I. ACCOMMODATION AND LIMITATION OF STOCK
1. In view of the high calorific value of rubber and the difficulty of fighting a rubber fire it is desirable that the storage should be confined to :
(i) Single storey buildings in which no other goods are stored;
(ii) Multi-storey buildings of fire resisting construction in which no other goods are stored on the same storey as rubber, which should where possible be confined to the basement, ground and first storeys;
(iii) Fire-resisting basements or vaults in which no other goods are stored.
2. Not more than 500 tons of natural synthetic or reclaimed rubber should be stored in any buildings or in any one fire resisting compartment of a building.
3. The building should not be exposed to an external fire hazard, nor should it present an exposure hazard to other buildings or open storage (for method of reducing exposure hazard see Section II).
II. EXPOSURE
1. There should be no windows or other openings in the external walls of the storage building within 10 feet directly or diagonally of any openings in the walls of another building. Window openings within 10 to 20 feet of openings in other walls should be fitted with fire-resisting shutters, or other equivalent protection and door openings with fire-resisting doors. Windows within 20 to 40 feet of other openings should be fitted with wired glass.
2. Openings in external walls of the storage building overlooking lower roofs (other than roofs of concrete without openings) of other buildings should also be protected as above.
3. Roofs of the storage building should have no glazed openings within 20 feet of any openings in an adajecent concrete roof or any peace of any other type of roofs.
III. HEATING LIGHTING AND POWER.
1. If storeys or compartments containing rubber are heated this should be by low pressure steam or low pressure hot water, with the boiler in a separate fire-resisting compartment entered from outside the buildings only. For the purpose of these recommendations a low pressure steam heating system is one working at not more than 15 1b. per square inch gauge pressure and a low pressure hot water system is one in which the gauge pressure at the boiler does not exceed 53 1b. per square inch;
2. Artificial lighting should be by electricity.
3. All electric wiring, except to portable lamps and equipments referred to below, should be in screwed steel conduit or be mineral-insulated copper sheated cable.
4. Flexible lighting pendants should not be used and portable lamps should be avoided if possible. If, however portable lamps are indispensable they should be fitted with substantial wire guards.
5. Flexible leads to portable lights and equipment should be tough rubber sheated and armoured, and connected to the supply and earthed by three-pin plugs.
6. Electrical wiring and equipment should be installed and maintained in accordance with the Tariff Advisory Committee “Regulations for the Electrical Equipment of Buildings.”
7. The main switches of all electrical circuits should be in the ‘of position when the electrical equipment is not in use.
IV. WARMING ROOMS AND CHAMBERS
The rooms and chambers forming part of warehouses in which a small number of bales for sampling are softened by heat should be separate fire-resisting compartments with a single fire-resisting door.
The boilers or heaters for the above heating systems should be in separate fire-resisting compartments entered from outside the building only.
Electric heaters with heating elements totally enclosed.
All heaters or pipes should be screened by stout fixed guards or so fitted that rubber cannot be placed within 12 inches of any heated surface.
V. STACKING
In order to control the spread of fire within a compartment and to ease the task of fire fighting it is desirable that the rubber should be stacked in the smallest piles practicable, with adequate gangways for access to the piles. The following are recommended :-
(i) Not more than 50 tons of rubber should be placed in any one stack or pile;
(ii) There should, wherever practicable, be a space of at least three fest between the coiling of the storage compartment and the top of the rubber stacks or piles, and there should never be less than one foot;
(iii) No stack or pile should be more than 10 feet high;
(iv) There should be a gangway at least three feet wide between stacks and where more than 250 tons are stored in any one compartment or undivided storey, there should be at least one main gangway and one transverse gangway each not less than eight feet wide across the compartment or storey.
VI. GENERAL
1. In the event of fire, call the fire brigade immediately an outbreak is discovered. Pending their arrival the fire should be attacked with the available fire appliances. There is no charge for the attendance of the fire brigade.
2. Notice instructing staff how to call the nearest fire brigade in case of fire should be posted at every telephone. The method of calling should be agreed with the chief officer of the local fire brigade.
3. Notices bearing suitable instructions to staff in case of fire should be prominently displayed in all compartments.
4. Naked lights, open fires and smoking should be prohibited except in ground floor compartments occupied as offices, messrooms or lavatories, which have fire-resisting walls and ceilings, and which do not communicate with any other part of the building and are entered only from outside the building. “No Smoking” Notices should be posted accordingly. Non-combustible receptacles for cigarette-ends, matches etc., should be provided in the rooms where smoking is permitted.
