FATALITIES IN COAL-MINES

Otago Daily Times, Issue 13946, 4 July 1907, Page 5

FATALITIES IN COAL-MINES

THE NIGHTCAPS DISASTER.

The present article aims at presenting tho technical questions relating to the recent and similar ,deplorable occurrences before tho average reader clearly, with accuracy, and without dragging in chemical formula.

'Ehcro are two oxides of carbon— viz, (1) tho higher or di-oxido (carbonic acid) and (2) the lower or mon-oxide (white damp). When carbon—.whether in coal, minetimber, or any othel- form—is burnt in sufficiency or excess of oxygen the former (C! 02) is produced, but when the carbon is in oxoass the l&fer (CO). CO is a deadly poison, CO2 has little, if any, toxio aotion. If a current of CO2 impinges on red-hot carbon it is reduced to CO, and more CO is formed. If CO mixed with air is exposed to the action of flame then CQ2 is formed. Any claim that an increased ventilating current during a colliery firo would result in an increased evolution of 00 can thus hardly be substantiated.

If a man were to sit down for Jialf an hour in ail atmosphere slightly polluted, say to 'the oxtent or 1 in 1000 by CO ho might feel nothing until he rose and began to movo about. Such conditions do not usually obtain in coal mines, either during ordinary working or in the event of a fire, and generally it may l)o said'that symptoms become well marked long beforo they aro ul'gcnt, and are at all events easily recognisable by a man with knowledge. To 6omo this knowledge may, come through experience, to some by instruction. As regards the latter, the miner in the southern district is not too favourably situated. The only mining institution in this part of the country is that attached to the Otago University, but-it does not cater for the working miner, who, to attend its courses, would need io givo up his employment. ' The next point that arises is how the presence of the deadly gas can be detected. Puro CO has no smell, hut |\vhito-damp as usually found in collieries oontain6 certain volatile hydro-carbons ,which communicate to it a peculiar faint and sicldy odour whoso strength -varies. " Safety" lamps havo been mentioned in this connection. Now, there aro almost innumerable patterns in use in coal mines for actual working; but these are so little suited for testing purposes that before anything of importance could be proved by them their holder would have lost interest in the subject. It is, however, true that special types of detectors might be" employed which would givo results with small quantities of whitedamp, and which would be classed by the public—and many miners for that matter— as " safety " lamps. The use of a dissolving medium such as cuprous chloride and other methods, while chemically correct, are out of the question considered practically. The only artifice of any valuo is the exposuro of a small living animal—such 1 ns a mouse— to the actioD of the suspected atmosphere, the rule being that when the mouse staggered the man should, retire. " Now it is -provided by law that at certain times the management must withdraw the men from the mine, and it may seem strange, if the symptoms aro as marked as stated above, that such a rule should, bo necessary. A.. Wynter Blyth . says: "In non-fatal but 'moderately 6evero . cases . . . . a weakness of the understanding, incapacity for rational thought, aijd even insanity have been noted." This is not incompatible with the sufferers finally fatting - asleep with a placid expression on their faces, although it certainly explains why novices do not escape at'the first warning. On the other hand, the experienced miner is usually busily engaged, and trusts to his mates at bank to keep him supplied with sufficient air to prevent an increase in the proportion of poison. He keeps, of course, on the "intake" side of the fire, and so long as the current is not stopped or reversed ho is safe. A general reversal cannot occur, in the absence of explosion, unless the fan is ridicuously small, but a local reversal may be brought about by "stoppings" being burnt through.. The possibility ol this again depends upon the inflammability of the materials used for said stoppings.

