appreciate that any device which can detect fire, proceed to extinguish it and transmit an alarm will be valuable. A sprinkler installation consists essentially of a system of pipework erected at par near the ceiling of each floor of a building to be protected and connected through controlling valves to one or more water supplies. At intervals in the pipe work are sealed outlets called sprinklers (sprinkler heads). These contain a device which, at a predetermined rise in temperature, causes the sprinkler to open and water to be discharged in the form of a spray over an area of the floor below the sprinkler. The sprinklers are spaced so that, if two or more heads operate simultaneously, the areas spread by each sprinkler overlap so that no part of the floor is unprotected.

Water Spray Projector Systems

Water spray projector systems, as opposed to sprinkler or drencher systems, are used almost entirely for the protection of equipment against all fires. The principle involved is to apply the water in such a manner that the flammable liquid is changed temporarily into one, which is incapable of burning, by forming an oil-inwater emulsion at the surface. An additional and important advantage of emulsifying the surface zone of the burning liquid is that breaking up of the oil into small globules dispersed in water, give rapid cooling. Vapour is no longer produced and given off and the development of an explosive atmosphere, after the fire is extinguished, is avoided.

Controls and Alarms

The multiple jet type of layout is used in power stations where the risk can be effectively subdivided. A water spray projectors system is usually automatic in

© PMI, NTPC

229

operation, but for certain special installations manual control is employed instead of, or in addition to, automatic control. Manual control is used to protect the lubricating oil systems of turbo-generators because of the possibility of leakage from nearby high temperature steam pipes; the leaking steam could cause quartzoid bulb detectors of an automatic system to burst and so open the system. Manually operated valves are placed in convenient positions outside the probable zone of fire, but in situations from which a fire could be observed, preferably on the turbine operating floor and not in the basement. Electrically operated valves with remote control from unit or central control rooms are also in use.

Water Supplies

Water spray projector systems must have a reliable and adequate supply of water at the required pressure. This should be enough to be able to supply all the projectors likely to be brought into operation for a period of five minutes. When all the projectors that are to be brought into operation at one time are discharging water, the minimum running pressure at the projectors should be not less than 3.5 bar (50 Ibf/in2). In power stations, the quantity of water required means that storage tanks or reservoirs and pumping sets have to be arrangement to start automatically & immediately the operation of the system causes a demand for water. FIRE DETECTION SYSTEMS

Fire grow to disastrous proportions either because their discovery is delayed or because they cannot be successfully fought in time with the means available. The very essence of successful fire protection is to ensure that fires can be detected and fought within a few minutes of their breaking out. Fire detection systems are devices designed to give a warning of an outbreak of fire or of conditions likely to result in such an outbreak; these devices also transmit that

© PMI, NTPC

230

warning to a place where a appropriate action will be taken or receipt of the warning. We can say, therefore, that detection systems have two distinct functions :

*

To detect a fire.

*

To transmit a warning.

Classification

Broadly, there are two classes of fire detection systems: those with detectors which respond to heat and those with detectors which respond to smoke. Both classes are invariably electrically operated, and we shall describe both in the next subsections. In some cases the alarm is given by the completion of a circuit when a detector operates (open circuit), while in others a small current flows continuously and the alarm is given when the circuit is broken by the operation of a detector (close circuit). The essential components of automatic fire detection systems, in addition to the wiring, are the detectors, visual indicating panels, audible warning devices, equipment for calling fire brigades, and power supplies. The systems usually operate on batteries which are trickle-charged from the mains supply.

Heat Detectors

There are two types, of heat detectors. The more common type is the point detector, which is relatively small, and the other type is the line detector breaklink cable, which has a long continuous sensitive element extending over a large area of a ceiling. Sensing elements used in heat detectors include :

*

Metal strips, rods, wires or coils which expand when heated.

© PMI, NTPC

231

*

Fusible alloys.

*

Conductors whose electrical existence is altered by heating.

*

Hollow tubes containing a fluid which expands on heating and applies pressure to a diaphragm.

*

Thermocouples.

Smoke Detectors

Smoke detectors pond to the smoke or other products of combustion evolved from a fire. There are two main types; one utilizes the effect of the products of combustion on the current flowing across an open ionization chamber and the other operates on the photo -electric principle. In the case of the latter, smoke entering the detector diffuses internal lamp lights around an opaque barrier to reach the photoelectric cell, which actuates the alarm system. Smoke detectors can be designed to be extremely sensitive, and in certain circumstances may detect fires before heat detectors, but they have limitations to their general use in industry.

Laser Beam Fire Detector

Experiments have been carried out using a laser beam impinging on a photoelectric cell, either directly or by reflecting the beam by a corner reflector, so that the effect of building movements are minimised. A rising plume of hot gases from a fire is turbulent, and this causes the refractive index of the air to change so that the position of the laser beam varies randomly and the laser spot falling on the photoelectric cell becomes perturbed. After the fire has been burning for a minute or so, the beam as a whole is deflected, as a temperature gradient becomes established near the ceiling, and the spot moves away from the photoelectric cell.

© PMI, NTPC

232

The first indication of a fire is, therefore, the agitated movements of the spot; these give a variable output from the cell and this is closely followed by a fall in the mean output.

© PMI, NTPC

233

27. Fire Prevention And Protection System For Thermal Power Stations INTRODUCTION -

The circumstances under which a Thermal Power Station has to operate with coal. different kinds of oils, hydrogen, variety of rotating electrical and mechanical equipment, cables, pipelines carrying steam etc. make the plant to face always the threat of fire hazard. It is, therefore, essential for engineers to install an efficient fire prevention and fire fighting system as integral part of every Thermal Power Station.

SCOPE OF FIRE PROTECTION SYSTEM -

The Fire Protection System consists of Fire Hydrant, High Velocity (H.V.) sprinkler system and portable chemical extinguishers alongwith smoke detection system for cable vaults and UCB's.

