Mine Fire ism pptk jcifificuggigifigiv.pptx

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1. Fire Management in Mines Detection,Prevention,Dealing &Control etc. Surajit Mitter B Tech (Min),ISM Ex Chief Manager(Min), BCCL

2. Introduction Fire and explosion protection is very intensively practiced in coal mines as unlike most other branches of the mining industry, the mines produce a flammable product, coal and coal dust. Furthermore, during mining coal flammable fire damp (methane) enters into the workings, a factor which adds to the risk of fire and explosions.

3. MINE FIRES Combustible substances present in coal mines. First, coal itself, occurring naturally, is a very complex substance. Then follow those substances taken into the mine to make possible the operation of winning the coal. Timber which may be hard, as used for chocks, or soft, as used for props and bars. Bituminous substances such as brattice cloth , the insulation of cables , and conveyor belts. Oils and greases , as used for the lubrication of machinery or in the form of oils in switchgear and transformers.

4. Effect of the physical form on the rate of combustion. Generally soft woods burn at a higher rate than do hard woods, but it appears that the greater the surface area exposed in proportion to the bulk of the substance, the greater is the rate of combustion. As an example, brattice cloth burns at a high rate , and incidentally results in a dangerous degree of pollution of the atmosphere. Coal which is much fractured presents an increased surface area, permits access of air into the breaks and allows the development of deep-seated incandescence. With oils, combustion occurs at the vaporizing free surface , and is accompanied by free flaming and much smoke.

5. Characteristics of open, freely burning fires, Whilst the chemical process of combustion is the same in principle no matter where the burning take place, the effect of a fire occurring underground can be widely different from the effects of a fire involving the same combustible substances in the open atmosphere at the surface. Where coal is burning underground there will be free flaming in the early stages, accompanied by emission of large volumes of smoke and tarry vapours . On the return side of the fire this smoky atmosphere will have on oxygen content less than normal and will carry an increased carbon dioxide content, together with very poisonous gas carbon monoxide.

6. In every occurance of fire the actual degree of toxicity can be determined only by ascertaining the carbon monoxide, carbon dioxide and oxygen content by chemical analysis. Oils, bituminous compounds and rubber burn with free flame accompanied by the formation of large volumes of dense black smoke. Wood flames more or less freely as it is a soft or hard type, and in proportion to the surface area to volume ratio. Wood smoke is grayish in colour and it readily pains the eyes.

7. Development of open fires. In a mine road with high-velocity air currents, the conditions in respect of the combustion process approximate to those of chimney drought . Generally the higher the velocity of the ventilating air current, the higher will be temperatures attained and the greater the rate of fire-spread. This latter factor is itself influenced by the continuity of the combustible substances. Coal side, particularly if crushed and broken, timber closely set or placed longitudinally in respect of the road, elongated deposits of oil and grease, and rubber belt conveyors quite clearly give and unbroken fire path.

8. ORIGIN OF MINE FIRES The main causes of fires underground are spontaneous combustion of coal, arcing in electric installations, friction heat and fires in vehicles, shot-firing, contraband. 2.1 SPONTANEOUS COMBUSTION Some coals are able to set fire to themselves, especially after being crushed or broken up in some way. Gases contained in the pores of the coal are thereby allowed to escape and as they cease to do so, the absorption of oxygen from the atmosphere commences.

9. After the complex unsaturated oxygen compounds of the coal substance have taken up a certain quantity of oxygen, heat is generated by the continued oxidation process. The rate of heat generation is influenced by the fineness of division of the broken coal and the rate of oxygen absorption. The local conditions preventing heat escape, in the early stages of the heating, influence the rate at which the temperature of the oxidizing mass increases. It has been established that with increase of temperature of the mass there is an increase of the rate of oxygen absorption. Thus a cycle is established which continues until, finally, active combustion is set up.

10. it is readily deducted that there is an incubation period which will not be manifest to the natural senses, followed later by an indication period during which signs of heating will be evident. At a temperature in the oxidizing mass of about 120 degree centigrade, carbon dioxide and water vapour appear. The process then accelerate and there is a pronounced and decidedly characteristic smell of “gob stink”. Between 200 degree centigrade and 275 degree centigrade, a self sustained process of combustion is established, the temperature then rising rapidly to the ignition point of the coal.

11. A heating is fairly well established when condensation of moisture near the heating and the smell of gob stink are readily noticed . This effect sometimes occurs at the edges of coal pillars on the sides of roadways driven in the solid or where small ribs or pillars are left in the goaf, and where, in the working of thick seams, roof coal is left in the goaf. In such causes the coal is crushed to a fine state and offers conditions ideal for the development of spontaneous combustion.

