Shot hole plugging procedure uses plug made from elastomer tube with corrugated walls and blocked end

摘要

The procedure consists of plugging the open end of a shot hole (2) with a plug (10) in the form of an elastomer or rubber bush with corrugated walls and a closed end (16) fastened in place by vulcanisation, thermal welding or rivetting. The plug can be made from a length of corrugated tubing cut into sections and fitted with end walls, each one being inserted into a shot hole by a rod (20). Where necessary, e.g. to change the size of a charge (1n), the plug can be extracted by gripping its edge with a suitable tool.