-

A brief scope of fire protection system which should be provided in the station is given below :-

-

Automatic hydrant system consisting of fire water pumps, jockey pump alongwith hydropneumatic pressurizing system, piping (both indoor and outdoor) located throughout the entire power station at strategic locations within power house and other buildings. hose pipes, nozzles etc. Following areas are normally protected by Hydrant System. •

Power house and boiler area

© PMI, NTPC

234

•

Intake & service water pump house

•

Clarified water pump house & raw water pump house

•

Ash water and slurry pump house

•

Water treatment plant area

•

Compressor house

•

Administrative Building

•

Outdoor yard

•

Fuel oil pump house & storage area

•

Transformer yard

•

Fire Station

•

Start-up boiler

•

Hydrogen generating plant

•

Coal handling plant including crusher house Service building Petrol pump & autobase workshop

•

Canteen, training institute, simulator building, wagon repair shop.

© PMI, NTPC

235

-

Automatic High Velocity (H.V.) sprinkler protection consisting of deluge valves, heat detectors, projectors, piping, valves, fittings etc. for the following :

-

-

•

Generator transformers

•

Unit auxiliary transformers

•

Station transformers

•

Tie transformers

•

Centralised turbine oil purification system.

Smoke detection (Fire Alarm) system for •

Electrical cable spreader room

•

Cable vaults

•

Unit control & equipment room

•

MCC rooms

Portable and mobile (wheel mounted type chemical the extinguishers of soda acid, carbon dioxide, foam type, dry chemical powder type.

FIRE PREVENTIVE MEASURES -

The importance of fire preventive measures needs no over-emphasis as this goes a long way in preventing the occurrence of fires. Though

© PMI, NTPC

236

normally all safety and preventive measures as enforced by site authorities are to be strictly followed, it is suggested that following preventive measures should be strictly followed at project sites: •

The 'house-keeping' of plant should be of highest order. Waste cotton wool, oil spillage etc. should not be allowed in the plant areas, especially cable trenches, cable galleries/vaults areas. These should be checked regularly and any foreign/ waste material found should be immediately removed.

•

All combustible materials lying in the vicinity of welding and cutting operations (carried out on a very large scale during erection) must be removed or covered as welding spark can travel upto 10 meters and cause size able fires. Such operations should be supervised by the fire fighting squad and adequate number of portable extinguishers must be kept in readiness. In fact, welding/ cutting work should be allowed only with permission of competent authority after ensuring that all necessary fire prevention rules.

•

In power plant coal dust settlement on various floor levels, cable trays etc. can happen which if allowed will lead to be a potential source of fire. This should be eliminated and cleaning if required with the help of pressurised water spray system and/or vacuum cleaners should be carried out as a routine.

§

Emergency exit from various locations (with arrow 'Exit' marking), should be provided throughout the plant.

§

All fire fighting equipment & apparatus should be maintained properly and regular drill of fire protection as advised by project authorities should be conducted and records maintained. This will

© PMI, NTPC

237

ensure regular check on working of all fire fighting equipment and accessories.

Additional fire protection Measures

Following features should be adopted as additional fire protection measures.

Cable Galleries/Value, Cable Trenches etc.

*

All cable risers/shaft at various floor levels originating from cable galleries should be effectively sealed to avoid draught effect and consequently spreading of fire.

*

Similarly cable trenches bifurcating from cable galleries should be effecti vely sealed to prevent entry of water, dirt, snakes, rats etc. entering the zub-zero cable galleries, which would result in good up keeping and clean environment inside the gallery.

*

Cable galleries of power house should be partitioned with fire barriers wall unit wise with self closing fire resistant door and an automatic detection and automatic fire sprinkler system should be provided. However, it is to be ensured that adequate capacity sump pumps and drainage arrangement for water is to be provided in these galleries.

*

All outdoor cable trenches should be periodically inspected for cleanliness and wherever possible these trenches may be filled with sand.

Switchgear Rooms, MCC Rooms etc

Switchgear rooms & MCC rooms should be provided with fire alarm system using ionisation type detectors for early warning in case of fire.

© PMI, NTPC

238

Unit Control Rooms, Unit Control Equipment Rooms and Inverter Rooms

Ionisation type Smoke detectors should be installed in units control and equipment rooms & inverter room. For protection it is recommended to provide Halon 1301 gas flooding in case of fire, to avoid a possible damage to these areas in the event of fire. Use of Halon-1301 gas in place of CO;, has achieved considerably momentum. This is one of the best suited medium for fire protection in view of the following advantage: •

It is a very fast extinguishing medium (any fire can be extinguished in 1015 seconds) and have no harmful effect on any equipment.

•

It can be released in any human occupied areas without any ill effect on human being unlike CO2 flooding which call evacuation of personnel through a pre-alarm warning before flooding the CO2 gas.

•

Unlike CO^ as extinguishing medium which requires complete removal of CO2 gas after fire extinguishment before any personnel can occupy that area, Halon 1301 does not call for this requirement as concentration of Halon gas required for fire extinguishing is 5-7% (against CO2 40-50%) and this concentration has not ill effect on human life.

Presently Halon-1301 gas is imported and only filling is being done in India. In the past we have not considered this for life protection in TPS. However, today for defence establishment, power stations and other projects use of Halon-1301 gas for fire protection, especially for control rooms etc. has emerged as the best technical solution.

© PMI, NTPC

239

PROTECTION FOR TURBINE OIL TANKS AND ACCESSORIES Following equipments should be protected by Automatic/manual H.V. sprinkler system.

a)

Turbine oil main storage

b)

Unit Turbine oil tanks

c)

Lube oil pipes (zones)

d)

Oil coolers

e)

Seal oil system

For fuel oil handling storage areas, at present only fire hydrant system is provided. It is proposed to augment the fire protection for this area as outlined below : •

It is envisaged to install foam tanks in the fuel oil facilities areas and inject the foam through nozzles mounted inside the top of fuel oil tanks manually in case of fire. Water for this shall be tapped from sprinkler header running for C.H.P., cable gallery protection etc.

•

Apart from foam injection system to be provided as discussed above, a medium velocity spray system shall also be provided outside the tank to provide cooling effect to the tank which will ensure that in case of fire other tanks are protected from the possibility of fire.

© PMI, NTPC

240

Coal Handling Storage Areas, Coal Handling Plant Protection

For coal stock piles, at present it is protected by hydrant is envisaged. However, to avoid spontaneous combustion in piles due to air pockets, it is suggested that compaction of coal piles thru bull-dozer should be done as much as possible. For coal handling plant, all underground tunnel including track hopper and overground covered conveyors upto the bunker floor, it is recommended to install a system having automatic detection cum-sprinkler system.

