There was only one serious accident due to an explosion of firedamp, and this caused the death of three persons. The accident occurred at the Wellington Pit, Whitehaven, in the back drift of a pair of drifts being driven landwards from the Saltom District of the Main Band Seam to connect with a pair of similar drifts being driven seawards from Haig pits belonging to the same owners, the Whitehaven Colliery Company. These drifts will ultimately form the intake air and haulage roads of the Haig pits now being equipped to win the coal from the present Wellington pit area. The drifts, which were 54 yards apart, had been driven landwards for a distance of 750 yards, of which 500 yards were in stone. They were 13 ft. wide and 9 ft. high inside the timbers, were driven level, and for the last 300 yards had gone through very faulty ground. At the time, the front drift was standing owing to lack of men and was in freestone, while the back drift was being driven to prove the ground ahead and was 54 yards in advance of the front drift.

Stentons 6 ft. by 6 ft. were driven about 50 yards apart, and the last stenton was 28 yards from the face of the front drift and 82 yards from the face of the back drift. A current of 4,000 cubic feet of air per minute was passing into the drifts, which had a separate intake and return airway, and was carried forward from the last stenton to the face by means of canvas tunnels 6 ft. high and 4 ft. wide formed of a canvas roof and sides. The tunnels were 10 yards and 23 yards from the face of the front and back drifts respectively. In the front drift the canvas tunnel formed the intake, while that in the back drift formed the return. The arrangement is shown on the sketch.

A seam of coal 1 ft. 5 in. in thickness, rising with an inclination of 1 in 7, was proved in the floor of the back drift, 18 yards from the face, and as the drift was level the seam was near the roof at the face. The drift had been driven at its full height of about 10 ft. 6 in. to within 13 yards of the face, where a top canch of 3 ft. had been left, to be followed up behind as the girders were put in.

At the end of the shift prior to the accident, between 10 a.m. and 11 a.m., a round of shots had been fired. Two of the shots were in the coal and six were in the stone. These shots were fired at the face of the drift, and the debris was left lying for the next shift of men to clear away. At the time of the accident there were seven men and a shotfirer working at the drift. While the men were clearing away the debris from the shots, the chargeman, Goodwin, one of the injured men, bored a shot-hole in the left side of the drift 13 yards from the face near the floor and below the cavity formed by the top canch, in order to square back the side to the finished width of the drift. This hole was bored at an angle of 45 degrees, to a depth of 4 ft. 6 in., and passed through the seam of coal into the fireclay beneath for a distance of 6 in. This hole was charged with 12 ozs. of Samsonite explosive and fired with a No. 6 detonator electrically. Two men — W. Graham, the shotfirer, and S. Goodwin, chargeman — took refuge in a refuge hole 40 yards from the face of the drift and 27 yards from where the shot was fired, whilst the three men who were killed went back to the chest in the stenton. The other three men were about 300 yards from the face of the front drift taking full tubs out which had been filled. While the men were taking refuge the shot was fired by Graham, but it did very little work, as it struck off a slippery joint in the fireclay at the bottom of the hole and the majority of the debris was blown across to the other side of the drift. The coal appeared to have been powdered by the shot and it was probably projected in an incandescent state into firedamp that had more than likely accumulated in the cavity in the roof immediately above the shot, and either this fine coal dust or the flame from the explosive itself caused an explosion of some violence.

The whole of the brattice in the back drift and a large portion in the front drift was blown down and a number of props in both drifts dislodged. The deceased man, Ashbridge, was projected through the stenton and thrown against the far side of the front drift, and was dead when found; Corkish was knocked against the side of the drift and sustained injuries from which he died while being taken out of the pit, while Connor sustained injuries and severe burns from which he died the same night, about seven hours later. The chest at which the men were sitting was also hurled through the stenton into the drift front and badly broken, and there were signs of force nearly 600 yards away on the front drift and about 200 yards away on the back drift. An air crossing in the front drift, 588 yards from the seat of the explosion, had the floor lifted bodily three-quarters of an inch.

Owing to the floor of the drift being wet and stone dust being on the sides and roof timbers, there were no indications of flame on them, but the men themselves were much burnt, especially Connor. The presence of stone dust on the sides and roof was due to the use of compressed air percussive boring machines at the faces of the drifts.

The shot-firer stated that he examined for firedamp before firing the shot, but it was quite evident from the explosion which followed that his test had not been accurate or that he had omitted to test in the cavity which he could not reach without a staging or standing on a tub, as it was 10 ft. 6 in. to the top of it from the floor. The judgment of both the shot-firer and the chargeman was at fault, first in drilling the hole at this point and then in firing it after it had been drilled.

There can be no doubt that firedamp was present if not at the face at any rate in the cavity above the shot, and that the shot, being badly placed and, therefore, overcharged through having so little work to do, ignited the gas and caused the explosion.

The canvas being back from the face and also the fact that the top of the canvas tunnel would be at least 4 ft. from the roof would allow gas to accumulate near the roof, although a good current of air might be passing into the drifts. If the canvas tunnel in the back drift had formed the intake as it did in the front drift, there would not have been the same tendency for the gas to accumulate as there was when it was used as the return.