supporting of roof by roof bolting ( 1.5m length, 29mm dia ) with mechanical drilling of holes, jamming tightening the roof bolts with bearing plates / w- straps including carriage of material from nearest district store to working faces within a lead o-roof bolting ( 1.5m length, 29mm dia ) by machenical drilling of holes, jamming tightening the roof boltswith bearing plates / w- straps including carriage of material from nearest district store to working faces within a lead of 500 m. ( i ) . materiallike drill rod , drill bitwill be provided by the department. ( ii ) .material like mechanical drill machine / udm , drill cable , etc. will be provided by the colliery management. ( iii ) .arrangement of water & power will be provided by the management . ( for underground ) .