EIACP (PC-RP) on Environmental Problems of Mining

Bhowrah Colliery

This accident occurred at night. Some pillars in 14 seam, situated between two inclines, suddenly collapsed and the surface ground above them subsided to a depth of 3 to 3.6 m over an area measuring 60 m x 58 m. On or near this area of ground were three rows of miners’ “dhowras”. The eastern row, being just outside the subsided area remained intact. The middle row went down vertically with the subsided ground and the occupants were uninjured. The western row collapsed completely because, being near the edge of the excavation, it was tilted. About 45 persons were asleep in this row and out of them 7 men, 9 women and 8 children were killed, being buried under the debris of the fallen building.

14 seam at this colliery was 8.7 to 12 m thick and was steeply inclined at in 2.87. After the collapse it was seen that the roof consisted of jointed shaly sandstones with prominent vertical cleavages which must have developed at the time of faulting on the dip side of the workings. The seam had been developed by driving galleries 3 m wide and forming pillars 13.7 m x 10.7 m, corner to corner. Complete extraction of these pillars was not contemplated because if the surface was disturbed, water would have got into the workings in the vicinity. The Manager therefore decided to split the pillars by driving galleries 3 m wide x 3 m high through the pillars in both directions thus dividing each pillar into four stooks of 5.3 m x 3.8 m. In the area which collapsed, such partial extraction had been carried out in all the pillars except six pillars. Even out of these six pillars, splitting had been commenced in five.

The Court which inquired into this accident was of the opinion that extraction of the planned amount of coal would not have endangered the surface. Probably a good deal more coal had been extracted than was arranged by the management. During the inquiry, the Overman admitted that he had several times reported cases of pillar robbing to the Manager. He further admitted that the height of some of the splits was 4.5 m and many of the stooks left were not more than 3 m x 3 m. The Under Manager stated that he had certainly seen galleries wider than originally driven and that he had not inspected for a fortnight the fenced-off areas where splitting had been finished. He also spoke of falls from pillars. The Manager had not inspected for a long time the splits which had been fenced off.

The Court came to the conclusion that at some place the pillars had become too weak to sustain the pressure of the overburden and the collapse had started at this place. Collapse of these pillars had upset the balance and the remaining pillars in the area got overloaded and therefore collapsed. The great height of the pillars, extending upto 10m in some cases, was an important factor in bringing about such collapse.

The Court held the Overman and the Mining Sirdar primarily responsible for allowing miners to drive splits of width and height greater than 3 m and for not preventing the robbing of pillars. The Under Manager’s inspections were considered worthless from the point of view of stability of the workings. However, the chief responsibility for the death of these persons was fixed on the Manager. He was undoubtedly trying a new experiment underground in splitting the pillars in this way. Experiments such as this may succeed or may fail. If the dimensions originally designed were not conformed to, failure was more probable. In such circumstances, the Manager should have got the “dhowras” vacated. However, the Court was satisfied that the Manager himself had no suspicion that the accident was likely to occur, otherwise he would have ordered removal of the large number of tubs that were lost in the collapse.

Also, the Manager satisfied the Court that there was no lack of “dhowra” accommodation at the colliery and he could have easily transferred these people if he had apprehended any danger to the occupants of these “Dhowras”.