Coal Bunkers Protection

Fire in coal bunkers is due to spontaneous combustion of coal due to its storage for a long time and its is smouldering in nature. However it is not possible to install any system which can extinguish the same. Only fire on surface can be extinguished by flooding CO2 in the bunkers, but this would have no effect on deep seated fires in bunkers. Hence it is not possible to provide any automatic detection' and suppression of fire which will be quite 4 effective. The only solution is to provide a battery of carbon-dioxide cylinder with piped gas connections in the bunkers and in case of fire CO2 would be replaced in the particular bunker manually. Since, as explained above, this would be effective only on surface fire and smouldering would start again once the gas is finished. Moreover keeping in view the large size of bunkers and their numbers, the system would require a large number of cylinders and refilling. It is concluded that CO2 injection system for bunkers would neither be effective nor economically viable. Hence minor bunker fires should be fought by portable/mobile C02 extinguishers. However, in case of major fire in the bunker, it is required to empty the bunker coal by first closing the inlet gate to coal feeder, than empty it through a bypass pipe. During the coal emptying operation, the bunker top should be blanketed by CO2 flooding.

© PMI, NTPC

241

OTHER PREVENTIVE MEASURES -

Adequate quantity of portable/mobile CO2 Foam, Dry Chemical type extinguishers should be maintained at site and located in all places especially in switchgear rooms, MCC rooms, laboratory etc.

-

Suitable interlocking should be provided in the system so that in the event of fire:

*

Ventilation system, if any, provided in the cable & conveyor galleries is switched off automatically.

*

Air conditioning system in control room shall be switched off automatically.

-

Following additional annunciation should be provided:

*

Low pressure fire water alarm in central fire station and fire panel located in UCB.

*

Low fire water pressure alarm in central fire station & control room which cannot be acknowledged and would be off only when the pressure in the fire water header is restored.

-

The system should designed in such a way that there are atleast two number

diesel

engine

driven

pumps

available

as

standby

for

hydrant/mulsifire/sprinklers.

© PMI, NTPC

242

28. Introduction To First Aid PRINCIPLES AND PRACTICE OF FIRST AID -

First Aid is the skilled application of accepted principles of treatment on the occurrence of an accident or in the case of sudden illness, using facilities or materials available at the time. It is the approved method of treating a casualty until he is placed, if necessary, in the care of a doctor or removed to hospital. Because of the increasing number and serious nature of accidents of all kinds, the responsibility of the First Aider has become greater.

-

First Aid is treatment given to a casualty -

*

to sustain life.

*

to prevent his condition for becoming worse.

*

to promote his recovery.

RESPONSIBILITY OF A FIRST AIDER IN THE MANAGEMENT OF A CASUALTY -

To assess the situation :

-

To arrive at a diagnosis for each casualty;

© PMI, NTPC

243

-

To give immediate and adequate treatment, bearing in mind that a casualty may have more than one injur y and that some casualties will require more urgent attention than others;

-

To arrange without delay for the disposal of a casualty according to the seriousness of his condition.

ASSESSMENT AND INITIAL ACTION -

Be calm, take charge.

-

Give confidence to the conscious casualty.

-

Talk to him, listen to him and reassure him.

-

Check

*

Safety of casualties and of yourself;

*

the breathing, for bleeding and whether conscious.

-

Get others to help.

-

Tell them what they should do.

-

If necessary, send for ambulance, police, fire service, or other help.

© PMI, NTPC

244

DIAGNOSIS -

The history of the incident must be taken into consideration and an examination made to determine the signs and symptoms and level of consciousness.

-

History The story of how the accident happened or the illness began obtained from –

-

The casualty

: 'I slipped and fell down'.

Witness

; 'I saw the old man fall and his head strike the wall'.

Signs Variation from normal, ascertained by the First Aider - pailor ; blueness (cyanosis) of face, lips inner sides of eyelids, or of nail beds of fingers and toes. There may be evidence o\ poisoning.

-

Symptoms Sensations described by the casualty 'I feel pain' 'I am cold' ‘My arm is numb'.

LEVEL OF CONSCIOUSNESS Any change of level is important. Full consciousness Able to speak and answer questions normally. Drowsiness.

© PMI, NTPC

245

Easily roused, but lapses into unconsciousness.

Stupor Can be roused with difficulty. The casualty is aware of painful stimuli, e.g. pin prick, but not of other external events, e.g. being spoken to.

Coma Cannot be roused by any stimuli.

ACTION -

If the cause of the condition is still active, remove it -

*

a log of wood on the casualty's leg,

*

contaminated clothing

*

or remove the casualty from the cause - from traffic, fire, water, poisonous fumes etc.

TREATMENT

Give the treatment you consider essential.

Sustain life.

Emergency resuscitation.

Control bleeding and shock.

© PMI, NTPC

246

-

Prevent the condition from becoming worse

Cover wounds

Immobilise fractures, large wounds and any injured part. Place the casualty in a correct and comfortable position.

-

Promote recovery

Reassure

Give any other treatment needed.

Relieve pain.

Handle gently and carefully at all times.

Move as little as possible.

Protect from cold.

DISPOSAL -

The First Aider will ensure that the casualty is conveyed without delay to his home, a suitable shelter or an appropriate hospital. In serious cases it may be necessary to summon a doctor.

-

A brief written should accompany the casualty. A tactful message should also be sent, if necessary, to the casualty's home stating what has happened and where he has been taken, unless this has been done by the police or other authority.

© PMI, NTPC

247

SUMMARY OF ESSENTIALS OF FIRST AID -

Act quickly, quietly and methodically, giving priority to the most urgent conditions. Ensure that there is no further danger to the casualty or to yourself.

-

If breathing has stopped or is failing, clear the airway and, if necessary, start emergency resuscitation Control bleeding.

Determine the level of consciousness. Consider the possibility of poisoning. Give reassurance as necessary to the casualty and to those around and so help to lessen anxiety. Guard against shock. Position the casualty correctly. Before moving the casualty, immobilise fractures and large wounds. Arrange without delay for the careful conveyance of the casualty, if necessary, to the care of his doctor or to a hospital.

Watch and record any changes in the conditions of the casualty. Do not attempt too much; Do not allow people to crowd around: this hinders first aid and may cause the casualty anxiety or embarrassment; Do not give anything by mouth to a casualty who is unconscious, who has suspected internal injury, or who may shortly need an anesthetic.

