Ch-12 Fire Fighting

CHAPTER TWELVE FIRE FIGHTING 1.0

Introduction Telecom equipment is energized from supplies derived from public AC mains or departmental engine alternator. Fire may be caused by use of higher rating fuse for circuit currents of longer intensity than the rated capacity flowing through wires or appliances, sparking due to loose contacts at certain points in the electric circuits. It can also be caused due to over load when high current cause over heating of conductors, wires coming into contact with one another and causing short circuit or wires getting earthed due to insulation of wires getting damaged. Smoking in office, equipment room, and power room. Cable chambers, battery room, throwing of burning cigarette bits, due to storage of inflammable material without proper precautions may also cause fire.

2.0

Triangle of fire

2.1

We shall at this stage have a look at the triangle of combustion. The three essential factors for a fire are (i)

The combustible material or fuel

(ii)

Oxygen or air

(iii)

The ignition temperature or heat.

OXYGEN OR AIR 2.2.1 If any of above factors is missing, there can be no fire. The methods of extinguishing fire, therefore is reduced to (i)

Removal of the fuel or starvation

(ii)

Removal of the oxygen or smothering

(iii)

Bringing down the temperature or cooling. Page 85 of 99

2.3

Fire, like heat is spread by condition, convection and radiation. Conduction means transmission through solids, convection through fluids while radiation requires no medium of transmission. All direct flames and flying sparks can also be included under the terms radiation and these account for the majority of equipment fires in the department. A careful watch is very essential to prevent such fires.

2.4

Throwing quantities of cold water effectively quenches majority of fires. A pump is a handy device and a party of three or four trained persons can with this appliance, effectively put out even a major conflagration. Water can, however, not be used over oil fires and electrical fire fused in the case of oil fires, oil being lighter will be spread out and the water sinking to the bottom gets heated up flashes into steam and consequently expanding to about 1700 times, foams over with violent eruption. In the case of electrical fires, use of water on live electrical equipment’s wiring involves personnel risk due to shocks. Also it causes permanent damage to use the electrical insulation. In such cases sand is the most commonly used fire fighting material. The sand cuts the supply of oxygen to the fire.

2.5

In most cases of fire, however, the point of conflagration is not easily accessible. The fire fighting operations will have to be done from distance only. Handy chemical fire extinguishers are, therefore, stored at convenient places and this case readily be used for directing the jet of the extinguishing fluid against the fire. In chemical fire extinguishers, no fire extinguishing chemicals are discharged but the gas generated by the chemical action is used as a propelling agent.

3.0

Precautions against fire in Telecom Building.

3.1

Preventive Measures (i)

Fuses of correct type and size must only be used for replacement.

(ii)

Bare fuse wires of strands of copper wire should not be used to replace blown fuses.

(iii)

All mains supply fuses should be inside their covers or cartridges and should not be exposed.

(iv)

It is necessary that all alarms type fuses should have the correct color beads fitted on them. Only fuse wire of correct rating should be used for their repairs.

(v)

Resistance spools should not be used indiscriminately, without any regard to their capacity for heat dissipation. The heat dissipated must not raise the temperature of the resistance spool to such a degree as to cause fire.

(vi)

While considering the wattage of the resistance to be used, maximum current that may flow through it under fault condition should be taken Page 86 of 99

into account and not merely the current under normal conditions of operation (vii)

For all resistances above 2 watts dissipation ceramic Bobbin type resistance coils should be used.

(viii)

All connections should be firmly fixed and soldered wherever necessary.

(ix)

All jack strips should be properly fitted and strip fastener screws properly tightened.

(x)

All power leads, especially those carrying heavy current must have conductors of gauge, sufficient to carry safely the maximum amount of current that is likely to pass through time.

(xi)

The leads should be of the proper lengths with just a little length spare for repairs etc.

(xii)

Even for temporary repairs, unnecessarily long lengths of wire or the wire of gauge smaller than what is needed should not be used.

