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ORIGINATING POINT AND POSSIBLE CAUSE OF THE EXPLOSION.

In order to arrive at the cause of a colliery explosion it is necessary in nearly every case to determine the point at which it originated – a matter sometimes fraught with great difficulty – but in no case that we have investigated has it been more perplexing than in the one under consideration. The principal evidence to guide one is that of indications of the direction of force, the presence of flame, the nature of the death which has overtaken the victims of the disaster, and the statements of survivors. So conflicting, however, is this evidence in the present instance that we have been unable to arrive at any definite conclusion respecting either the originating point or the cause of the explosion. We can only put forward the facts as they have come to our knowledge, and carefully weigh the value of each theory that has been advanced in explanation.

On the plans of the working seams accompanying this Report we have indicated the direction of the force in so far as we have been able to determine it, the points at which coked dust was found and on which sides of the props, and also the position of the bodies and whether burnt or not. But the evidence as to force, in so far as it is a means of determining the direction of the explosive blast, is vitiated by the fact that its value is largely destroyed by the succeeding back lash. The names of those who lost their lives in the accident with an indicating number (corresponding with the number on the plan) and the cause of death in each case are given in Appendix A.

Taking a general view of the whole of the seams, we were at first impressed with the idea that the explosion had occurred somewhere in the neighbourhood of the shafts and not inbye at any of the working faces. At first it seemed as though the place of origin was in or about the hauling engine house situate at the eastern extremity of the Straight West Engine Plane in the Towneley seam. To some it seemed possible that it might have occurred in the engine house itself, but more probably that it had originated at the point marked "F" on the plan of the workings of this seam. At this point "F" there was a heavy fall burying beneath it the cable carrying current to the motor driving the hauling drums. The cable came from a distribution box at the downcast shaft along a road which was seldom travelled, but which was an intake airway and close to the downcast shaft. Owing to these circumstances, dust carried from the screens down the shaft in the ventilating current would be present in this road in quantity. Given then a fall, raising enough dust, and an electric arc, owing to some injury to the cable, the whole requirements of an explosion were present. But this idea we were obliged to abandon, for, although on testing the cable it was found that there was electrical connection between two of its cores, its insulation to earth was over five megohms; and, on the fall marked "F" on the plan being ridded, the cable was found intact externally.

Having to abandon this view, we turned our attention to the Brockwell seam, and we still have doubts in regard to this seam, for on the north side of the shafts there were suspicious circumstances as will be recognised by a careful study of the attached plan of the workings.

In two juds on the east side of the North Way, six bodies were found in such positions – and one in particular – showing, apparently, that they had not received any warning whatever of the explosion. The coal was being taken off at a small hitch by juds. The goaf was of considerable area and would possibly contain gas. The lamps of the six men were filled with coked dust outside the gauzes, and the floor of the two places was covered with coked dust to a depth of half an inch or more.

In this Brockwell seam, too, there was the only sign throughout the mine of material having been actually on lire.

But, although in possession of this evidence, we were unable to find any cause of ignition of gas which might have come off at the small hitch referred to or been forced out of the goaf, or liberated from the overlying strata by a heavy fall. That large quantities of gas are sometimes liberated from the strata by heavy falls came under our notice so recently as March last, and this at a colliery where gas had seldom been seen previously.

In addition to our inability to find any cause of an ignition of a possible accumulation or blower of gas, there was evidence which seemed to point to a force having swept inbye prior to any fire or flame having come outbye. This evidence consisted of (a) the condition of the props on the North Way, and (b) the position of the separation door next the downcast shaft. The props in the North Way were not burnt or charred on their outbye side, although on all other sides they were so: the outbye sides were covered with mud, which to all appearances had been thrown on the props by a wave of force prior to fire having come from inbye. The separation door, which in its normal position was on the North side of the downcast shaft, was found blown several yards further North. If the second and more extensive explosion had originated in the Brockwell seam, we think that this door, if found at all, would have been blown to the South or across the downcast shaft.

