COLLIERY FIRES.

Otago Daily Times, Issue 13651, 21 July 1906, Page 4

COLLIERY FIRES.

In Hie working of a coal mine a matter of the most vital importance is the maintenance of an air current sufficient in quantity lo sweep out the noxious and inflammable gases—exuded froln the coal or produced by the breathing of the miners or by the action of their, explosives, etc.—nnd lo replace these with pure.air from .outside. This air may enter by a shaft (called the " downcast' 1 ) or a tunnel (the " intake"), It is caused to divide into several portions which are Jed to the different working faces, finally uniting at tho bottom of the "up-cast" or at the extremity of the "return airway," through 'wln'clr they pass to the outer air. This movement of the air is usually brought, about by a, fan which exhausts the return air-wuy; the pressure of tho air outside then sets up a current through the intake and round the faces as described. Short-cuts through worked out galleries are prevented hy barriers of waste material, canvas screens on wooden frames or doors, The air in the return is, of course, very foul, so that it is to be expected thai the miner on his way to his work will choose the longer but more pleasant route through the. intake. The usual practice is to work " advancing," the roads being driven from the downcast outwards, coal being won as they-are extended. hires iu coil seams most frequently originate in the " go!>"—the line coal waste left behind in the workings. The miner is then surprised bv the lire "in bye"—i.e., ho is on the return side of it —Mid-in order lo reach flic open air he has to flnel his way along an unaccustomed road in a choking and irritating, perhaps poisonous, atmosphere. If the firs is of any considerable, magnitude, presently lie will begin to feel a drowsiness creeping over him, there is a ringing in his ears, perhap.i a pain across the. temples, lie knows thai, these are the symptoms of thy action of "blackdamp" from the burning co,;!, and he struggles against the dreadful lethargy Attacking him. " Hlnckdamp" is heavier than air, and at each respiration he retains a certain ' amount in hi: lungs. Soon his breathing quickens, lift begins to pant, the drowsiness ificreases. and he presently succumbs and. fn|| s unconscious. The purer air which—being colder I —hugs tho floor may revive him, and ho scrambles along on all-fours, finding his way as best he can. (lis lamp lias probably been extinguished in the [all, and in most pits he would not carry matches. Small wonder, then, if he loses his bearings, and, perhaps, hi-i life. If, on the ■ other hand, he rem::ins quiescent in his "working place," hii chance is little better. A fire soon burns out the sloppings erected lo guide the air, and the current will be certn|"iy changed, perhaps even locally reversed. Then the ('nine aiid noxious gases will catch him penned up there like a rat in n trap. In i7iy case it can hardly be long before t';e air surrounding him is vitiated. The averago miner, however, on discovering by a sensation of unusual heat or the smell of smoke Unit (ire has broken out in his vicinity, neither incontinently runs away nhij sits in n corner awaiting deallj or rescue, whichever Kate may have in store. Ilis first thought is to isolate the fire by building a wall round it. ITe may have little difficulty in thus nipping; in the bud what might if unchecked menace the life of every man in the mine. If the firo is allowed to spread towards jjnssy or dusty workings, an explosion or, at tho least, a nifiji of flame inuy occur. So with his mate's ho sets to work, and in innumerable cases has. succeeded ill damming off the fire thus early in its history, Ifow intense the heat generated by such a rush of flame may bo can bo judged from n description by Mr John Hayes (Government Inspecting I'lnginoer of Mines), of the I'rnnner Mine, after the disaster in 1896 :—" Tho place hod literally glowed like u furnace; the volatile matter being distilled out of the roof coal, from winch were hanging, like black stalactites., droppers of brittle carbon up lo four inches in length." The fiery w^ave-leaves behind it-charred and yielding timbers and u most deadly atmosphere, so that the u'iner' who, ensconced in some side gallery, lias for the time escaped may be crushed by falling earth or poisoned by noxious gases.

Seen from the surface, a fire first declares itself by tv ilonse smoke, possibly accompanied by flames or by an explosion. Miners and their friends gather from all directions, and, if the pit is nn exlensivn one, tho roll is called, and the number of men imprisoned is thus ascertained. The plans of the workings, which at a colliery are kept right up to date, are consulted, and the best scheme for effecting a rescue is decided upon. It is at moments like this that the vnliio of experience in the management is fully realised. Only a man with a thorough grasp of underground work can predict with any approach to accuracy what changes have been made in the air-current and how best the entombed men may be reached. Tho rosciiors enter the pit in (lie manner decided upon,—usually at the return. 'The bodies they encounter are examined, restoratives are applied if possible, and the sufferers aro sent to bank. Often compressed oxygen is carried in bottles. A man rendered unconscfous by

" blackdiimp" is not a pretty sight. Ilis lips are a livid blue, his features swollen ilnd contorted, bis hands clenched, he appears to have made a hard fight of it. Yet he has far more chance of life than the man who has fallen under the influence of "white-dump." This deadly gas is produced by the incomplete combustion of coal, and is contained in blackdamp usually, invariably in the "afterdamp" remaining after an explosion. Its presence cannot be detected by ordinary means—a candle, for example, will burn with ' more than usual brilliancy in an atmosphere containing a deadly percentage of this gas. The fallacy of the popular idea' that where a candle will buiii it is safe for a mall to go is well exemplified iu the account given to the writer by nut. of the rescue party at a fatality that occurred a few years ago :' "We got down to the chamber and looked along tile drive. Two bodies were lying stretched out on the floor a little more than a chain away. Their candles were burning brightly enough, so in we went-. In single file, of course; 1 was the third man.' Suddenly the leader went down. The second man beiit down to pick bun up, nnd he went out ton. I stooped to help him, and the next thing I remember was coming-to on top." A mail may be badly poisoned by this gas, oven dead, but bis lips mid cheeks will wear the hue of perfect health, his face will show no signs of distress or past agony, be will appear to be sleeping peacefully. The work of rescue is greatly facilitated by the provision of respiration jackets (elementary "diving dresses") and little low two-wheeled trucks. Thus armed the rescuer can enter almost any atmosphere, roll his comrade on to tho truck, strap .him securely, and rapidly drag "him to a place of safety. These jackets—of tho Vajenbader type-are provided at some New Zealand mines (Nightcaps, Kaitangata, Westport, etc.), but, so far as the writer knows, the truck has not been adopted in the colony. When all have been brought out alive or dead; or, at the least, after weeks of fruitless seach for those still .remaining below, the mine is flooded or hermetically sealed. In the latter case it is expected that the deprivation of air will extinguish-the fire, but sometimes some such gas as carbonic acid is introduced lo hasten this. Then when the nit is opened, thoroughly inspected, and declared free from fire, work is resumed. Thero is usually no lack of applications for employment. The very men who have recently passed through such a grim 07deal show no reluctance in returning to the pit. It would seem that they think a fire* is "all in the day's work.* and that every precaution is exercised that science can suggest. There is this much lo be said for their view: that more than half the fatalities that occur in collieries, taking one year with another, are due to causes other than underground fires and explosions.