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None of the provisions either of the Coal Mines Act, 1911, or of the General Regulations of 30th July, 1920 (Part Il-Precautions against Spontaneous Combustion of Coal), made there under, appear to have been contravened, unless it be in connexion with the discovery of the active fire outbye G.1 stopping, in July, 1940. Strictly according to the law, as soon as that fire was discovered all persons engaged inbye of Lowca Junction should have been withdrawn, and the provisions of 9 (1) of the above-mentioned Regulations should have been complied with. There was, in fact, no withdrawal as the danger, if any, was dealt with at once and was short-lived. It seems reasonable also to suggest that it was removed before the procedure of withdrawal could have been completed.

In Section II, "Events leading up to the Explosion," pains were taken, as far as possible, to avoid expressions of opinion regarding the steps which were taken from time to time in fighting what later events have shown was a losing campaign almost from its outset. Facts only have been given and, as will have been observed, there were facts in abundance, in the face of which it is almost a matter for wonder that the last defence line was not voluntarily surrendered before the complete defeat on 3rd June.

From the beginning physical conditions were such as almost to make the ultimate failure a foregone conclusion. To start with, there was the formidable array of inlets and outlets (upwards of 100 including some which are not designated) to be sealed, and the seals thereafter to be maintained, in ground already weakened by the working of the coal, the coal itself being also weakened by the robbery and splitting of pillars of meagre dimensions in their original state.

It is easy to say it now after the event, but it is clear that as soon as active fire became manifest at G.1 and H.1 in July, 1940, the only hope of survival lay in the provision of a really effective seal on the intake side, followed by something equally effective at the foot of the Countess Bannock Drift. Nothing short of the complete stowage by hydraulic means of all the old bords in the Main Coal Pillars between the ring of stoppings and the 7-fathom fault would have served. Indeed, the possibility of the need for this step had not been overlooked, for Mr. John Williamson, General Manager, when speaking in evidence of the object in view in building the New Front stopping stated: " We had another object in view, that being if the New Front stopping had to be sealed we intended to bore off the Countess Drift with the water supply we had and fill that whole area up with sand and flue dust." He proceeded to add that: "We did not feel we were anywhere near a decision that called for steps like that to be taken."

A matter of more than passing interest is the effect of the recent workings of the Bannock Seam, started in 1935, on the old Main Band pillars immediately below. The sudden recurrence of gob-fire trouble after a respite of about 14 years is strange and can only be accounted for by some change in conditions that had apparently become stabilised.

It is not unreasonable to assume that the recurrence of the trouble was not merely a coincidence, but that it was closely associated with the development of the workings in the Countess Bannock Band. The recorded position of the last heating, that in 1924, as shown on Plate No. 2, coincides with a point about halfway to the face along the main gate of the No. 6 Rise Face in the Countess Bannock District. There can be little doubt that the state of equilibrium of the strata supported by the Main Band pillars was upset, with detrimental effects on the old stoppings built in 1924 to isolate that heating. Some confirmation of this conclusion is to be derived from evidence regarding explorations to trace the source of the carbon monoxide which appeared in the main return airway in December, 1938. On the 23rd of that month a sample of air taken in Lowca Level four pillar lengths inbye of the site of what later became stopping A, – previously there existed here a stopping with a door in it – contained 0.26 per cent. of carbon monoxide, which rather points to a recrudescence of the earlier heating.

The finding that this calamity was caused by an explosion of water gas produced by the application of water in unusual circumstances to burning coal which had become ignited by spontaneous heating, is bound to create some misgiving as to the possibility of a similar danger arising when water is used for ordinary "Fire-fighting" operations belowground. The main standby for fighting fire belowground has to be an ample supply of water; there is no effective alternative except for quite small superficial fires. If, however, the effect of putting water on fire is to be to produce volumes of explosive gases, does this not, as was aptly put by Mr. T. Cape in cross-examination of Professor Poole, "open up a new phase of danger to be faced in the mining world to-day?"

Prima facie the reply would appear to be in the affirmative. But the affirmative cannot be accepted without considerable qualification, based firstly on experience and secondly on consideration of the factors which are essential to the production of water gas in dangerous volume.

The accumulated experiences of more than a generation in fighting, by means of water, all sorts of fires, large and small, in all kinds of conditions and circumstances underground, certainly suggests that the risk of a dangerous water-gas explosion is very unusual and even remote. Such an explosion cannot occur unless there are concurrently (a) a large mass of red hot carbonaceous or coaly material, (b) a supply of water which on conversion to steam remains for an appreciable time in close contact with the hot carbon, (c) partial confinement to a space in which mixture of the water-gas with air takes place and (d) contact with the explosive mixture of water-gas and air with some igniting medium. These essentials are not likely to occur except when a fire is deep seated in a mass of coal.

Whilst it may perhaps be dangerous to dogmatise, the opinion is here definitely expressed that in the case of deep-seated spontaneous fires, treatment by water can only be promiscuous and it may also be hazardous. In any event, water cannot be relied upon as a curative unless it is applied in such quantity as to cause complete immersion. The William Pit explosion is a striking example of this thesis.

As regards deep-seated fires arising from other causes, care in the application of water is clearly called for where there is a possibility of the production of "water-gas". Within the limits of this report it is impossible to discuss or attempt to define the conditions which may give rise to the risk of a water-gas explosion and the precautions to be taken. It is, however, important that an attempt to do so should be made, and to this end I recommend further investigation and perhaps research.

In conclusion, I desire to acknowledge my indebtedness to all parties who took an active part in the Inquiry for their assistance and collaboration in expediting the proceedings.

I desire also to express regret for the delay in submitting this report. Pressure of other work, both in the case of myself and of the Assessor, has been in the main responsible for this delay, which has, however, been aggravated by my own ill-health.

I have the honour to be,

Sir,

Your obedient Servant,

F. H. WYNNE

H.M. Chief Inspector of Mines.