(xiii)

In manual exchange and auto switch room the passages round the switch boards or equipment tacks should be kept clear of combustible material like books, directories, files, bottles of oil mythelated and denatured sprit, oil, pieces of cable etc. as they are likely to assist in spreading of fire.

(xiv)

Smoking in switch room, power room, equipment room cable chamber, battery room, and MDF room should be strictly prohibited.

(xv)

Where it is necessary to use blow lamps in apparatus room, ensure that asbestos blanket 3’ X 3’ and a bucket of sand is ready. The lighting of blowlamp should be carried out away from the apparatus rooms.

(xvi)

Naked lights should not be used and may not even be stored in rooms.

(xvii) Avoid accumulation of dirty cotton waste and especially oily rags and waste in the power room. (xviii) Whenever electric soldering iron is in use a red pilot lamp must be in circuit. 3.2

Precautions to be taken against spread of fire in Telecom. Buildings (i)

Adequate arrangements for provision of fire fighting appliance should be made.

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(ii)

In addition to fire extinguishers, buckets with water or with sand should be provided according to requirement and care should be taken to see that the buckets do not remain empty 1and that they are not used as spittle box waste paper baskets.

(iii)

In large buildings, water hydrants and hoses may be provided and kept near the water mains together with proper connecting fittings and tools for the same.

(iv)

Fire alarm should be installed in the building.

(v)

A non-exchange direct fire emergency magneto telephone should be provided in all important telecom buildings for direct communication with the fire Brigade station.

(vi)

Proper maintenance of the Fire Extinguishers should be done. For proper maintenance of fire extinguishers, following points may be noted.

(vii)

(a)

They should be kept in good condition at all times and should always be kept in their appointed place.

(b)

They should preferably, be mounted on the walls.

(c)

A copy of the instructions for maintenance and use should be framed and hung at a prominent place in the building.

(d)

Each extinguisher should have a card, fixed near the mounting bracket showing the date of its supply and the date on which it was last inspected, repaired and refilled etc.

(e)

Type of fire for which the extinguisher is suitable, should be prominently and clearly indicated on the card to be fixed near the bracket to which the Fire extinguisher is attached i. e. fires, general fires, electrical fires. A sample of the extinguishers inspection card is given on the next page.

In large telecom building smoke detectors may be installed in each and every room and even in corridors. These should be centralized alarm near the gate of the main entrance to the building. In case of detection of smoke the receptionist not only should get audible alarm (which should be loud enough for all the persons working in the building to hear). But he/she should also get a visual indication. On the fire alarm panel indicating the affected floor of the room, so that the fire is nipped in the bud.

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FIRE EXITINGUISHERSS INSPECTION CARD Fire Extinguisher No………………………………………… Type ……………………… ……. …………………………………………… Date of Installation ………………………………………………… Date Remarks On Initials with Date Date Remarks Checking Checking

on Initials Date

with

4.0

Fire Alarms

4.1

There are two types of fire alarm systems, which may be provided in Telecom. Building. (i)

Electrically operated system

(ii)

Manually operated system Electrically operated system consists of a number of indicator boards mounted at various places in he building to show the location of the fire. Fire alarm buttons are located also at various places of the building and when pressed cause the fire alarm bells to ring. At the same time, the position where a fire alarm button has been pressed is Page 89 of 99

shown on the indicator boards by the glow of the lamps. In every large building there may be 2 sets of bells and button switches. (a)

One for preliminary alarm to start fire fighting

(b)

And other clear out alarm to vacate the building if fire becomes hazardous.

4.2

Where the electrically operated fire alarm system is not provided, or where the fire alarm bell is not likely to be hard, fire rail bells are provided.

5.0

Frequency of testing of different fire fighting equipments. Frequency of testing of different fire fighting equipments is given below Sl.No.

Item

1.

Fire telephone

2.

Fire Extinguishers

Monthly

3.

Fire Drill

Monthly

4.

