APPENDIX I.

REPORT OF THE ROYAL COMMISSION ON ACCIDENTS IN MINES.

66

In concluding their Final Report (dated 15th March, 1886), the Royal Commissioners appointed to inquire into Accidents in Mines gave a Summary' of the most important subjects which had been dealt with in their several Reports, and of the chief conclusions and recommendations which they had adopted.

The Commissioners were Sir Warington W. Smyth (Chairman); the Earl of Crawford and Balcarres; Sir George Elliot, Bart., M.P.; Sir Frederick Abel, F.R.S.; Professor Tyndall, F.R.S.; Mr. Thomas Burt, M.P.; Professor R. B. Clifton; Sir W. T. Lewis; and Mr. Lindsay Wood, M.P.

The Commissioners' "Summary" is as follows:

Ventilation.

Volumes of air sufficient for the ventilation of even the most extensive collieries are capable of being passed through the workings by means of properly constructed furnaces, or by mechanical contrivances, such as are already in action at most of the collieries.

At a large number of collieries the sectional area of the intake and return-aircourses may be increased with advantage.

Where furnaces are used, they should by preference be in connexion with dry and deep shafts, and should be provided with dumb drifts.

Where mechanical contrivances are employed, they should be in such positions and placed under such conditions as will tend to insure their being uninjured by an explosion, and, if they are not provided altogether in duplicate, there should be at least an engine in reserve.

The improved system of ventilation by "splits" and the shortening of the aircourses, as practised in the larger collieries, is a subject of great importance, and we recommend that more general attention should be given to it.

It would conduce greatly to safety if the system of carrying the intake air through two parallel drifts, of which one may be used as the travelling road, were introduced into workings likely to become extensive, and where mechanical haulage is intended to be employed.

Fall of Roof and Sides.

That the casualties due to falls of the roof and sides are much more numerous than those due to any other causes is demonstrated by the tabular statement given at the commencement of this report. It is essential that all the officials and workmen in mines should pay special attention to the careful propping of the working places and travelling roads.

In the North of England the system of trusting mainly to officials (deputies) for the timbering, is found to answer well; in South Wales and other districts,

where the roof, face and sides are more liable to falls, the system of the men timbering their own working places has been found to be best.

We are of opinion, however, that in all cases the security of the working places should be examined into by over-lookers once at least in the course of each shift.

Supervision has been greatly enlarged in the last 35 years, and we find that there is generally one official so employed to about 20 men, sometimes one even

to II or 12 men.

In order to reduce the number of casualties from falls, we recommend the observance of the following:

A. The maintenance of ample supplies of timber in localities convenient to the workmen.

B. The proper training of each miner to the best modes of timbering and of otherwise protecting his working place.

C. The exercise of increased care on the part of the workmen in watching the roof, sides and face, and protecting themselves in time.

D. The introduction, as far as possible, of arrangements with the workmen, which will make it their interest not to avoid the labour of putting up

the necessary timber, cog walls, buildings, or cogs for their proper protection.

E. The employment of special timbermen or deputies for the timbering of main-ways and also for the repairing as well as drawing of timber.

F. Preventing timber being left in the goaf of longwall workings, which would have the effect of breaking the roof.

G. Driving the working places as rapidly as possible by shifts of an ample number of workmen in each face, and so reducing the risk of falls and exposing the least number of men to danger at any one time.

Miscellaneous Accidents.

We are of opinion that by improved discipline and the exercise of greater care by those employed in or travelling through engine planes and other roadways, the number of casualties comprised under the head of "miscellaneous accidents," would be considerably diminished. The practice in some collieries in South Wales of boys running in front of the horses and trams should be prohibited.

The very numerous casualties under the heads of "falls of roof and sides" and "miscellaneous accidents," are due in great part either to carelessness or want of early training. Looking to the importance of practical training and of encouraging boys to enter the mines at the ages specified by the Mines Regulation Act, we are of opinion that careful consideration should be given to this point in connexion with the administration of the Elementary Education Act.

Fire-damp.

We think that the experiments we have made on the pressure of fire-damp in plugged bore holes, in coal, a pressure sometimes amounting to upwards of 400 pounds on the square inch, have thrown much light upon the occurrence of sudden outbursts of gas. The boring of holes upward or downward has been successfully tried as a means of avoiding such outbursts, and we have little doubt that the closer attention which is now paid to thorough stowing and packing or building in the workings will contribute greatly to the same end.

It is almost impossible to account for many of the accidents which have occurred in well managed mines, some of which have originated in the mainintake airways, except upon the supposition that gas has suddenly invaded the workings from the adjacent strata. Sudden outbursts of large quantities of gas,

accompanied by violent disruption of the floor, roof, or coal, are fortunately rare, but smaller incursions of gas, accompanied by falls of roof, or even without any apparent displacement of ground, are comparatively frequent.

We are of opinion that in working fiery seams at great depths such abnormal discharges of gas must occasionally occur, yet that they may be successfully met by ample ventilation, good discipline and efficient lamps.

While we recognise that variations of atmospheric pressure exert an influence on the escape of gases which have accumulated in cavities, and possibly to a slight extent on that of gases emitted directly from the coal, we entertain great doubt as to the wisdom of placing reliance on the issue of meteorological warnings. These can at best only convey very imperfect information, which, moreover, may be sometimes dangerously misleading. We are of opinion that safety would be much more likely to be ensured by unceasing vigilance on the part of the officials and workmen in the mine than by any attention to such warnings.