12. It follows that before spontaneous combustion can occur two conditions are necessary. Firstly , there must be coal in a finely divided state, and secondly, the coal must be supplied with air or oxygen. Circulation of air through the fine coal dust, however, be limited, as if it is too brisk the heat is carried away, with the result that ignition temperature is not reached. On the other hand, the amount of air must be sufficient to supply the oxygen needed for oxidation or the fire will not develop. These conditions which tend to stimulate sponteneous combustion frequently exist in goaf unless proper precautions are adopted to prevent their occurrence. Obvious remedies against spontaneous combustion in the goaf are either to see that no coal is left therein or to prevent the access of air to any coal unavoidable left.

13. Air circulation in goaf can be prevented by proper attention to packing, and although many supplementary precautions are necessary, it is chiefly by this means that spontaneous combustion is prevented . All supports must be withdrawn from the goaf, so that the roof can settle, and good packs of non-inflammable material, forming effective air seals, must be employed. Special attention is necessary to the packing at rib sides, where the regular subsidence of the roof is interfered with by solid coal. For this reason rib-side packs are often sealed by the insertion of a layer of sand along the coal side and on top of the packing material.

14. Pneumatic stowing has been found to be an effective safeguard against gob fires. Based on the understanding of the above, some of the most important preventive methods against spontaneous combustion might be as follows : a.Coal seams should be sectionalized by panels. Worked out panels should be sealed off as soon as possible b.During extraction of pillars as complete as possible extraction should be done within the incubation period. c.Where coals has been left because of geological faults, such places should be hermetically sealed , especially where the seam itself tends to spontaneous combustion. No coal or coal shale should be stocked under ground or used in packing. All discarded and stripped roadways and drifts should be seals off. d.Thick seams should be extracted with stowing e.Special sealants or gunniniting for pillar sides and roadways should be employed.

15. FIRES THROUGH ARCING IN ELECTRICAL INSTALLATIONS 2.2 Fires may be caused by defects in electrical equipments . Amongst such defects are short-circuits and flash-over in motors and switchgear, insufficient or unsuitable oil in oilmmersed switchgear, transformers and resistances and defective insulation. Mechanical damage to cables, especially trailing cables, has resulted in a number of outbreaks of fire. Electric cables and conductors used underground have to continue functioning as long as possible when exposed to a fire in order to ensure the emergency supply of transport equipment, ventilation systems, fire detection systems, emergency calls and telemetering. Therefore, they are subject to certain fire safety requirements and approval by the mining authorities.

16. Some of the most important practical preventive measures that might be recommended and should be checked during inspections are the following: a.See that the electric cables are installed in safe situation ; b.Cables should be properly secured to the side of the working. They should not sag or be fallen to the ground and become buried in coal dust; c. Overloading or excessive voltage on cables should be avoided; d.Only approved type of the electrical equipment should be used in coal mines. Not combustible materials should accumulate on electrical equipment; e.Ensure proper functioning of overcurrent and earth leakage protection; f.The cooling arrangement of motors should be kept clean; g.Oil-immersed gears should be kept in good quality oil and correct level of the oil should be maintained; h.Motor, rooms should be built of incombustible material

17. FIRES IN VEHICLES In some countries coal mining increasely used load-dump technology, i.e. large diesel-driven trackless vehicles for loading and hauling, in addition to hydraulic drilling jumbos. Such vehicles carry sometimes several hundred liters of hydraulic liquid and diesel fuel. A break in a hydraulic hose under pressure or in the fuel like may release liquid on the heated parts of the combustion engine and inflame them.

18. IGNITION THROUGH FRICTION Many fires have been caused by heat developed by friction of ropes and belts. Thus, endless ropes rubbing on wooden pulley frames and other inflammable material have started fires in some cases. Conveyor belts have also developed sufficient heat to start fires in wooden props and supporting frames. Heated bearings due to improper lubrication and damaged rubber belts have also initiated fires.

19. The name frictional ignition is given to an ignition caused by a spark or a very hot area of stone produced by rubbing or impact during the winning of coal at longwall face or in a continuous miner heading. The gas liberated by the fragmentation of coal, or issuing directly form the seam, becomes ignited by heat resulting from the fast moving picks of the machine striking certain types of rock in the roof or floor or in the seam. The only two common minerals in collieries that can so produce an incendiary temperature are quartz and pyrites.

20. However, as mining is carried out by the cutting action of machine picks, it is impossible to eliminate frictional ignition entirely. Yet the number of picks must be kept to a minimum , and the standard of ventilation must be such that should any small ignition occur it will not develop into an explosion. Water sprays should be applied behind the picks of the coal cutting machines.

21. For preventing frictional ignition: a.Only fire resistant conveyor belts, brake lining, v.belts, brattices, and hydraulic fruits should be used. b.Timber can be rendered fire-resistant by impregnation. c.Oil grease, canvas etc. should be regularly removed or stored in proper receptacles. d.Belt conveyors should be set to line an away from timber supports. Check should be made for ceased bearings of conveyor idlers and drums. Proper tension should be applied to conveyor belts to avoid belt slippage. Conveyor bottom should be kept clear of coal dust . e.Haulage rollers and sheaves should be clean and coal dust and coal deposits should be removed in vicinity f. Sharp picks with water jets should be used at the sharers and road headers.