Fire Alarms

Weekly

6.0

Fire Fighting in Telecom. Buildings

6.1

Fire fighting Organization.

Frequency Daily

In order to adequately fight a fire and to control the staff of the building, a firefighting organization should be set up for each building. A list of officers and officials constituting the fire-fighting organization should be displayed in each floor. The different categories of fire fighting personnel are indicated below. (a)

Fire fighting officer: - The officer-in-charge of building will usually are the fire-fighting officer.

(b)

Floor wardens: - On each floor, a responsible officer usually the senior most Supervisor is appointed as a floor warden.

(c)

Asstt, warden: - the wardens under intimation to the fire fighting officers select them. They are to act as wardens in the absence of wardens for the floor.

(d)

Fire fighters: - Normally all engineering staff and other selected officials on duty are fire fighters. On the floors, used for administrative offices where no engineering staff is available, a group of fire fighters is selected by the floor wardens concerned in consultation with the sectional in-charge.

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6.2

Action to be taken in the event of fire.

6.2.1 Procedure during office hours The procedure of action to be taken in the event of a fire during office hours is given below.

(a)

Action by the person perceiving the fire: - As soon as the person perceives a fire, he should immediately press the nearest fire alarm button till it lacks or rings the fire alarm bell. Where electrical system is not provided then shout for attracting attention and help of others. If he is a fire fighter, he should fight the fire to the best of his capabilities after first sounding the alarm.

(b)

Action by the floor wardens: - On hearing the fire alarm bell, the warden of the floor affected must take charge and fight the fire with the help of fire fighters of his floor. Immediately the fire-fighting officer of the building should proceed to the scene of the fire and take the overall control. The fire fighting officer or in his absence, the floor warden will arrange to intimate the fire brigade headquarters over the direct or normal telephone line. The supervisor in the special service (auto manual exchange) should also be informed. The wardens of the floor affected, to ascertain if extra help is required. When it is already known that there is limited number of staff in the floor affected, the wardens of other floor should rush with fire fighters and fighting equipments of their floors immediately on hearing the alarm. The wardens will also send on representative to intimate the wardens of any such room, where the fire alarm bell is not likely to be heard about the occurrence of the fire. This is to ensure that no one in the building if left unaware of the starting of the fire. The wardens will also arrange to ring the rail bell if provided on their floors. In absence of a warden, the senior most, among the fire fighters will carry out the above duties.

(c)

Action by the fire fighters: - On hearing the fire alarm bell, all fire fighters will determine from the indicators board (where provided) whether the fire is on their floor or not. If the fire is on their floor, they must rush to the scene of he fire with extinguishers, etc, and fight it under the guidance of the floor wardens or the fire-fighting officer. If the fire is not on their floor they should put themselves in readiness and wait for the instructions of their floor warden if it is known that the floor warden or Asst. Warden is not present at that moment, all fire fighters will immediately proceed to fight the fire under guidance of the senior most member.

(d)

Action by traffic Operators in special service exchange. The trafficofficer in-charge on duty in the A/M room should immediately arrange Page 91 of 99

to ring the fire brigade on the direct line and arrange to intimate all senior departmental officers in the quickest time (e)

Action by the watchman: He will keep his position at the main entrance and intimate in the arrival of the Fire Brigade officer the place of fire. Entrance of all unauthorized persons, including callers for the P.C.O should be stopped.

(f)

Action by the air-conditioning staff: On becoming aware of the occurrence of the fire, the air-conditioning staff on duty should stop all blowers for the air-conditioning plant.

(g)

Action regarding water pumps: As soon as the fire alarm is heard, the water pumps should be immediately started to have constant supply of water in the over head tanks and fire hydrants where provided. This responsibility should be fixed on some suitable officials in advance, in the absence of whom; the fire-fighting officer will detail a person to carry out the job.

(h)

Action regarding motor vehicles in he garage: All vehicles are to be taken out of the garage away from the building. This should be done as quickly as possible and in such a fashion as no obstruction to the fire brigade vehicles is caused. The motor mechanic or driver will be responsible for seeing that this is done.