Definitions -

Medical aid indicates treatment by a doctor.

-

First Aider

The term First Aider was devised to designate any person who had received a certificate from an authorised Association that he or she is qualified to render First Aid. It was first used in this way in 1894 by the Voluntary First Aid Organisation.

© PMI, NTPC

248

-

Such certificates issued by St. John Ambulance, St. Andrew's Ambulance Association and British Red Cross Society are awarded to candidates who have attended a course of theoretical and practical work, and who have passed an examination conducted by a specially appointed doctor.

-

The certificate awarded has a limited validity to three years thus ensuring that First Aiders are –

*

Highly trained;

*

regularly examined;

*

kept up-to-date in knowledge and skill.

© PMI, NTPC

249

29. First Aid To The Injured DRESSING AND BANDAGES DRESSINGS A dressing is a covering applied to a wound or to an injured part and may be used:•

To assist in controlling bleeding (hemorrhage)

•

To protect a wound from further injury

•

To prevent or lessen infection

Prepared Sterile Dressing

The ideal dressing for all wounds consists of a sterilised (germ-free) piece of gauze or lint to which is sometimes stitched a pad and a roller bandage. This dressing is enclosed and sealed in a protective covering. To use a prepared sterile dressing :-

If possible, wash the hands thoroughly, with soap and running water; they must not, however, be regarded as sterile, Loosen the protective covering and remove the dressing. Expose the dressing as little as possible to the air. Do not breathe or cough over it. Avoid fingering the dressing which is to be applied to the wound. Do not handle anything else which is not clean.

Gauze or Lint

© PMI, NTPC

250

If a prepared sterile dressing is to available, cover the wound with a piece of clean gauze or lint (smooth side towards the wound). To use gauze or lint, loosen the covering and with clean scissors cut a piece to the 'size required to cover the wound adequately; take care not to touch the side which is to be applied to the wound.

Place the unused portion of the gauze or lint in a clean container.

Emergency Dressings

If a prepared sterile dressing or gauze or lint is not immediately available, the inside fold of a clean handkerchief or freshly laundered towel, a piece of linen or clean paper tissue may be used but their use is only temporary until a prepared sterile dressing or gauze lint is available. The greatest care must he taken in handling and applying dressings to avoid touching with the naked fingers any part of the wound or any part of the dressing which will be in contact with the wound. The object is to prevent further contamination by germs. Dressings must be covered with an adequate pad of cotton wool which must extend well beyond the dressing and be kept in place with a bandage. Clean linen or any other soft bulky material may be used as a pad if cotton wool is not available.

"A Cold Compress (wet dressing) may help to limit swelling and bleeding under the skin. To make a cold compress; take a thin towel, piece of lint, flannel, cotton wool or handkerchief and soak it in cold water*" Squeeze out the water to that the material does not drip but do not wring it dry. Keep the compress moist by dripping on more water from time to time or by replacing it by another freshly prepared. The addition of a little methylated spirit may help evaporation and so increase the effect of the compress. Do not cover the compress but if it is necessary to secure it in position use the minimum of bandaging and use upon wove material if available. Do not apply a wet dressing where there is an open wound or use methylated spirit near the eyes.

© PMI, NTPC

251

WOUNDS AND HAEMORRHAGE What is a Wound ?

A wound is a break in the continuity of the tissues of the body which thus permits the escape of blood and the entrance of disease-producing germs or other injurious agents.

Wounds may be classified as follows :•

Incised Wounds, which are caused by a sharp instrument such as a razor, and bleed freely because the blood-vessels are "clean cut".

•

Lacerated Wounds, which have torn and irregular edges. They are caused by such things as machinery, a piece of shell or the claws of an animal. As the blood-vessels are torn through, lacerated wounds bleed less freely than incised wounds.

•

Contused Wounds, which are accompanied by bruising of the tissues, and are caused by a direct blow by some blunt instrument or by crushing.

•

Punctured Wounds, which have comparatively small openings, but may be very deep and are caused by a slab from any sharp-pointed instrument, such as a needle, knife or bayonet. Gun-shot wounds come under one or more of the above headings.

Hemorrhage

Or bleeding may vary in intensity from severe to slight. Severe hemorrhage comes from a torn artery or torn vein or both combined. Many large arteries and veins lie close together and are frequently injured together. Blood from an artery

© PMI, NTPC

252

in the systemic circulation is bright red. If the injured artery is near the skin, the blood is seen to spurt out in jets corresponding with the pulsations of the heart. Blood from a vein is dark red. It flows in a brisk continuous stream Arterial and venous hemorrhage combined usually gushes out from the depth of the wound.

-

"Infection (sepsis)" is an abnormal state of the injured tissues resulting from the invasion of disease-producing germs. Germs are invisible to the naked eye and can be seen only with II'' aid of a microscope. They exist in soil, dust water, air and in may other places including the skin and intestinal tract of both man and animals.

-

Germs are living organisms and need moisture, suitable food and favourable temperature in order to live and multiply. Disease-producing germs find ideal conditions in the tissues of the human body and, when they enter a wound, multiply rapidly and attack the tissue cells with which they come in contact producing local redness, heat and swelling, the characteristic appearance of an infected wound. The pus of an infected wound consists of a combination of dead or damaged tissue cells, white corpuscles and germs.

Cleanliness is essential in the prevention of infection and everything thick comes in contract with the wound (hands and dressings) must be scrupulously clean. The hands are best cleaned by thorough scrubbing with soap, water (running if possible) and a nail brush, special attention being paid to the nails. Water may be rendered completely sterile only by boiling for 20 minutes.

Antiseptics are chemical preparations which have the power of restraining the growth of germs. They are commonly used in water soluble bases as antiseptic creams or in suitable solution as antiseptic lotions. Under the conditions in which first aid is given, the use of antiseptics is necessarily

© PMI, NTPC

253

limited. When however, medical aid is not readily available they may be used to cleans the skin round the wound.

General Rules for Treatment of Wounds Accompanied by Hemorrhage :

*

Place the casualty in a suitable position, bearing in mind that blood escapes with less force when the patient sits and still less when the patient lies down.

*

Elevate the bleeding part, except in the case of a fractured limb. Expose the wound, removing as little, clothing as possible

*

Do not disturb an blood clot already formed

*

Remove any foreign bodies which are visible and can be easily picked out or wiped off with a piece of clean dressing.