5. Petroleum spirit or other flammable liquids should not be kept in storage buildings.
6. Road vehicles should not be loaded or unloaded in buildings while the engines are running.
7. Where mobile petrol-driven mechanical handling appliances are employed :
(a) The fuel tanks should be permanently attached to the vehicles and so placed or guarded as to minimise the risk of damage;
(b) The exhaust system should be designed with adequate baffles and a vertical exhaust pipe;
(c) The petrol feed should be so designed and located that petrol cannot leak on to any heated surface;
(d) Fuel tanks should not be filled or emptied in the buildings. No petrol other than that carried in the tanks of
vehicles should be stored or used in the buildings;
(e) Each vehicle should carry a fire extinguisher of the foam or carbon tetrachloride type. (Carbon tetrachloride extinguishers should not be used in confined spaces on account of the toxic hazard).
8. No vehicles or mechanical handling appliances should be garaged in the buildings.
9. These storage buildings and surrounding premises should be kept clean and free from rubbish. Grass and undergrowth in the vicinity should be cut frequently and removed. Grass and weeds should in no circumstances be burnt off.
10. Fire-resisting doors and shutters should be kept closed whenever possible and always after working hours.
11. At all internal doorways there should be sills or ramps on either side at least two inches above the floor level to restrict the flow of water and molten rubber from one compartment, storey or building to others.
12. A routine inspection of the storage buildings should be made before they are closed.
VII. ACCESIBILITY
1. Roadways in the immediate vicinity of the premises should be sufficiently wide for the manoeuvring of fire engines, and gateways should be not less than 12 feet wide. There should be door and window openings on to a street or open space. (Advice on these points may be obtained from the Chief Officer of the local fire brigade).
2. Private roadway should be kept free from obstruction.
VIII. FIRE APPLIANCES AND ALARM EQUIPMENT
1. Water is the most efficient extinguishing medium for rubber fires.
2. Hose reels and soda acid or water (gas pressure) extinguishers should be provided for first-aid fire fighting.
3. Hydrant System must be installed in accordance with Tariff Advisory Committee regulations.
4. All persons employed on the premises should receive regular training in the use of the first-aid fire fighting equipment and in the method of calling the fire brigade.
5. Fire appliances should be kept in good order.
6. The installation of automatic sprinkler systems is recommended. They should conform to the rules of the Tariff Advisory Committee.
7. A fire warning system which can be heard by all on the premises is of value.
We will not discuss how the various hazardous features have been taken into account while arriving at the tariff structure (All India Fire Tariff). The tariff comprises three sections, one deals with the manufacturing of Crude Rubber and the other two which are included under General Tariff deal with the manufacture of rubber goods from crude rubber.
The usage of combustible materials like wood in the hot air system is prohibited by introducing a warranty which is reproduced below:
“Warranted that during the currency of the policy all chimneys and/or flues carrying off the products of combustion be of incombustible material and be kept in good state of repair and free from any wood work or other combustible material”.
The purpose for introducing this warranty is quite obvious.
Furnaces are normally used for heating purposes which are preferably located outside the factory or separated from the manufacturing block by solid wall of not less than 45.6 cms thick. The furnace is a source of ignition and if it is located inside the block any escape of sparks from the furnace will result in a fire. Hence, a warranty has been incorporated in the tariff which reads as under :
“Warranted that during the currency of policy the furnaces used for generating heat are situated outside the factory and separated from it by a solid wall of stone or brick not less than 45.6 cms thick through which only hot air is introduced”.
The tariff classification consists of three groups and the rate is in ascending order, that is factories where no smoking or drying by artificial heat is carried on, carry the lowest rate followed by factories where only heating is carried on. The highest rate is for factories where smoking is also carried on. The hazards are increased due to artificial heating and smoking by curing process. This has been dealt with in the earlier section of this chapter.
Rubber good factories are split into two groups, one deals specifically with Rubber tyres and tyre tubes Mfg. Premises and the other with all other Rubber goods Mfg. Premises. In the case of Rubber tyre and tyre tubes Mfg. Premises, rubber solution preparation room carries the highest rate due to the presence of highly flammable material like Naptha. Banburry Mill, Rubber Preparation Section, Fabric dipping and Coating Section carry the lower rate than the above section as the hazards are lesser. The hazards in the Banburry mill, Rubber preparation section, fabric dipping and coating section are due to the operation involving higher temperature, rotating machines and combustible materials like coal, sulphur, raw rubber etc. Tyre and tube building section carries the lowest rate as the hazards are comparatively less than the above two sections.
In the case of Rubber goods Mfg. Premises (other than Tyre & Tube Factories), the tariff provision is as follows:
Premises where no vulcanizing is carried on or where no solvents used carry the lowest rate. If vulcanizing is carried out, the rate is higher. Spreading carries the highest rate if Naptha is used in this section. The reason for splitting this into three groups can be inferred from the earlier sections i.e. the rate is in the increasing order due to the increasing hazards associated with the process.
The foregoing discussions about the tariff rating structure with the relevant warranties is only to highlight the various hazards involved since we are not concerned for the present purposes with the absolute rates. A case history of an actual loss is given as Appendix I to this lesson to enable the student to have an appreciation as how a fire has occurred in a Rubber Factory.