22. SHOT-FIRING Probably the greatest danger arising from the use of explosives is consequent of human element. The use of explosive in mines is carefully controlled by Regulations and the materials to be used are specified and prescribed with the view to safety. Ignitions occur due to the use of explosives. Cases have been recorded where burning fragments ejected from shot-holes have started fires, in other cases, flame from explosives has ignited firedamp in breaks, which has continued to burn for long periods.

23. Some of the most important practical preventive measures at shot-firing might be suggested : a.Only explosives and detonators approved by the competent authority and provided by the mine operator should be taken into or used in the mine; b.Explosives should be used judiciously to minimize chances of blow-outs and deflagration; c.Immediately before charging each shot and before firing, the shotfirer should test the air for firedamp with the radius to be specified in regulations ; d.When firing in the coal seams liable to produce dangerous dust, before charging the shots, the firing area should be adequately protected by stone dusting or watering.

24. DETECTION OF HEATING An essential requirement in mines liable to spontaneous combustion is the establishment of an organization for the detection and treatment of gob fires. Sensory indications . These fires emit a characteristic smell known as “gob stink”. It is followed by faint haze, sweating, discomfort of men (tickling in the nose, dry throat, increased secretion of saliva, dulling of sense, difficulty in walking). Specially trained men are able to detect the earliest stages of spontaneous combustion by this means. Subsidence cracks should be frequently inspected because stink usually appears there before its presence is detected underground. Underground workings should be kept clear of rotten timber, excess of lubricant, night soil etc. Also coal burning near downcast shafts or inclines should be prohibited.

25. HYDROMETIC AND TEMPERATURE READINGS Alternatively, analyses on the intake and return sides of a suspected area will give an indication of whether combustion is in progress or not. Development of heating is accompanied by progressive rise of temperature and humidity. Systematic records of dry and wet bulb readings of depillaring district might give indication of any heatings. Temperature recording may be useful for detection of any heating of coal pillars between intake and return airways after increase in watergauge, roadside packs, coal heaps, goaf by leaving thermocouples buried in goaf and remotely monitoring the temperature readings.

26. Chemical indications : The more scientific method of detection is by frequent and systematic air sampling and analysis. Regular and systematic analysis of return airway provides a reliable indications as to the development of heating in the district. It has been found that the ratio of the percentage of carbon monoxide in the air to the percentage of oxygen absorbed is a reliable index of the presence or absence of spontaneous combustion. This ratio, known as the CO/O 2 ratio, is constant/a given area of the mine, and if it is carefully watched the presence of combustion is known by its change. The ratio is determined analytically.

27. Nevertheless, fires are frequently detected earlier by the human nose than by the more scientific methods. These latter must, however, be used whenever there is danger, as they afford useful information regarding the rate of growing of the heating of fire.

28. Spontaneous Heating

29. SIGNS OF SPONTANEOUS HEATING a) Initial stage of heating: i ) Faint haze: This is due to moisture given off during oxidation of coal. The moisture collects as small globules in the cooler air away. ii) Moisture deposition : This is due to condensation of moisture and its deposition as beads on the cooler surfaces. iii) Faint odour known as gob stink : The odour resembles the smell of decaying timber . There is also slight discomfort due to increase in air temperature and humidity. iv) Cricket and other small insects show increased activity and chirping.

30. b) Intermediate stage: Previous symptoms are intensified and there is a further pronounced petrol-like smell indicating the beginning of distillation of coal. c) Last stage of heating approaching ignition : Petrol like odour changes in to tarry odour , known as fire stink which is also due to distillation of coal. Further stage is the actual appearance of smoke.

31. Factors Effecting Spontaneous Combustion The factors are as follows. 1) Presence of Iron Pyrites – promotes spontaneous heating 2) Area of coal surface - greater the area more chance of sp. combustion 3) Freshness of exposed coal surface – rate of oxidation increases with time 4) Rank of Coal - low rank coals are more susceptible to the sp. heating 5) Volatile content - Oxidation rate increases with volatile content 6) Petrographic composition of coal - vitrain and clarain increases 7) Oxygen content - Oxidation decreases with decreasing O2 percentage

32. 8) Moisture content - High moisture more susceptible to self-heating 9) Temperature of Atmosphere - Warm air increases the oxidation 10) Ash content - Ash in coal generally decreases the oxidation rate 11) Influence of Rock Pressure - Rock pressure increases oxidation 12) Ventilation - Weak air current helps to oxidation 13) Friability – Broken smaller size coal is more liable to self-heating 14) Nature of Adjoining Strata – Conductivity of adjoining strata effects.

