A should mention that this pic was taken when we were driving the main roadway into a virgin seam that no pit in the country had ever worked,and was waiting to be opened up at the other side of a 36-foot thick Blue Whinstone Dyke,which we would have been driving through within a few days of this pic been taken.
This roadway was 14-feet wide x 10 feet high arched 3-piece girders.
50-odd holes were drilled across the whole of the place ,using a Holman Compressed-air,[windy] driller and a 9 foot long straight [not helix]drillrod,with a "Star" bit on the end of the rod.
Sheer brute force of impact,and rotation,drilled the holes,with a deafening noise from the driller,all shift long,for sometimes 12 hours at a time.[with water/oil being thrown all over you constantly]
It took 50-60 lbs of "Polar-Ajax" explosives,[33% Nitro-Glycerine],to blast this roadway out,to give a 9' "Pull" [advance],in the roadway.
Noo,when ye saw this one after firing,ye had a virtual mountain of shot-down stones to ridd onto a conveyor belt,so in this case we had a small mechanical shovel to shift most of it,but still had to handfill the rest,in order to get the girders in,and prepare the place for bringing the cutter in to cut,and drill again.