Date of the Accident– 15.10.1910
Owner– Bengal Coal Co. Ltd.
Number of Persons Killed– 12
Place– Raniganj Coalfield
The circumstances attending this accident were of a very unusual character. Pillars were being extracted in the Dishergarh seam which was 6 m thick and lay at a depth of about 90 m. Immediately above the coal was 1.2 m of shaly sandstone which was overlain by hard and massive sandstones right upto the surface. Owing to the tender nature of the shaly sandstone, 1.5 m of coal was left under it to provide support to it. During depillaring it was found that the shaly sandstone along with its coal support used to fall down immediately after withdrawal of the timber. At times, its collapse might be delayed by a few hours but the delay had never exceeded two days. The hard sandstone roof above, however, remained unaffected even after large areas of coal had been extracted.
Depillaring had been going on for 18 months and an area of over 22,000 m2 had been extracted; yet the main roof had not fallen in any part of this area. The accident was caused by the fall of the immediate roof over a small area.
The accident occurred at 7.15 p.m. on Saturday, the 15th October. On Friday morning a stook was being reduced and by noon the work was completed when it was reduced to a size of about 1 m x 0.5 m. By evening all timber in this area was withdrawn. Crush on the left over stook was noticeable at this time showing that the roof was being strained. No further work was done that night.
Early on Saturday morning the Assistant withdrew timber from a neighboring stook and here the roof fell immediately. An hour later the Manager arrived and he saw that the roof of the stook which was extracted on Friday was still standing except for a small patch near the left over portion of the stook which had crushed. He saw that about 15 tonnes of roof coal was lying in this goaf precipitated from the recent collapse and he was tempted to take that coal out. The roof appeared to be sound and he issued order for the area to be re-timbered. At 5.30 p.m, the Assistant reported to the Manager that the place had been re-timbered. A little before 7 p.m., 24 miners were engaged under the supervision of a Mining Sirdar to load the fallen coal. At 7.15 p.m, the roof collapsed suddenly without any warning killing the sirdar and 11 miners and injuring 2 others. Only those carrying coal to the tubs escaped.
This wholesale sacrifice of human lives arose out of the greed to get 15 tonnes of coal quickly regardless of the obvious danger incurred. The miners were admitted to work in a goaf from which timber had once been withdrawn. The re-setting of timber must have been carried out under conditions of danger and this course of action was pursued in spite of the experience possessed by the manager of the treacherous nature of the roof. There was no proof of the number of props which were re-set as the fall had buried whatever there might have been.
If the props in the goaf had been demolished by the vertically applied weight of the roof, the cracking of timber would have given ample warning of the impending danger. But as there was no such warning, what might have happened is that owing to the slope of the previous fall, it was not possible to set timber right to the goaf edge in consequence of which the unprotected roof had heeled over and the timbers were in this way knocked out.
The Manager, who held a Second Class Certificate of service, was managing this mine under a temporary authorization granted by the CIM. After this accident his authorization was withdrawn.