Coal-Dust and its Relation to Explosions.

The action and effects of coal-dust in connexion with mine explosions have been made the subject of careful study and comprehensive experiment by numerous workers since attention was first drawn, about 42 years ago, by Faraday and Lyell, to the functions exercised by coal-dust in "aggravating and extending the injurious effects of fire-damp explosions." The results and conclusions which have been arrived at in this direction, and to which the labours of your Commissioners have contributed, are sufficiently complete and definite to warrant the following authoritative statements:

The disastrous effects of fire-damp explosions in coal-mines are almost always aggravated and extended by the existence of coal-dust in dry mine-workings and roadways.

A gas explosion in a dry mine, even if only of comparatively trifling nature, will raise and inflame coal-dust existing at the seat of the explosion or in the vicinity; the flame attending the explosion will be thereby increased and carried to more or less considerable distances, and may thus become communicated to any accumulations of explosive gas-mixture which may exist in goaves or other lurking-places at a distance from the seat of the original gas explosion.

The firing of an explosive in a shot-hole of a strength which is in excess of the power applied, or which has not been sufficiently tamped, will result in the almost complete projection of the highly heated products of explosion and of a more or less considerable body of flame from the mouth of the hole, as from the bore of a gun; it thus produces what is known as a blown-out shot. And further, if the charge of explosive is decidedly greater than that necessary to perform the desired work in the coal or stone where it is applied, a more or less considerable projection of highly heated products of explosion will also take place, and effects. similar to those of a blown-out shot will be produced.

The production of a blown-out powder-shot in a mine working, in the entire absence of coal-dust, or in a wet mine is not attended by the projection of flame to a very considerable distance, but the flame thus projected is much increased in volume if, as is frequently the practice, dry or slightly damp small coal has been used as stemming for the shot.

If a blown-out powder-shot be produced in a dry locality where coal-dust exists in more or less abundance, the flame, projected by the shot, is sure to be considerably increased and extended by the ignition of portions of the dust-cloud which is raised by the rush of air occasioned by the firing of the shot. A result of this nature will be produced even if the air in the vicinity of the blown-out shot is entirely free from fire-damp.

Unless the coal-dust which exists in the immediate vicinity of a blown-out

powder-shot is dry, very finely-divided and of a very highly inflammable character, the propagation of flame from the shot by the raised dust will only take place to a comparatively limited extent if the atmosphere in which the dust is raised be entirely free from fire-damp.

It is, however, well established that even when the air is quite free from firedamp, an exceptionally inflammable coal-dust, in a very finely-divided and dry condition, and existing in abundance in the immediate vicinity of a blownout shot, may, when raised by the shot, be ignited so readily, and carry on the flame so rapidly, that it may produce explosive effects of a similar character to those caused by a gas explosion. The flame as it rushes along, if fed by freshly raised dust, may extend under these circumstances to very considerable distances, with results resembling in their disastrous nature, those of explosions originating with, and mainly due to, fire-damp.

If a blown-out powder-shot occurs in a locality where the atmosphere contains a small proportion of fire-damp (even not above two parts in 100 of the air), the presence of dry, fine, and porous dust, even if it be only comparatively slightly inflammable, may give rise to the explosive propagation of flame to distant localities where either accumulations of inflammable or explosive gas-mixture (as in goaves or old working places), or deposits of very inflammable dust, may take up the explosion and still further extend its disastrous effects.

Wherever a coal is worked which contains inflammable gas, the atmosphere in the vicinity of the workings, however efficient the ventilating arrangements, will at one time or another, and it may even be said generally, contain some small proportion of fire-damp.

Mines have hitherto been considered free from fire-damp when the search for gas by means of a lamp flame has been unattended by the appearance of a cap upon the flame or by an elongation of the flame. This test, however, fails to indicate the presence of fire-damp, if the atmosphere contains less than from 2 to 2.5 per cent. of its volume of marsh gas.

Such a slight contamination of the atmosphere by fire-damp is not only sufficient to greatly enhance the dangers due to the existence of dust in any abundance in a dry mine-working, as already described, but is also sufficient actually to give rise to the production of an explosive mixture with dust raised in it by a blown-out shot.

Small proportions of gas, such as are referred to, when existing in the atmosphere of a mine, can now be detected, by more delicate gas-indicators than a lamp flame; but, while a knowledge is thus afforded of the presence of gas, it remains impracticable to prevent such slight contamination by fire-damp of the air of a mine near the working places.

Shot Firing.

It will be seen from the foregoing that such contamination, although quite insufficient to constitute in itself a source of danger, does become dangerous if dust co-exists with it, in abundance, in dry mine-workings, if powder-shots are fired in such workings.

No means are at present known by which security can be attained against blown-out shots during blasting in hard coal or in stone, and the use of powder in coal is sometimes attended by the emission of flame, even when blown-out shots are not produced.

It follows from the foregoing that the firing of powder-shots in a dry mineworking where dust exists in abundance must always be liable to be attended with disastrous results if the air in such a locality is contaminated by fire-damp, even to so small an extent as in the proportion of 2 volumes in 100 volumes of the air of the mine.