(i)

Action regarding telephone power plant: The telephone power is not to be disconnected, unless the fire is out of control, or the fire is originated in power equipment.

(j)

Action regarding fans in non-air-conditioned rooms: All fans are to be stopped immediately and windows closed.

(k)

Action regarding Mains Power: The mains power is not to be disconnected unless it is itself affected or the fire is out of control and clear out alarm is given.

(l)

Action by fire fighters when the fire brigade arrives: The controlling officer will hand over the charge to the fire brigade officer and withdraw the fire fighters who will continue to be present outside as stand by.

(m)

Action by liftman: Where more than one lift has been installed, the Liftin-charge will allot one lift for the exclusive use of the fire brigade party and make it non-available for regular traffic. Where only lift is provided, the same should be reserved for fire brigade party.

(n)

Action by the responsible floor warden after fire is extinguished by the fire fighters/fire brigade: The floor warden concerned should inform all other floor wardens that the fire has bee

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Extinguished. He will also ring up the special service supervisor for passing the information to all responsible officers. (o)

Action on hearing clear out alarm: The clear out bell where provided will be sounded or verbal orders shouted by the Officer-in-charge at any time he considers that there is any chance, whatever of personal danger to staff working in the building. He will of course consider the advice of the senior fire brigade Officer, if present. On hearing the clear out alarm, all the staff should assemble in an orderly manner and should walk out of the building to the open air. The warden will instruct as to which route would be followed in clearing out of building. The Officer-in-charge of sections will be responsible for seeing that the essential records are out of the building, In particular the attendance register. He should see that each official of the section is accounted for. Visitors to a particular section will be the responsibility of the section concerned.

6.2.2 Action after Officer hours. The following action should be taken in the event of fire after office hours. On hearing fire alarm, all firefighters present in the building will rush to the place of fire and fight it. The senior-most member on duty will take the control. The fire brigade must be intimated immediately over the fire emergency telephone. Special Service Supervisor should be informed for intimating all senior officers. He will make over the charge to the fire brigade officers when they arrive. He will then ring up the Exchange engineer or D.O.E to give a full report. In the case of small fire also al full report is to be given after it has been extinguished, all other actions will be as during office hours. 6.3

Training

6.3.1 All the staff including drivers of departmental motor vehicles should be given initial training in fire fighting. The assistance of the local Fire Brigade or the local Civil Defence Organization should be obtained for training the staff in fire fighting. 6.4

Fire Drills.

6.4.1 Monthly Fire Drill shall be held in which, as many members of the staff as possible, should attend. The Fire drill should be carried out in the presence of the Officer-in charge that should satisfy him that the staff is fully acquainted with the use of fire fighting appliances, fire telephone water pumps and the positions of main fuses or circuit breakers (Battery and Mains) and the action to be taken on the outbreak of a fire. If an inspecting officer is in the station at the time of Fire Drill or fire exercise, he should supervise the same and give suitable instruction. A surprise “Fire alarm” should be given once in six

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months, preferably when an inspecting officer is present, and any defects noticed in the working of the arrangements should be corrected. 7.0

7.1

Types of Fire extinguishers Soda acid type Foam type CO2 Type Provision of fire Extinguishers in Telecommunication building

7.2.1 The total area of the building should be divided into three parts as follows. (a)

Floor area used for offices, record rooms, general stores rooms, recreation room, canteen, and similar general purpose.

(b)

Floor area of storeroom used for stocking telecommunication equipment.

(c)

Floor area of rooms in which telecommunication equipment has been installed for use.