*

Apply and maintain pressure a)

direct

b)

indirect

*

Apply a dressing, pad and bandage

*

Immobilise the injured part. When the wound is near a joint immobilise the joint using splints if necessary, e.g., the knee.

INTERNAL HAEMORRHAGE Hemorrhage from an internal organ may result from injury, such as a crush, blow, fracture of a rib, of the pelvis or of the skull, or may be caused by a stab or bullet;

© PMI, NTPC

254

or it may be due to disease, in which case no external cause is apparent, internal hemorrhage may be •

Visible

•

Concealed.

Hemorrhage from an internal organ becomes visible in the following cases :•

Form the lungs - blood is coughed up. It is bright red and frothy.

•

From the stomach - blood is vomited. It sometimes has the appearance of coffee grounds.

•

From the upper bowel- blood is mixed with the motions and gives them a black tarry appearance.

•

From the lower bowel - blood in the motions is normal in appearance.

•

From the Kidneys - blood escapes with the urine which may be smoky or red in appearance. They may be-pain over the kidney areas.

•

From the bladder - blood is present in the urine which is often passed with difficulty.

Hemorrhage from an internal organ remains concealed in the following cases:•

Bleeding into the tissues associated with fractures.

•

Bleeding from the liver, spleen or pancreas takes place into the abdominal cavity and does not appear outside the body. This type of bleeding may be

© PMI, NTPC

255

very dangerous .and should be suspected where the signs and symptoms of hemorrhage are present following a crash or blow in the region of the liver, spleen or pancreas.

Signs and Symptoms •

Giddiness and faintness, especially when the upright position is assumed. Pallor of the face and lips. Cold clammy skin.

•

Thirst which may be severe.

•

Restlessness, the casualty may be excitable and talkative.

•

The pulse becomes progressively weaker and more rapid and may not be felt at the wrist.

•

The breathing may be hurried and laboured and accompanied by yawning and sighing.

•

Air hunger, i.e., distressed efforts to breathe; the casualty may throw his arms about, tug at his clothing and call for air.

•

Unconsciousness,

These signs and symptoms are, of course, present when the bleeding can be seen but with an external wound or visible internal hemorrhage there may be no need to note them in order to make a diagnosis. They may all be present in cases of established shock but air hunger, severe thirst and restlessness are indications the concealed bleeding is continuing. The condition is extremely dangerous and must receive priority.

© PMI, NTPC

256

Treatment •

Remove the casualty to hospital at the earliest possible moment. A note should be attached to the casualty that internal hemorrhage is suspected.

•

Do not give anything by mouth.

ASPHYXIA What is Asphyxia?

When the lungs do not get a sufficient supply of fresh air vital organs and the important nerve centers in the brain which regulate their activity are deprived of oxygen and this causes a dangerous condition called Asphyxia. Unless the cause is speedily removed and the supply oxygen restored to the blood circulating through the lungs, loss of consciousness, cessation of breathing, failure of the circulation and death will occur.

Causes of Asphyxia

Causes affecting the Respiratory Tract. •

Fluid in the air passages as in drowning.

•

Harmful gases or fumes in the air passages, e.g., coal gas, motor exhaust fumes, after-dump, smoke, sewer gas, ammonia.

Note : Some gases affect the respiratory centres in addition. •

Foreign bodies in the air passages causing choking, e.g., portions of food, artificial teeth, vomited matter in the case of an unconscious person

© PMI, NTPC

257

(owing to failure of the action of the epiglottis), tongue falling back in the case of an unconscious person, blood collecting from a fractured jaw. •

Compression of the windpipe, e.g., hanging, strangulation or throttling.

•

Smothering, e.g., overlaying an infant, an unconscious person laying face downwards on a pillow.

•

Swelling of the tissues within the throat as a result of burns, scalds, corrosives, stings (wasp or bee), or from some diseases affecting the throat.

Causes affecting the Respiratory Mechanism : •

Pressure on or crushing of the chest resulting from accidents in mines, quarries, sand pits or demolitions, or from pressure in a crowd.

•

Spasm of respiratory muscles in the case of certain poisons, e.g., Strychnine, or diseases, e.g., Tetanus (lockjaw).

•

Nervous diseases causing paralysis of the muscles of the chest wall or the diaphragm, e.g., Poliomyelitis.

•

Electric shock.

Causes affecting the Respiratory Centres. •

Electric shock

•

Stroke by lightening

© PMI, NTPC

258

•

Poisons such as prussic acid and Morphine

•

Some gases.

Sings and Symptoms of Asphyxia : Early stages :•

Dizziness and weakness Shortness of breath Rapid pulse

•

Partial loss of consciousness

•

Swelling of the veins of the neck Congestion of the face with blueness of cheeks and lips.

•

These signs and symptoms may vary with the degree of asphyxia present.

•

The lips, nose, ears, fingers and toes are bluish grey.

•

Breathing intermittent or absent Pulse slow and irregular

•

Complete loss of consciousness

General Rules for Treatment of Asphyxia : •

Remove the cause if possible or the casualty from the cause.

•

Ensure that there is a free passage for air. In an unconscious person the tongue may fall back and obstruct the air passages. This possibility should be kept constantly in mind if the casualty is lying on his back.

•

Apply artificial respiration immediately. Every second counts.

© PMI, NTPC

259

•

Artificial respiration must be continued until natural breathing is restored, if necessary for a long time unless a Doctor decides that further efforts will be of no avail. •

Utilise any help available to :-

o Provide warmth, e.g. blankets

o Provide shelter from the elements.

ELECTRICAL INJURIES Severe injury may be caused by the passage through the body of an electric current. This may be due to contact with a live and naked wire, cable or rail or from a stroke of lightening. The immediate effect is shock which may be relatively mild or so severe as to cause death (electrocution) depending on the strength of the current and on the path it takes in passing to earth through the body. Another result is burning and the burns may be severe and deep, especially with higher voltages.

Electrical injuries may occur :•

In houses and offices, from domestic apparatus with voltages up to 450 (alternating current).

•

In factories from equipment with voltage as high as 1,100 (alternating current).

•

Contact with a live rail - voltage in the region of 1,000 (direct current).

© PMI, NTPC

260

•

From overhead lines with high voltages of well over 100,000 (alternating current).