33. 15) Depth of seam - increases in temp with the depth, accelerate self-heating. 16) Thickness of seam – It increases the chance of spontaneous heating. 17) Geological disturbances - fault plane coal is crushed & is more liable to self- heating. 18) Time factor – After certain time, the first signs of heat appear. 19) Method of working – affects self- heating. 20) Leakage of air - leads to self heating of coal.

34. CAUSES OF MINE FIRE FIRE CAUSED BY SPONTANEOUS COMBUSTION Premature collapse of pillars followed by spontaneous heating Collapse of pillars in active workings. Crushing of pillars in old workings. Spontaneous heating in goaved out panel. Spontaneous heating in active depillaring panel. Spontaneous heating in coal pillars of Development workings. Spontaneous heating on the surface.

35. CAUSES OF MINE FIRE FIRE CAUSED BY ACCIDENTAL OR OPEN FIRES In underground Illicit distillation of liquor Electricity Mechanical friction Blasting Locomotives Welding Explosions Sabotage

36. CAUSES OF MINE FIRE On surface Dumping of hot materials Lighting of fire near exposure of coal Burning of weeds near exposure of coal Illicit distillation of liquor in abandoned quarries

37. Preventive Measures of Fire a) Spontaneous Heating: proper winning of coal, not leaving carbonaceous matter, roof control, adequate ventilation. b) Electricity: Proper installation, regular inspection, good maintenance, provision of safe guards minimize electrical Fires. c) Friction: Lubrication of rollers, good maintenance. Using fire resistant material, Installing automatic fire sensor system, installing safety devices, maintaining correct alignment, keeping idler rollers will also reduce these fires .

38. Preventive Measures of Fire d) Staple pit fires : by using brake lining and rope treated with fire resistant materials, constructing fire proof engine rooms, fire protection by means of an automatic sprinkler system. e) Fires in Rope Haulage and Inclined Shafts : proper selection, installation and maintenance of rollers, pulleys and axle bearings may prevent fires. f) Miscellaneous: welding, cutting soldering, be performed by competent people, under the supervision of qualified persons at places free from danger due to fire damp or coal dust.

39. f) Miscellaneous : Adequate fires extinguishing appliances and using of stone dust reduce fires. g) Friction of belts and the dangers can be minimized by installing all machinery so as to secure a safe discharge of static electricity. h) Diesel powered equipment shall be maintained properly, malfunctioning shall be repaired immediately.

40. Explosion Proof Stoppings The percentage of CH4 in a sealed off area, shows 2% or more CH4, the isolation stoppings around the area should be strengthened suitably to make them explosion proof . An explosion proof stopping should consist of a pair of two brick stoppings built in cement mortar having minimum thickness of 1 m and spaced at least 4.5 m apart . The intervening space between the two stoppings should be packed solid with incombustible materials .

41. Locking of Isolation Stoppings The isolation stoppings should be well keyed into the roof, floor and sides, and for this purpose, the minimum depth of locking should be as follows: ( i ) In coal 1.0 m (ii) In sand stone roof/floor, 15 cms (iii) In shale stone roof/floor, 30 cms

42. Permanent Stoppings The thickness of the permanent stopping is nearly 1 m near the roof and it increases by 15 cm for every 3 m of height . In some mines like Jealgora stoppings had toe constructed in roadways 7 m high and in such roadways bottom 3 m section would be 1.30 m thick, the next 3 m section 1.15 m thick and the rest 1 m near the roof. The offset, if any, should be on the fire side so that the outbye side presents smooth surface which can be plastered and whitewashed for easy detection of cracks.

43. Fittings on Permanent Fire Stoppings A fire stopping should have the following fittings: 1) Water gauge, 2) Thermometer, 3) A sampling pipe, 18 mm dia , with a valve for collecting samples. The sampling pipe should pass through the temporary stopping and should extend about 3 m beyond it towards the fire side.

44. 4) 50 mm dia. Mild Steel pipe with plug for recording temperature of the atmosphere behind the stopping. 5) Water seal at the floor level for drainage of water. 6) A number plate giving the reference number of the stopping. 7) A signature board for signature and date after inspection. If the stopping is high such board should be at the top and ladderways or platforms should be arranged zigzag.

45. Sampling Pipe, Water Seal Location

46. Fittings on Permanent Fire Stoppings Sampling pipe should not be near the floor, nor near the roof but at a height between ½ and ¾ th the stopping height . Widthwise, it should be at mid width of the stopping. It should extend at least 3 m inside the stopping and to prevent its bending, should be supported on a brick pillar or a wooden prop. Stoppings should always be kept whitewashed.

