Drilling

This involves drilling of support holes and installation of resin bolts.  The bolter drills 1.8 metre holes which are 33mm in diameter. The  supported end is marked reef, then marking of drill hole positions  is done in preparation for face drilling.

 

Face drilling is carried out using hydraulic face rigs. After drilling,  holes are cleaned and any grit material is fl ushed out before  charging with cartridge explosive. Ammonium Nitrate is then  pumped into the holes using compressed air.

 

The charged holes  are timed to ensure firing starts at the cut holes, before moving out  to the rest of the end holes.