•

From lightening where the strength of the current is immeasurable and the voltage may be many millions e.g., standing under trees or in contact with metal railings or golf clubs.

Alternating currents are more dangerous than direct currents as the muscles are thrown into spasm causing the casualty to remain fixed in contact with the current. Moisture is a powerful conductor of electricity and when present, will facilitate the passage of the current. If the skin at the point of contact of earth is wet even the lower voltages may be dangerous. More important than the actual strength of the current is the path it takes through the body in finding its way to earth. Thus a very strong current passing to earth through the lower limb might be less dangerous than much weaker current crossing the chest, as unfortunately it is likely to do if it enters through 4he hand and arm. In these cases there may be immediate fatal paralysis of the heart and circulation escape, the heart may continue to function even though the breathing has stopped. It is for this reason that in electrical injuries the face is blue asphyxia) rather than white and that artificial respiration may have to be carried on for a very long time. As long as the heart beats life may be saved.

Treatment

Electric injury is an emergency calling for prompt and intelligent action - prompt action if the casualty's life is to be saved; intelligent action if two casualties instead of one are to be avoided.

Switch off the current. If the switch cannot be found immediately and the supply is through a flexible cable the current may be cut off by removing the plug or

© PMI, NTPC

261

even breaking the cable or wrenching it free. Do not attempt to cut cable with a knife a scissors.

If it is impossible to switch off or break the current remove the casualty from contact with the current. The greatest care is necessary; insulating materials must be used and they must be dry. With ordinary domestic apparatus rubber gloves are good and dry cap, coat or other garment or a folded newspaper gives fair protection. If possible the rescuer should stand on some insulating material such as rubber-sole shoes or boots or piles of newspapers.

With very high voltages, e.g., overhead lines, danger may exist even if the casualty is not actually in contact because the current may jump the gap (arcing). In these cases the rescue should, if possible, be left to a properly trained electrical man although there is no danger if the current is switched off. If expert help is not available, approach with great caution and keep as far away from any part of the electrical equipment as possible. Drag the casualty away with some no-conducting implement such as a dry walking stick, a dry board or a dry rope.

Unless the casualty is breathing normal - give artificial respiration, for some hours if necessary.

Treat for shock.

Treat any bums.

Transfer to hospital or seek medical aid.

Even after apparent recovery the casualty should be seen by a doctor to ensure that all is well as casualties suffering from electrical injuries are liable to relapse even when the effects have seemed to be mild.

© PMI, NTPC

262

ARTIFICIAL RESPIRATION ("HOLGER NIELSEN" METHOD) "Whenever Artificial Respiration is indicated, lose no time - every second counts."

Turning •

If the casualty is lying on his back turn him to the prone position (face downwards) as follows. Cross his far leg over the near leg.

•

Go down on the left knee opposite the casualty's head, placing the right foot on the ground out to the side.

•

Place the casualty's arms carefully above his head, and keep them there during the turn.

•

Grasp his right upper arm and turn him over, protecting his face with the other hand. Adjust the position of the casualty's hands as instructed below.

•

The above instructions can be reversed if necessary.

Position of the Casualty •

Lay the casualty in the prone position on a flat surface.

•

Place the casualty's hands one over the other, under his forehead. The head must be turned slightly to one side. The nose and mouth must be unobstructed.

© PMI, NTPC

263

Position of the Operation •

Place one knee with the inner side in line with the casualty's cheek six to twelve inches from the top of his head.

•

Place the other foot with the heel in line with the casualty's elbow.

•

Place the hands on the casualty's back with the heel of the hands on the lower part of the shoulder-blades, the thumbs alongside the spine, and the fingers pointing to the casualty's feet. (Fig. 6).

Movement (1)

Keeping the arms straight rock gently forward until the arms are vertical or almost vertical depending on the build of the casualty or that of the operator, using no special force. The movement takes 2 seconds counting "one, two". This pressure causes expiration. (Ref. Fig. 7).

© PMI, NTPC

264

Movement (2)

The operator now rocks back counting "three" for one second and slides his hand past the casualty's shoulders until they can grip his upper arms near the elbows. (Ref. Fig. 8) He raises and pulls on the arms until tension is felt 'for a period of 2 seconds counting "four, five". He should take care not to raise the chest from the ground.

This movement causes inspiration. The operator's arms should remain straight for the whole period. (Ref. Fig. 9).

© PMI, NTPC

265

Counting "six" for one second the operator lowers the casualty's arms to the ground and replaces his hands in the original position. The whole operation occupying 6 seconds (that is ten times a minute) should be rhythmic in character and be continued until breathing recommences. When the casualty begins to show signs of breathing the operator should continue with movement 2 only, raising and lowering the arms alternatively counting 1,2 (2 seconds) for Inspiration and 3,4 (2 seconds) for Expiration.

Summary of Counting Timing

The counting and timing are as follows : •

One - Two (2 seconds) - back pressure.

•

Three - (1 second) - sliding hands to arms.

•

Four - Five (2 seconds) - raising arms.

•

Six - (1 second) sliding hands to back.

The total count occupies six seconds which is ten times a minute. Opinions vary regarding methods of counting and timing.

It is, however, considered easier for the student to keep to a regular rhythm based on "the second" and for this reason the above method has been adopted in this manual.

INJURIES TO BONES AND JOINTS (FRACTURES) "Fracture is the term. used to indicate that a bone is broken or cracked."

© PMI, NTPC

266

Causes of Fractures Fractures may result from a variety of causes of which the most common is some form of force or violence. •

From direct force, when the bone breaks at the spot where the force is applied, e.g., from a severe blow, impact of bullet, crush by a wheel, result of a fall.

•

From indirect force when a bone breaks at some distance from the spot where the force is applied. In such cases force is transmitted along the intervening bones which may themselves escape injury, e.g., fracture of the collarbone may result from a fall on to the outstretched hand.

•

From the force due to muscular action, e.g., the knee cap is occasionally broken by a sudden violent contraction of the muscles attached to it.

•

Fractures are occasionally caused by a combination of direct and indirect force, e.g., fracture of the ankle as a result of a twist.