47. Sample Collection Intervals Samples from behind the stoppings should be collected at the following intervals: i ) 48 hours after sealing … 8-hrs interval . ii) O2 falls to 10% or low and CH4 rises to 16% or more … 24-hrs, interval. iii) O2 falls to 5% or less and CH4 rises to 30% or more… 48 hrs interval or longer. Air samples from behind the stoppings should be drawn between the hours 12 noon and 2 p.m. (DGMS Cir. 15 of1961)

48. 134. General precautions against fire (1) No oil, grease, canvas or other inflammable material shall be stored in any mine except in a fire-proof receptacle. (2) Greasy or oily waste in workings belowground shall be regularly removed to the surface. (3) In case of opencast workings or workshops, greasy and oily wastes shall be disposed off regularly in a safe manner.

49. (4) No person shall place or throw, or cause or permit to be placed or thrown, any naked light or lamp on or near any timber, wooden structure or other combustible material. (5) Adequate and sufficient arrangements shall be made in every mine for early detection, control and extinguishing any fire. (6) Appropriate measures and precautions shall be taken to prevent, detect and combat the start and spread of mine fires.

50. (7) The owner, agent and manager of every mine shall ensure that operations are stopped and workers are evacuated to a safe location , when there is serious danger due to fire, threatening the safety and health of workers.

51. 135. Surface precautions against fire (1) All surface structures and supports within a horizontal distance of 10 meters from all entrances to a mine shall be of fireproof material with exemption as per DGMS. (2) Shale or other carbonaceous material not to be heaped or dumped, and dead leaves or dry vegetation not to be allowed to accumulate or remain, and combustible materials and inflammable materials not to be stored within a distance of 15 meters from any entrance to a mine.

52. (3) In opencast working and in any ground broken by extraction of coal, all wild or herbaceous plants shall be removed and all dead leaves and dry vegetation cleared as often as may be necessary, to prevent an outbreak of fire. (4) No person shall deposit any heated material or ashes on any outcrop of coal seam or in any opencast working or on any ground broken by extraction of coal.

53. (5) No person shall light a fire or permit a fire to be lighted in any opencast working or within a distance of 15 meters from any entrance to a mine . Provided that this sub-regulation shall not apply to boilers other than vertical boilers. (6) Inspection once at least in every seven days , of the top of all entrances to a mine, all opencast workings and any ground broken by extraction of coal. (7) A record of every inspection made and duly signed and dated by the person making the inspection.

54. 136. Underground precautions against fire (1) No timber or other combustible material to be used in the construction of any shaft lining or room housing of any machinery or apparatus belowground. (2) Wood cuttings shall not be left in any working belowground, but shall be removed to the surface at the end of every shift. (3) No person shall light a fire or permit a fire to be lighted in any workings belowground with exemption from DGMS

55. 3(a) in the case of a gassy seam of the first or second degree , flame or electric welding or repairing apparatus may be used belowground if permitted by an order in writing of the manager and every such order shall specify the person who shall be in-charge of the apparatus; and 3(b) in the case of a gassy seam of third degree , a flame or electric welding or repairing apparatus may be used belowground if prior permission in writing has been obtained from the Regional Inspector and subject to such conditions as he may specify therein.

56. (4) No person shall leave a portable light or lamp belowground unless he has placed it in-charge of some other person remaining therein. (5) At the end of a shift, unless the mine is worked by a continuous succession of shifts, after all persons have left the mine, all lights shall be extinguished and all power cut off.

57. (6) Provision shall be made to prevent an outbreak of fire belowground or the spread of fire from any part of the mine or from any adjoining mine, and adequate steps shall be taken to control or isolate any such fire or heating that may occur. (7) All unused open workings connected to the surface, shall once at least in every thirty days be inspected by a competent person for signs of illicit distillation of liquor and a proper report of every such inspection shall be recorded and maintained.

58. 137. Precaution against spontaneous heating (1) The seam or section shall be worked in panels having independent ventilation in such a manner that it is possible to isolate one from another easily when necessary. (2) Where the seam or section has already been developed without complying with the provisions of sub-regulation (1), artificial panels shall be created by construction of stoppings .

59. (3) Panel size to enable complete extraction of the pillars therein, within the incubation period of the coal seam. (4) No coal, shale or other carbonaceous material shall be left or stacked belowground. (5) Where removal of fallen coal out of the mine is not practicable, the area shall be effectively sealed off.

60. (6) Except otherwise permitted by the Chief Inspector in writing and subject to such conditions, no extraction of pillars in any seam or section shall be commenced until fire dams or stoppings have been provided in all entrance to the panel. (7) In the fire dams or stoppings built in entrances which are to be kept open for ventilation or haulage, suitable doors or openings may be left and bricks and other suitable materials shall be kept readily available in the vicinity .

61. (8) Shale or other carbonaceous material shall not be used in the construction of fire dams or stoppings. (9) A panel shall be isolated by adequate stoppings as soon as it has been goaved out. (10) All the isolation stoppings erected to seal off the goaves or to isolate old, abandoned or disused workings or to isolate area affected by fire or spontaneous heating shall be plastered with cement and white washed.