There was no question of the explosion having originated in the Tilley seam. This left the Busty seam, in which, to our minds, the evidence was so perplexing that we were unable to satisfy ourselves whether the explosion originated in this seam or not. The plan of the workings in this seam shows what evidence there is in respect to force,. &c. There is, however, in addition the evidence of the onsetter, Matthew Elliott, which, as it is the only evidence available from a survivor who witnessed the approach of the blast, and as there can be no doubt that it more than anything else directed the attention of the mining experts to the Busty seam for the possible originating point of the explosion, we produce beneath, the greater part of it.

And for the last three years you have been in the Busty seam? – Yes.

Now, on the afternoon of the explosion were you on the flat sheets near the shaft? – Yes, sir.

And you were on the South side? – Yes.

Did you notice anything particular until you suddenly heard a loud noise? – I just heard a loud noise.

Which side did it come from? – The South.

The South side of the pit at the Busty? – Yes.

Did the sound seem to shake the whole shaft side? – Yes.

Was the shaking very violent? – Yes

Did you hear the tubs rattle? – Yes, as if they had all upset.

That was where? – On the shaft siding.

And that was followed by a big cloud of dust? – The lights all went out.

Probably you would see the dust before the lights went out? – I had a small lamp burning in the cabin, and it showed the cloud of dust.

Did the lights go out before you saw the dust or not? – Before the dust.

Before I leave that about the electric lights, were they electric lights on the South or the North or both sides? – Both sides, sir.

Those lights went out before you saw the big cloud of dust? – Yes.

You saw that by the small lamp? – Yes.

Was it a safety lamp? – Yes.

Was it hanging in the cabin? – Yes.

You heard the tubs rattle as if they were all upset at the shaft siding. That was followed by a big cloud of dust. The electric light on both the North and South sides of the landing went out before you saw the cloud of dust. You saw the cloud by the light of the safety lamp hanging in the cabin. You heard a boy shouting? – I heard a boy shout, "Help me" three times.

You tried to get to your cabin to get some water? – Yes.

Was that for him or for you? – I tried to get it to give him a drink.

But in doing so, you felled yourself against the side of the cabin door. You remember nothing more after that? You were unconscious more or less for a month after the accident? You cannot tell whether the noise came from the West way or the Bugle way. All you know is that it came from the Busty on the South side. You say nothing came by the shaft of the Brockwell. The last person you had spoken to before you heard the loud noise was the pump man, Jack Forster? – Yes.

He was passing you on the flat sheets going to the pump. He asked you the time, and you told him twenty-five minutes to four. You then heard the telephone bell ring. Where did. it ring? – Just round the corner of the shaft.

You went round and found Jack Forster at the telephone? – Yes.

How long was that before the explosion? – About five or ten minutes.

In addition to seeing the lamps go out and the dust did you see any flame? – No, sir.

They were all electrical lights were they not? – Yes.

Prof. Redmayne Did you hear the noise of the explosion before or after the light went out? – Before the light went out.

Was the set of tubs in motion at the time of the explosion? – I cannot remember, sir.

Can you measure the time? How long would it be between hearing the explosion and the lights going out? – I could not say, sir.

Was it almost instantaneous? – Yes, it was instantaneous.

There was no appreciable interval of time between the noise of the explosion and the lights going out? – No.

Do you remember whether the rattling of the tubs or the noise of the explosion was heard first? – I heard the noise of the explosion first.

Could you say whether the other was directly after? – Yes, sir. There was no interval of time.

Mr. R. Kay: Do you know anything about the set being rapped "hold" at the curve? – I cannot remember.

Perhaps you did not hear the rap "hold" at all? – No, sir.

Do you know whether the set was running? – I cannot remember.

Can you tell us whether the set had stopped or not before the explosion? – No.

Prof. Redmayne: If the road was not clear through there being tubs in the way you would have authority to stop the set? – Yes.

Mr. Kay: How many tubs were standing when you heard the noise? – Seven full ones.

The Coroner : Was the road clear to the shaft? – I had four full tubs standing ready to "hang on at that shaft on the South side, but I had plenty of room to get the set to the shaft.

Dr. Thornton: When you heard the noise did you turn in any direction to look or listen? – I just stood.

Were you facing the South at the time? – Yes, I was facing South when I heard the noise. I did not turn my head until I heard the lad Readman shout out.

Which way did you turn then? – I turned east to my cabin.