Types of Fracture

Fracture may be classified as: •

Simple or Closed - when there is no wound leading down to the broken bone. (Fig. 10)

•

Compound or Open - when there is a wound leading down to the broken bone or when the fractured ends protrude through the skin, thus allowing germs to obtain access to the site of the fracture. (Ret. Fig. 11)

© PMI, NTPC

267

•

Complicated - when there is associated injury to some important internal structure such as brain, spinalcord, nerve, lungs, liver spleen, kidney, major bloodvessel, or when a fracture at a joint is associated with a dislocation. A complicated fracture may be either simple or compound.

There are other varieties of fracture-hich cannot normally be diagnosed by the First Aider. These include :-

*

Comminuted

When the bone is broken into several parts.

*

Impacted

When the broken ends are driven into one another.

*

Greenstick

In the case of children the bone may be cracked and bent without breaking comoletely across.

© PMI, NTPC

268

*

Depressed

When, in the case of a fracture of the upper part or sides of the skull, the broken part of the bone is driven inwards.

General Signs and Symptoms of Fracture : •

Pain at or near the seat of fracture. Tenderness of discomfort on gentle pressure over the affected area.

•

Swelling about the seat of fracture. Swelling frequently renders it difficult to perceive other signs of fracture and care must be taken therefore not to treat the condition as a less serious injury.

•

Deformity of the limb; the limb may assume an unnatural position and be misshapen, The contracting muscles may cause the broken ends of the bone to override, thereby producing shortening of the limb.

•

Irregularity of the bone. If the fracture is near the skin the irregularity of the bone may be felt.

•

Crepitus (bony grating) may be heard or felt.

•

Unnatural movement at the seat of the fracture.

The last two signs should never be sought deliberately, but they may be noted during examination.

Any or all of these signs and symptoms may not be present: those which are may vary in degree.

Comparison with the uninjured side will assist in the diagnosis.

© PMI, NTPC

269

In addition to these signs and symptoms, marks on the clothing or skin may serve to locate the fracture. The snap of the bone may have been heard or felt.

General Rules for Treatment of Fractures

Treat The Fracture On The Spot

No attempt must be made to move the casualty until the injured part had been immobitised unless life -is in immediate danger from some other cause. If however, circumstances are such that final immobilisation cannot be completed on the spot, sufficient temporary fixation should be carried out to enable the casualty to be moved for a short distance to more suitable and safer surroundings. Hemorrhage and severe wounds must be dealt with before continuing with the treatment of fractures with due regard to the requirements of both types of injury.

Steady and support the injured parts at once, so that movement is impossible. This prevents further injury and any increase in the bleeding which always taken place at the site of the fracture. It also prevents the broken ends of the bones from damaging blood-vessels, nerves or muscles or piercing the skin.

Immobilise The Fracture •

By the use of handages and/or

•

By the use of splints.

The application of bandages, using the casualty's body as a means of support, will prove adequate for normal purposes. The additional support of splints may be required when there is the possibility of long or difficult transport before medical aid is available. Splints will also be required in those cases in which the

© PMI, NTPC

270

casualty's body cannot be used as a "natural splint," e.g., when both lower limbs are fractured.

If there is any doubt treat as a fracture and bear in mind that there may be more than one bone broken.

FRACTURE OF THE SPINE The spine may be broken either by direct or indirect force. Examples of direct violence are the fall of a heavy weight across the back, or falling from a height on the back across a bar, Causing fracture at the side of the impact. Examples of indirect force are a broken neck which may result from a fall on the head, and fracture in the lumbar region due to sudden over-flexion or jerking of the spine. A grave complication of fracture of the spine is injury to the spinal cord or to the nerves issuing from it. Such injury is caused by pressure from displaced body fragment or dislocation of vertebrae and results in complete or partial loss of power (paralysis) and/or sensation in all parts of the body below the side of the injury.

Fracture of the spine should be suspected in all cases in which there is a history of accident or injury to the vertebral column with pain and shock, even if there are no indications of paralysis. All cases of fracture of the spine must be regarded as serious emergencies and all doubtful cases must be treated as fractures.

Treatment of Cases of Spinal Injury : •

Immediately warn the casualty to lie still.

•

If the casualty is unconscious, ensure that breathing does not become obstructed by the tongue.

© PMI, NTPC

271

•

If medical aid is readily available :-

-

Do not move the casualty, but cover him with a blanket to ensure warmth and comfort.

-

Keep him under careful observation pending the arrival of medical aid.

•

If medical aid is not readily available :-

-

Place pads between the casualty's ankles, knees and thighs.

-

Apply a figure of eight bandage round his ankles and feet, the knot being tied under the soles of the feet.

-

Apply broad bandages round his knees and thighs over the intervening pads.

-

Make preparations for removal to shelter.

In all cases the casualty should be transported in the face upwards (supine), position. In certain circumstances, e.g. in coal mines, the face downwards (prone) position may be unavoidable but must not be used in fractures of the neck. It will assist the First Aider if he appreciates that the dangers resulting from moving the casualty are reduced to a minimum if the neck and/or trunk are not bent forwards (flexed), this being the movement which is most likely to damage the spinal cord.

© PMI, NTPC

272

DISLOCATIONS A "Dislocations" is the displacement of one or more bones at a joint. The joints most frequently dislocated are those of the shoulder, elbow, thumb, fingers and lower jaw, the last named resulting sometimes from yawning or a blow on the chin.

Signs and Symptoms •

Pain of a severe sickening character at or near the joint.

•

Fixity of the joint. The casualty cannot move the joint normally.

•

Deformity: The limb assumes an unnatural position and appears mishappen at the joint.

•

Swelling at the joint may occur.

•

In many cases it will prove difficulty or even impossible for a First Aider to distinguish between a dislocation and a fracture. Both may occur at the same time (Ref. Fig. 12).

© PMI, NTPC

273

In certain people, particularly epileptics, recurrent dislocations are common. These are practically painless, and so are frequently unrecognised. Careful enquiry into the previous history will assist in making a diagnosis in doubtful cases.

Treatment Do not attempt to reduce a dislocation. Obtain medical aid at once. •

In the case of limb

-

When the accident occurs out of doors, steady and support the limb and secure it in the most comfortable position using padding in order to lessen the effects of jolting during transport.

-

When the casualty is indoors, place the casualty on a couch or bed in the most comfortable position. Support the limb with pillows, cushions, etc.

•

In the case of the lower jaw

-

Remove any dentures. Support the lower jaw by a bandage tied over the top of the head.