62. (11) Sufficient material for dealing with fire kept ready at suitable places belowground and a sufficient number of persons trained in the use of such material. (12) To detect spontaneous heating in early stages, the air in the return airway and of every goaf , shall be - (a) tested for percentage of carbon monoxide once at least in every seven days with an automatic detector. (b) completely analysed once at least in every thirty days to determine the ratio CO formed/ O2- absorbed:

63. (13) The result of every test referred to in sub-regulation (12) shall be recorded in a bound paged book kept for the purpose and shall be signed and dated by the person carrying out the test. (14) Every depillaring district shall be inspected on every idle day and a report of every such inspection shall be recorded in a bound paged book kept for the purpose, and shall be signed and dated by the person making the inspection.

64. (15) All unused workings not been sealed off, and isolation stoppings built around goaved out areas shall be inspected once at least in every seven days, by a competent person for any fire risk and a report of every such inspection shall be maintained in prescribed manner. (16) Where at any mine or part, special conditions exist which make compliance with any of the provisions of this regulation not necessary or reasonably practicable, the Regional Inspector may grant exemption.

65. (17) Where coal is stacked on surface, suitable arrangement shall be made for spraying of water or any other fire resistant or suppressant materials on the coal stack at regular intervals so as to prevent spontaneous heating. (18) Hydraulic fluid which is not fire resistant shall not be used belowground. (19) Precautions shall be taken to minimise the possibility of hydraulic fluids or oils coming in contact with hot surface, electrical apparatus or cables.

66. (20) Combustible oils or material shall not be used for filling in electrical equipment . (21) Notwithstanding anything contained in the sub-regulations (18), (19) and (20), the Regional Inspector may by an order in writing, exempt from use of fire resistant hydraulic fluid in degree-I gassy mine subject to such conditions as he may specify therein.

67. 138. Precautions after a fire has broken out (1) On the appearance of smoke or other signs indicating that a fire or spontaneous heating has or may have broken out, effective steps shall be taken, to deal with the fire or heating and all persons other than required for dealing the fire, shall be immediately withdrawn from the mine. (2) No person, other than those required for dealing with or sealing off the fire or heating, shall be admitted in the mine until the fire or heating has been extinguished or effectively sealed off and declared safe.

68. (3) The examination shall be made with an approved flame safety lamp and other means of detecting carbon monoxide gas approved by the Chief Inspector. (4) During the whole time that any work of dealing with or sealing off a fire or heating is in progress – (a) a competent person shall be present on the spot throughout;

69. (b) adequate precautions shall be taken to prevent danger to persons from any noxious, asphyxiating or inflammable gases, flame, steam and ejected or rolling down hot material, explosion of water gas, and falling into crevices or pot holes, that may occur in the area on fire;

70. (c) there shall be kept available, at or near all places belowground: ( i ) adequate number of self-rescuers and at least two smoke helmets or other suitable apparatus, approved by the Chief Inspector, for use in emergency; (ii) an apparatus for detecting carbon monoxide gas approved by the Chief Inspector; and (iii) a flame safety lamp or other means of detecting carbon dioxide gas and oxygen deficiency, approved by the Chief Inspector.

71. (5) The manager shall make a detailed scheme for- (a) the provision and maintenance of suitable fire-fighting arrangements; (b) the prevention, detection, dealing and control of any heating or fire; (c) the examination and maintenance of the protective measures taken to control or isolate a fire or heating; (d) ensuring safety of persons engaged in the said operations, and the scheme shall be suitably modified and kept updated as the situation warrants.

72. METHODS OF DEALING WITH FIRES In the light of the matter already discussed, particularly the possible degree of pollution the real need for the wearing of self contained breathing apparatus under the conditions which obtain on the occasion of an underground fire should always be borne in mind. It is, in fact, extremely difficult to imagine conditions on the return side of a fire being such that it would not be essential to wear breathing apparatus for all work entailed on that side.

73. Broadly classified, there are two types of underground fires, those which - (a) involve exposed surfaces and are known as open, freely burning fires; and (b) those which may be wholly or partly concealed, and are invariably caused by spontaneous beating of coal itself, known as “gob fires” Once discovered, the treatment of heating or fires varies with the conditions. When a fire is readily accessible to the fire fighting personnel, extinction of it may be achieved by smothering it out by building airtight packs all round the seat of the heating.

74. In some cases fires are dug out, but this is only possible when they occur near a roadside. Digging out, but is an operation involving considerable risk and calling for knowledge, skill and experience, and should always be entrusted to specialists. At some mines where the seams are liable to spontaneous combustion such team of specialists, known as the “gob-fire squad”, is engaged continuously on the problems associated with heating.