7.2.2 For the area at item (a) above, soda-acid type fire extinguishers should be provided at the rate of one per 250 sq. meters with a minimum of two per building. Also one water bucket per 250 sq. meters should be provided. The units should be placed at easily accessible points like corridors or near doors etc. 7.2.3 For areas at item (b) and (c) above, carbon dioxide type fire extinguishers should be provided. On very small fire where the flame is just started, carbon dioxide type of fire extinguishers is quite effective. If the fire appears to be uncontrollable, water should immediately be splashed from the buckets. The provision will be 2 fire extinguishers of Carbon dioxide type-two water buckets and two sand buckets per 100 sq meters of floor area with a minimum of two each in a building. In a closed space or air conditioned rooms carbon dioxide type of fire extinguishers will be installed. 7.2.4 There are certain equipment rooms like power rooms where oil filled equipments are installed or store rooms in which highly inflammable materials like oil, petrol, coal, etc, are stored. For, such rooms, it is necessary to have foam type of fire extinguishers, which cover up burning oil or petrol with a layer of foam. One extinguisher per 100 sq-meters of floor area should be provided, in addition, to the extinguishers mentioned above, for such rooms of extra hazards. 7.2.5 A statement showing different types of fire extinguishers, their characteristics and standard for provisions is given in table. Also typical instructions for maintenance of these fire extinguishers as given by some of the manufacture given in para 7.3. If extinguishers of any other make are purchased, the Page 94 of 99

maintenance instructions given by the manufacturer should be followed and exhibited in the building. 7.2.6 In addition to fire extinguishers and buckets, large multistoried buildings should have adequate provision of water hydrants and hoses. These can be arranged in consultation with local fire brigade authorities.

Fire Risk Expected

Place

Type of Fire possible

1. Light hazard

Rooms used for Administrati ve & general officer

Burning wood, Textile, paper, general domestic risks, chimney fire

2. Average hazard (Stores )

Store rooms containing dry goods, spare telegraph or telephone instruments & Spare parts insulated cables,

Burning wood textile, telegraph, telephone & electrical spares, etc.

Type of Fire Extinguishe rs Soda Acid (9 Liters

Normal Requireme nts One per 250 sq. meter with a minimum of 2 per building with 2 square refills each. Also I water Bucket kept ready filled.

Units shall be so located that a person will not have to travel more than 40 meters from any point to reach the nearest unit.

CO2 type of 4.5 Kg. capacity.

Two CO2 type per 100 sq. meter with a minimum of 2 per building 2 water and 2 sand buckets all ready & accessible for use.

Units shall be so located that a person will not have to travel more than 20 meters from any point to reach the nearest

Remarks

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electrical stores etc. 3. Average Open & hazard well (Technic ventilated al ) telephone exchange, carrier repeater & terminal stations, trunk exchanges & telegraph switch room, power rooms etc.

unit. Burning of CO2 type electrical of 4.5 Kg. apparatus, Capacity high and low tension arching, etc.

Two CO2 type per 100 sq. meter with a minimum of 2 per building & 2 water & 2 sand buckets all ready and accessible for use but kept outside equipment rooms 4. Average Air Burning of COS type 2 per 100 hazard Conditione electrical fire sq. meters (Techni d or poorly apparatus, extinguishe with a cal) ventilated high and rs of 4.5 minimum of in Airequipment low tension Kg. 2 per conditio or store wiring etc. Capacity building ned rooms also 2 rooms water & 2 sand buckets but kept outside equipment rooms

Units shall be so located that a person will not have to travel more than 20 meters from any point to reach the nearest unit.

Unites shall be so located that a person will not have to travel more than 20 meters from any point to reach the nearest unit.

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Fire Risk Expected 1. Extra hazard

Type of Fire possible

Type of Place Fire extinguishe rs Store Burning oil, Foam type rooms petrol, 9 liters containing grease, highly paints, inflammabl spirit, oil, e materials, engine, oil, petrol, coal etc. coal etc, power rooms with oil filled equipments engine generator rooms HT switch board rooms etc.

Normal Requireme nts 1 per 100 sq. meter with a minimum of 2 per room with 4 spare refills for each extinguishe r. In addition to extinguishe rs buckets as per item 2 or 3 or 4 above.

Remarks Units shall be so located that a person will not have to travel more than 20 meters from any point to reach the nearest unit.