-

The necessity for strict immobilisation in treating dislocations cannot be-4oo strongly stressed.

BURNS AND SCALDS A Bum is an injury caused by :•

Dry heat, such as fire, a piece of hot metal or the sun.

© PMI, NTPC

274

•

Contract with any object charged with a high tension electric current; or by lighting.

•

Friction, for example, by contact with a revolving wheel (brush bum) or fast-moving rope or wire.

•

Corrosive chemicals :-

*

Acids, such a sulphuric, nitric, hydrochloric.

*

Alkalis, such as caustic soda, caustic potash, strong ammonia or quicklime.

A "Scald " is an injury caused by moist heat, such a boiling water steam, improperly applied poultice, hot oil or tar.

Effects •

The effects of bum or scald are the same. There may be reddening of the skin or blister formation or destruction of the skin or destruction of the deeper tissues.

•

Pain is very severe.

•

There is immediate danger from shock which may be severe and made worse by the intense pain any by loss of plasma into the burnt area, Later there is danger from septic infection.

•

The areas of most bums and scalds, including the clothing involved, are to all intents and proposes sterile for a short period and every effort should be made to deep them so until medical aid is available. Prepared dry

© PMI, NTPC

275

sterile dressings should always be used if possible and great care must be taken in handling and applying them. •

The dangers of a bum increase with its surface area (even if it is only superficial) and if one-third or more of the skin area is involved, the patient may become dangerously ill. In small children and especially in infants even small burns should be regarded as serious injuries and medical aid sought without delay.

When a person's clothing catches fire, approach him holding a rug, blanket, coat or table cover in front of yourself for protection, wrap it round him, lay him flat and smother the flames. If a person's clothing catches fire when along, he should roll! on the floor, smothering the flames with the nearest available wrap and call for assistance; on no account should be rush into the open air. The use of fireguards will prevent many calamities in the home.

General Rules for the Treatment of Bums and Acalds : •

Avoid handling the affected are more than is necessary. See that your hands are as clean as possible by washing them.

•

Do not apply lotions of any kind. Do not remove burned clothing and do not break blisters.

•

Cover the area (including burned clothing) with a prepared dry sterile dressing if possible, otherwise clean lint, freshly laundered linen or some similar material may be used.

•

Bandage firmly except when blisters are present or suspected, in which case bandage lightly.

© PMI, NTPC

276

•

Immobilise the affected area by suitable means.

•

Treat for Shock.

•

In a major, case, remove the patient to hospital as quickly as possible. The casualty will probably require an anaesthetic, so that orally nothing should be given by the mouth. If medical aid is delayed for at least four hours, give drinks of water to which salt has been added in the proportion of half a teaspoon to two tumblers, with the addition of approximately half a teaspoon of bicarbonate of soda (if available).

•

In a minor case, give large quantities of warm fluids preferably weak tea sweetened with sugar.

•

When the face is burnt.

-

Cut from a piece of clean lint, a dressing in the shape of a mask, with a hole for breathing.

-

Maintain in position by a bandage as for fractured jaw

Treatment of Burns Caused by Corrosive Chemicals :

In all cases speed is essential to prevent further damage.

When the corrosive is an acid :•

The roughly flood the part with water.

•

Bathe the part freely with an alkaline solution, such as two teaspoons (one dessertspoon) of baking soda (bicarbonate of soda) or washing soda

© PMI, NTPC

277

(carbonate of soda) in one pint of warm water. •

Apply the general rules for the treatment of burns but remove contaminated clothing as quickly as possible to prevent further injury. Take reasonable precautions against burning yourself with contaminated clothing.

When the corrosive is an alkali :§

If the bum is caused by quicklime, brush off any that remains on the part. Thoroughly flood the part with water.

§

bath the part freely with a weak acid solution, such as vinegar or lemon juice diluted with an equal quantity of warm water.

§

Apply the general rules for the treatment of burns, but remove any contaminated clothing immediately taking reasonable precautions.

UNCONSCIOUSNESS Common Causes of Unconsciousness •

Shock

•

Asphyxia

•

Poisoning

•

Head injury associated with injury to the brain causing concussion or compression.

•

Apoplexy

© PMI, NTPC

278

•

Epilepsy

•

Hysteria

•

Infantile convulsions

•

Effects of excessive heat

•

Diabetes, and Insulin overdose.

•

Fainting

•

Heart attacks

Less Common Causes of Unconsciousness •

These include a large number of Medical and Surgical diseases such as inflammation of the brain, etc. The diagnosis of these is beyond the scope of the First Aider but intelligent application of the "General Rules for the Treatment of an unconscious person" will enable him to render first aid in all cases.

•

In some causes of unconsciousness convulsions are present. These are spasmodic and involuntary contractions of the muscles of the body and limbs. They may be general, affecting the whole of the body or they may be limited to the limbs or one side of the body a convulsion is commonly known as fit.

© PMI, NTPC

279

General Rules for Treatment of an Unconscious Person : •

Ensure an abundant supply of fresh air and that the air passages are not obstructed. −

Remove from harmful gases or impure atmosphere. Open windows and doors.

•

−

Keep back crowds.

−

Remove false teeth.

If breathing has stopped or appears to be failing turn the casualty in the prone position and commence artificial respiration.

•

If breathing is not noisy lay the casualty on his back with the head and shoulders slightly raised and supported, and turn the head to one side. Be prepared to modify the position if breathing becomes difficult or obstructed.

•

If breathing is noisy (bubbling through secretions) turn the casualty into the three-quarter prone position. −

Support him in this position with a pad in front of the chest or draw up the upper knee.

−

If the casualty is on a stretcher, raise the foot of the stretcher to help to drain secretions from the lungs.

•

Undo all tight clothing about the neck, chest and waist.

© PMI, NTPC

280

•

Apply the special treatment for the condition that has caused the unconsciousness.

•

Wrap in a blanket but do not apply heat.

•

Do not leave the casualty until he has been placed in the charge of a responsible person. Keep a continuous and careful watch for any change in his condition.

•

Do not attempt to give food or fluids, while the casualty is unconscious. Remove him to shelter - as a stretcher case as soon as possible.

•

When the returns to consciousness moisten the lips with water. Unless an abdominal injury is suspected, sips of water may be given if he complains of thirst.

© PMI, NTPC

281