75. It has been found inadvisable to use water for extinguishing gob fires except in circumstances when the whole affected area can be flooded and the fire submerged. Danger arises in other cases from the formation of water gas, which may form a dangerous inflammable mixture. In some cases fires have been put out by the injection of carbon dioxide through stoppings sealing off the affected area If a fire is readily accessible, extinction of it may be achieved by the direct application of some substance which will cool down the hot mass below it ignition temperature, or, in the case of oils, will arrest the volatilisation process by sealing or emulsifying the oil surface.

76. A fire occurring in a mine may be partially or completely inaccessible, in which case an important part of the operation would consist of obtaining access to it. When it is not possible to extinguish a fire by direct attack, it is necessary to seal off the district, or districts, on that split. To effect extinction this way, stoppings are erected at convenient places to cut off effectively the air supply, after which the combustion process uses up the available oxygen within the sealed area, the process is arrested and the hot ground cools gradually as the heat is conducted away by the surrounding cooler area. The choice of site and the building of the stoppings is highly special work calling for may precautionary measures and only to be entrusted to specialists.

77. Different Methods of Dealing with Fires and their Applicability: i ) Fighting by direct attack - applicable when fire is small and easily approachable. ii) Fighting by indirect attack - applicable when fire is large and not approachable. a) Isolation of the fire. b) Sealing the fire area or the entire mine. iii) Flooding the fire area or the entire mine – applicable when fire spread to entire mine

78. iv) Flushing the fire area with sand or other suitable solid materials conveyed with water - applicable to fire is small, easily accessible v) Introducing inert gas into the fire area - applicable to fire is wider extent, not approachable. vi) Special methods of fire fighting - applicable to special conditions.

79. EQUIPMENT USED IN DIRECT ATTACK a.Tools for timbering and digging out. These include shovels, picks, saws, axes, hammers and pinch bars. The advantages of having available skilled men to carry out work requiring the use of such tools need no emphasis. b.Fire extinguishers; soda-acid, carbon dioxide+water, carbon dioxide snow (for use on electrical equipment), chemical foam (for use on oil fires) c.Two-men manual pumps. d.Piped water supplies.

80. 139. Equipment for fire-fighting (1) In every mine,- (a) unless expressly exempted in writing by the Regional Inspector, adequate quantity of water at sufficient pressure shall be provided to all working places belowground and all other places of fire risk such as coal stocks, spoil heaps containing carbonaceous material and exposed coal surfaces liable to heating, for the purpose of efficient fire fighting;

81. (b) fire stations with suitable supply of fire-fighting equipment to be established on surface / underground; (c) sufficient supply of sand or incombustible material and suitable portable fire extinguishers in sufficient quantity or automatically operated fire suppression devices shall be provided at- ( i ) every entrance to a mine or district and at every landing and shaft bottom in use; (ii) every place where timber, grease, oil or other inflammable material is stored;

82. (iii) every engine room, diesel engine maintenance workshop, filling station and storage battery charging station; (iv) on every track-mounted and trackless locomotive, self propelled man riding car and personnel carrier; (v) each permanent and temporary electrical installation; (vi) at locations where welding, cutting or soldering with arc or flame is being done; (vii) every machinery, plant and installations; and (viii) such other special places of fire risk as may be specified by the manager;

83. (d) every heavy earth moving machinery used in opencast workings shall be provided with automatically operated fire detection and suppression device or system: Provided that in case of trucks and dumpers of less than 35 tonne capacity, it may be sufficient if semi-automatic type fire suppression system has been provided; (e) specially designed water foam spray, deluge systems or dry chemicals shall be installed above each belt drive, belt take up, electrical control, gear reducing unit and other strategic locations on the conveyor belt system;

84. (f) adequate number of suitable fire extinguishers or automatically operated fire suppression devices shall be provided on continuous mining machines, other face cutting machines, loading machines, roof bolting machines and other hauling machines. (2) Soda-acid type extinguishers or water shall not be used for fighting oil or electrical fires. (3) Foam type extinguishers shall not be used for fighting electrical fires.

85. (4) Fire-extinguishers containing chemicals which are liable when operated, to give off poisonous or noxious gases shall not be provided or used belowground: (5) All types of fire fighting and fire suppression systems including automatic fire detection and suppression systems to be used in machinery and plant including heavy earth moving machineries, materials and chemicals to be used in fire sealing, fighting or suppression systems in mines both on surface as well as belowground shall be of such type, standard and make, as approved by the Chief Inspector by a general or special order.

86. (6) A competent person shall, once at least in every month, examine all the equipment, material and arrangements provided for fire-fighting to ensure that these are in proper working order and any deficiency found during any such examination or otherwise shall be immediately remedied. (7) A report of every examination made under sub-regulation (6) shall be made in a bound-paged book kept for the purpose, duly signed and dated by the person making the examination.

