Stoping is the process of mining the lode between the levels.
The aim is to extract only the narrow strip of ore-bearing rock, removing as little as possible of the barren rock on either side. The drilling and blasting process used in stoping is similar to that used to develop the drives. Stopers worked in pairs to drill a series of holes in the roof of the stope. Holes were drilled upwards, and explosives were inserted in the holes and the rock was blasted down. Stoping drills were powered by compressed air. The compressed air also expanded the telescopic ‘air leg’ which pushes the machine upwards as the drill hole was deepened.
Advancing the stope
The stope was mined upwards in a series of steps known as benches. As the roof of the stope advanced upwards, the ore-bearing rock that fell to the floor of the stope was left to form a mound. This was the platform on which the stopers stood to drill the next group of holes and blast away the next section of the lode.
Every so often, some of the broken rock would be removed (through chutes known as box holes) at the bottom of the stope, to leave enough room for the stopers to continue working.
The broken rock was removed in one-tonne wagons powered by an electric locomotive engine. 18” (46cm) gauge track was laid underground to allow the mechanical shovels, wagons and locos to operate. The rock was transported or ‘trammed’ to an ore pass.
Photographs reproduced with the kind permission of the Royal Institution of Cornwall and T Grevatt Collection held by Cornwall Council