The Coroner: After hearing the first sound of the explosion, did you hear a second sound? – No.

What was it that knocked you stupid? – I struck my head against the door of the cabin. The door is very narrow and low, and I had to stoop my head in entering.

We are fortunate in having before us the evidence of the mining engineers who were put forward by the owners, viz., Mr. W. C. Blackett, Mr. Simon Tate, and Mr. Philip Kirkup, all men who have on previous occasions investigated colliery explosions and well known in the Northern coalfield for their ability and wide practical mining experience.

The evidence of Mr. Blackett, who arrived on the scene at 8.0 o'clock on Tuesday evening, is very clear and able. He had formed three theories as to the approximate locality of the first ignition The first of these was the Towneley, which became untenable on the fuller ascertainment of facts. The second was in the Brockwell, but he confessed that Elliott’s "direct experience in the mine" shook this. The third was the Busty. The fact that the "whole of the working places and even right into the goaf of "the North side Brockwell appeared to have been filled more or less with flame which " had rushed out by the return to the shaft" made a strong impression on his mind. Mr. Blackett’s evidence continued as follows

"If then both the Towneley and Brockwell seams are absolved from blame, it is necessary to revert to the contemplation of Elliott’s impression being correct, and in that case the only possible point of initiation to be suspected is somewhere in the immediate vicinity of the big fall just round the Busty West way, and the only cause I can conceive is a very thick and heavy cloud of dust being raised by a fall of stone which may have been brought about by an accident to the set which was being hauled outbye and was the cause of it having been rapped hold.

"What has ignited such cloud of dust I cannot say.

"While contemplating the possibility of the ignition starting here I am met with some arguments which I find difficult to answer.

"I cannot honestly say that the position of the baulks under the fall convey to my mind as they do to Mr. Tate’s the certainty that they have been blown outbye. I cannot distinguish such a force from that due to the fall. The crossing about 200 yards from the curve shows unmistakable force going inbye.

"While it is quite easy to trace it inbye here West and inbye to the Tilley drift and Bugle, it is not so easy to understand why, when it reached the shaft, it did not go straight across and up the Towneley staple.

"There are indications of a slighter force having crossed the shaft a short distance towards the North and there are the hangers at the shaft siding bent outbye in favour of this theory, but I cannot quite see why the explosion should prefer to go up the downcast shaft rather than straight on to the Towneley staple. The position of the intumesced dust is on the inbye side of the props, &c., all the way out of West way and past the suspected point of ignition. All the stoppings from the curve to the crossing in the West way had been blown out into the North return, and this return here showed coked dust on the props also on their inbye side.

"The tubs going down the shaft are not conclusive evidence of any direction of explosive force, as the spring of the suddenly released rope could effect all this, and even the hangers might have been bent by an effect from back lash.

"I am informed that the upcast doors at bank blew wide open with the first explosion. It is interesting to try and think whether an explosion in the Busty or in the Brockwell would most readily do this. There is no evidence of disturbance at the upcast pit in the Busty, whereas in the Brockwell there was considerable violence.

"The force of the explosion went up the drift into the Tilley seam and shattered the staple also upwards.

"From the top of the latter it went with great violence into the stables and to the old crossing. "It also went from the top of the Tilley drift for a short distance inbye and then died away.

"Assuming then that the suspicion of the explosion starting near the West curve of the Busty is correct, its course has been – "Westward in the Busty, South into Tilley and Bugle way, North down the shaft to the Brockwell, where it developed in the intakes on both sides, bursting through into the returns ; and up the shaft into the Towneley and down again through the staple to the Busty.

"I am very disappointed that I am unable to give any more definite conclusions, and I regret the somewhat uncertain state in which I must leave the matter.

"I could not have believed that such an explosion could have occurred and developed in all seams without leaving clearer evidence of its cause."

Mr. Tate was more definite; he stated that on his first visit to the Busty seam he was struck with certain indications

"which pointed to the force and trend of the explosion having come along the Busty shaft siding towards the downcast shaft. I afterwards had a strong impression that it had occurred at the Towneley haulage motor, but this latter idea I found was untenable, and after hearing the evidence of Elliott (the onsetter) I had to reconsider my first opinion, and having made further careful and exhaustive examinations, I have satisfied myself that the explosion originated on the South side of the pit in the main intake of the Busty seam at a point beyond the curve at the entrance to the Busty west way.