87. 140. Organisation for fire fighting (1) Proper organisation for fire fighting in the mine. Installation of fire stations at surface and at suitable places in ug with adequate fire fighting equipment kept in every such fire station. (2) Sufficient number of plans prepared showing the fire fighting equipment including the water mains, taps, fire-stations, pumping stations, ventilation system and escape route along with such other information as may be useful for the purpose of fighting fires. Up-to-date copies of these plans shall be kept available.

88. (3) Adequate number of persons, including all operators of plants, machinery and heavy earth moving machineries, shall be trained in the use of fire-extinguishers and in fire fighting and such persons shall be made familiar with the position of all fire fighting equipment. (4) Standing Orders containing the procedures that may be adopted in giving warnings of fire, timely withdrawal of personnel from the mine and for the conduct of fire fighting operation to be maintained.

89. 142. Precautions when a fire exists (Inspection of Stoppings) (1) No person shall be employed in any seam,– (a) where a fire or spontaneous heating exists in a lower seam whether such fire has been sealed off by means of fire stoppings or not; or (b) where the seam has a common ventilation system with another seam on fire; or (c) where the outlets or openings of the seam are within 60 meters of an active fire or spontaneous heating in a higher seam or on the surface in any ash heap or spoil heap or in any other heap or place or any other fire or spontaneous heating which cannot be controlled immediately or where broken ground connected with the seam exists within 60 meters of such fire or spontaneous heating; or

90. (d) where the parting, with an overlying seam on fire or in which spontaneous heating has taken place, or with surface containing an active fire or spontaneous heating in any spoil heap or ash heap or in any other heap or place, or with any other fire or spontaneous heating which cannot be controlled immediately, consist of less than 10 meters of hard rock, except with the previous permission in writing of the Chief Inspector and subject to such conditions as he may specify therein.

91. (3) In every coal seam, arrangements shall be made once at least every thirty days to ascertain the atmospheric condition behind the stoppings built to seal off the area of old workings, or such goaf , or a fire or spontaneous heating, unless such stoppings are capable of resisting force of an explosion. (4) Every stopping erected to isolate or control a fire or spontaneous heating shall be numbered, and shall be of adequate strength and so maintained as to prevent any leakage of air or gas through it.

92. (5) Every stopping erected in accordance with the provision of sub-regulation (4) and the pillars containing such stoppings, shall be plastered with fire resistant or fire retardant sealant of adequate thickness using high pressure guns so as to completely fill up the cracks, cavities, crevices, joints, slips, fractures and cleats present in the working in order to completely seal off such area, which shall be kept maintained as leak proof.

93. (6) Where in any mine or part thereof the provisions of sub-regulations (4) or (5) have not been complied with or where in the opinion of the Regional Inspector the steps so taken are inadequate, he may give notice in writing to the owner, agent or manager requiring him to take such protective measures, within such time, as he may specify therein: Provided that in case of non-compliance with the requirements of the notice under this sub regulation, the Regional Inspector may, by an order in writing, prohibit until the requirements of the notice have been complied with to his satisfaction, the employment in the mine or part, of any person whose employment is not, in his opinion, necessary for the purpose of complying with the requirements aforesaid.

94. (7) A competent person shall, once at least in every seven days, inspect all stoppings erected for isolation or control of fire or spontaneous heating belowground to ascertain the general condition of every stopping by checking it for leakage and presence of gas, and the temperature and humidity of the atmosphere outside the stopping.

95. (8) The competent person shall after carrying out the inspection under sub-regulation (7), place his signature, with date, on a check-board provided for the purpose at a suitable position on the stopping, which shall be maintained for a period of not less than three months, and a report of every such inspection shall also be recorded in a bound paged book kept for the purpose duly signed and dated by the person making the inspection:

96. Fire Classification All fires are grouped into classes, according to the type of materials that are burning. Class A: Fires are those involving free burning materials, such as paper wood, fabrics and other textiles, and also plastics Class B: Fires involve flammable liquids and solids, such as diesel, petrol and oils (but not cooking oils), plus solid fuels such as wax Class C: Fires involve flammable gases, such as propane, butane and methane Class D: Fires involve flammable metals such as sodium, potassium and magnesium Class E: Electrical equipment fires involve electrical equipment such as switchgear or computers. (These are sometimes referred to as Class E fires, although the category does not officially exist in the UK*) Class F: Fires are specific to cooking oils and fats

97. Extinguisher Types Carbon Dioxide (CO2) Fire Extinguishers: Suitable for fires involving flammable liquids or electrical apparatus. Foam (AFFF) Fire Extinguishers: Suitable for most fires involving flammable liquids, apart from cooking oil fires. Dry Powder Fire Extinguishers: Suitable for most fires involving flammable liquids or electrical apparatus. Water Fire Extinguishers: Suitable for most fires except those involving flammable liquids or live electrical apparatus.

98. THANK YOU....