Note : Capacities indicated above are approximate and manufactured capacity may be used. The buildings will also have adequate arrangements for water supply hydrants and hosepipe in cabinets ready for use.

7.3

Maintenance Instructions of Fire extinguishers The maintenance instructions for different type of fire extinguishers are given below. (i)

Remove the extinguisher from its bracket and unscrew the cap.

(ii)

Inspect the cap washer and if perished renew. Apply grease to spindle, cap and threads.

(iii)

Remove acid bottle carefully.

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(iv)

Stir the soda solution and if the level is below that indicated, add fresh water, after two years, the solution should be renewed.

(v)

Replace acid bottle carefully with point down ward, screw cap or tightly with the spindle pulled out to its full extent.

(vi)

See that the nozzle is clear of any foreign matter by inserting a piece of wire.

(vii)

Examine the outside of the extinguisher to see whether it is corroded and requires repainting. If there is any hole in the container, the extinguisher, is useless and must be replaced.

7.3.2 Foam Type (i)

Remove the extinguisher from its bracket and unscrew the cap. If the cap dies not unscrew easily then: Tap round with wooden mallet, and apply grease to threads to enable the cap to be easily removed.

(ii)

Remove the inner container without spilling any of the solution into the outer body. Examine inner container for sings of corrosion. Examine inner visible part of outer container for signs of corrosion.

(iii)

Test the two solutions by mixing a teaspoonful of the inner container liquid with a teaspoonful of the outer body liquid. The resulting foam should immediately increase to 8 times it volume. If it does not, then the solution must be removed.

(iv)

If the existing solutions are in good order then each solution should be aerated by stirring in its container.

(v)

Inspect all working parts and renew rubber washers and springs if necessary. Grease springs and apply grease to the threads.

(vi)

Test the springs of the cap by screwing the cap several turns on to the body and make sure that the bayonet joint fits.

(vii)

Replace the inner container carefully and screw down with the handle in the “Open position”. When the cap threads are tight, turn the handle to “Closed position”

(viii)

See that the nozzle is clear by introducing a piece of wire.

(ix)

Examine the outside of the extinguisher is to see whether it is corroded. If there is any hole in the container the extinguisher useless and it must be repaired or replaced.

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(x)

Replace the extinguisher to its stand. Check that the number on the extinguisher corresponds with the number on the brackets.

(xi)

Fill up form, which is displayed with the extinguisher.

7.3.3 CO2 Type These fire extinguishers should be weighed periodically every second or third month and the weight recorded. If the loss of weight is more than 10 to 50% the extinguishers may be recharged by sending them to the firm. Also according to the Explosive rules of the Government of India every cylinder is required to be tested hydraulically up to the pressure of 236 Kg, per sq. cm. every two years, for which they may be sent to the firm. 8.0

Reporting of Fires to the Higher Authorities

8.1

In all events of outbreak of Fire in Telecom. Buildings, the DGM of the Circle and the GM of T & D Circle, Jabalpur should be informed telegraphically. The DGM should inform the member services of the Telecom commission on telephone in case of serious interruption to communications or extensive damage to equipment.

9.0

Investigation as to the cause of the fire should also be carried out in every case without disrupting the service as per questionnaire given below The answers to all the questions in the questionnaire should be carefully obtained and recorded as evidence, in order to facilitate any further enquires into the causes of the fire at a later stage. The `General’ part of the questionnaire deals with the action to be taken by the officer (a technical officer or a traffic officer) on duty. The Engineering part of the Questionnaire is to be dealt with by the senior most Engineering Officer-incharge at the time of occurrence of the fire. A clear photograph of the damaged part of the equipment should invariably be taken prior to its replacement or repair. The damaged relay pates, fuse strips arrestor and heat coil strips, cables, jack strips etc. should not be thrown away, but must be kept under safe custody along with the written statements of all concerned by the senior most officer for conducting detailed investigations at a later stage.

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