"I have ascertained that at the moment of the commencement of the explosion the engine set of laden coal tubs was just coming out of the Busty way end and would cause a cloud of coal dust. Just beyond the point where the end of the set had reached and near to the shaft siding there is a fall of stone, and several balks and props under this fall appear to have been driven outbye towards the way end, whereas at a short distance further inbye the indications are all inbye over. I also noticed that the explosive force shown in this neighbourhood, and from thence out over towards the shaft, was not of a very violent character, and there is an absence of any serious damage.

"All the persons employed in the shaft siding and at the pit bottom appeared from the position in which they were found to have had some intimation of the explosion, and most of them had made an attempt to obtain shelter from the blast which was approaching them; thus proving that it was at that moment a comparatively slow travelling force which had just commenced; moreover the bodies did not appear to have been subjected to so much violence as some of the other bodies which were further away from this initial point. We also have it from Elliott that he heard one of the victims crying out for help.

"All these incidents point to the possibility of this point being the neighbourhood of the first ignition; consequently it must be a coal-dust explosion, as gas could not possibly have been present here.

"From this point of ignition the force travelled in every direction inbye to the face of the Busty way, inbye into the Bugle way and up the Tilley staple and up the Tilley drift and outbye to the downcast shaft, and up this shaft to the Towneley seam, and down the shaft into the Brockwell seam. It afterwards came down the Towneley staple into the Busty seam at the other side of the shaft.

"In my opinion it was an explosion of coal-dust which was ignited at a point on the Busty wagonway on the inbye side of the curve."

Mr. P. Kirkup’s evidence did not differ materially from that of Mr. Tate. He said :–

What has been the initial cause of the explosion it is impossible to say definitely. The road is. reported to have been watered the night before, but a quantity of dust would he in the atmosphere from the fact that a full set had just been hauled out against the intake air current (7,240 feet) so that it might fairly be estimated that the whole of the west waggonway from the engine-set near the curve to the in-bye landing would contain minute dust in suspension. The west workings were in two thin seams (top and bottom Busty separately worked) and the laden tubs of coal would contain probably 75 to 80 per cent. of small. The engine-plane at the out-bye end was a gallery driven 30 years ago. It was the oldest engine-place or waggonway which was working on the day of the explosion. The Busty coal has the reputation of depositing dust of a dangerous character. Previous explosions and the recent valuable experiments of Professor Bedson, of the Armstrong College, Newcastle-on-Tyne, published in the Transactions of the Institution of Mining Engineers last year proves this: "Busty dust inflamed at under 700 degrees centigrade ; Harvey or Towneley took 970 degrees centigrade." There is further an incident which occurred at Middleton Colliery in Yorkshire on September 2nd, 1907, and described by Mr. John Neal in the same Transactions. This case was one where the dust given off and raised by a slow horse-drawn set inflamed at an open light, and I doubt not would have resulted in an explosion bad the circumstances been more favourable as regards the fineness of the dust and the character of the same. I simply give this instance to illustrate the dangers of coal-dust, and do not wish to infer that a naked light caused the explosion. There are also instances of where dust has been ignited by sparks caused by the friction of a pulley. All pit dusts have not the same degree of danger. Some ignite more readily than others. The sensitiveness of coal-dust varies as the minuteness of the particles, the gaseous character of the coal, and the exact degree to which these particles are suspended in the air. I much regret I cannot give reasons for a more definite opinion, it is not for want of investigation or time spent in patient consideration of all the available data, but my suspicions centre at a point somewhere immediately on the in-bye side of the west curve in the Busty seam. This is an intake airway remote from the face. It would be impossible for gas to be present here, and therefore nothing but dust alone can account for my supposition, but what was the initial igniting cause of the inflammation of dust which resulted in such a terrible disaster, I am unable to say.

As to the possible means of ignition the following have to be considered

(1.) Open lights, whether defective lamps or matches.

(2.) Shot-firing.

(3.) Sparking from mechanical friction.

(4.) Electricity.