But assuming that the formation, of CO cannot be prevented, and that entombed miners will be struck down by tlie poison, is it possible to minimise the danger which the rescuers must facc? There are -various eiDoJte helmets and other devices on the market designed to permit miners to walk unharmed in the' most poisonous atmosphere. Unfortunately most' of them also restrict his movements. A " Flcuss Apparatus," said to bo without this fault, was shown by the Mines Department at the rceent Exhibition, but its present whereabouts is unknown to the writer. One suitable place would be the Otago Mining School, where students could learn its use and demonstrate its practical value, and whence it could be sent to any point in the southern district whore the need existed. Mention was made at the inquest of attempts'being madn to place an unconscious man upon a coalbox to facilitate his removal. A simple two-wheeled truck with a handle and suitable straps might bo provided at each mine at the cost of a few shillings. Again, when the sufferers have been brought to bank what can be done for them? Apart from disturbance of the nervo centres .their trouble i 6 that much of their blood has been rendered temporarily useless. Briefly, it mav be explained thus: There is a purple substanco in the blood termed hcemoglobin (Hb) and a liquid, the plasma, with, of course, other constituents. This lib is capable of entering into unstable composition with _ oxygen, forming Hbo2.' which gives arterial blood its wellknown red hue. The oxygenated blood readily parts with tho oxygen to the absorbent tissues with which it comes in contact. But Hb has a much stronger affinity for CO (Wabncr says 450 times as strong), and tho product can only bo broken up by the slow processes of nature in the living animal. (HbCO has been found in a corpse exhumed 18 months after doat.ii.) When the blood ■is sufficiently saturated with HbCO death must supervene, unless somo other • means •is employed for giving the necessary oxygen to tho tissues. This means is found in the plasma, which will dissolve the oxygen and carry it round the circulatory system Hundreds of lives have been saved at colliery disasters by tho inhalation of compressed oxygen. Such can be procured in iron bottles from any dealer in limelight apparatus. It is not expensive, and does not deteriorate rapidly. It is not provided at. New Zealand mines because no rules have been issued by the Minister on the subjcct. But it has been abundantly proved by the experiences at Courrieres last, year—quite apart from the writings of lialdane and others—that compressed oxygen is a most valuable specific. Looking at the matter from another point of view, ono reads that a man was brought up unconscious from tho Nightcaps mino and only recovered consciousness, _ after two hours perseverance with artificial respiration. Oxygen would have revived him instantly. Tho gist of the foregoing would seem to be that: ' (1) Bottles of compressed oxygen should be kept at all coal mines, whether'fiery or not: (2) Efforts should be made to reach miners in parts remote from mining schools by lectures from men who understand the subject.; (3) Stoppings should invariably be built in gassy mines or non-gassy mines in wliioh a fire iu burning of non-inflammable materials. MINE GASESi AND VENTILATION. Iji view of the recent deplorable accidentat Nightcaps coal mine whereby three men lost their lives, the following excerpt front Professor Park's annual report on the Qtago School of Mines dealing with the ventilation of. mines ana the determination of mine gases will be read with interest by thosn eneaeed in coal-mining:—

" The great development of underground mining in recent years and the increasing depth of mines liavo added much to the difficulty of providing a ventilating current that shall swfiCß away all nosiflus gase;?

and give a constant and sufficeint supply of pure air. The maximum effort of a workman is obtained between temperatures ranging from 55dcg to 75dcg I'ahr., and in proso'nee of a sufficient supply of pure air. Henoe, apart from its purely humanitarian aspect, the preservation of the health of tho workman is now rccognis'cd as an important brancli of mining economics. "Mines vary in extent, and depth, in the character of the' mineral being mined, in tho gases given off, and in tho number of men employed.. Whore tho conditions vary so much no hard and fast rule can be laid down as to what shall constitute sufficient pure air tor any particular mine or group of mines. Every mine is a law unto itself.

" In the coal mines of Europe and in th(j deep gold mines of the Transvaal tho constitution of the mine gases has become the subject of closo scientific investigation. It has been found that no rule of thumb methods, no amount of practical experience in mining, can tell when the mine air is pure and wholesome or when it is vitiated to a dangerous extent. Only exact chemical analysis can do so.

"Tho causes and prevention of minors' diseases have also been matters of closo investigation, with results that have already done much good by directing attention to improved methods of underground sanitation."

There are many other points which might bo touchcd upon, but pressure on space forbids. .