Blasting holes in open cast mines cast mines
The block to be drilled shall be dozed to remove loose material and boulders.Hole position shall be marked by blasting overman using measuring tape and depth of each hole shall also be marked.Holes shall not be placed in cracked zone.At shift beginning,drill operator shall be check the machine-control,crown block, hydraulic system,brake,lights, emergency trip,availability of the fire extinguisher,hoses not leaking etc.Machine shall not be taken closer than 3meter from bench adge.It shall be at right angles to the edge.Drill shall be levelled and jacks tightened before commencing to drill.Holes shall be drilled at the marked places and to correct depth.Drilling shall always be in retreating fasion I.e.towards the supply switch.While retreating,cable shall be wound on cable reel.If there is no cable reel,it shall be picked up and placed on cable hanger.Cable shall not be dragged over drilled holes.Trailing cable shall not be unfolded from the cable reel fully at least one loo...