Rock shaft

Rock´ shaft`


1.(Mach.) A shaft that oscillates on its journals, instead of revolving, - usually carrying levers by means of which it receives and communicates reciprocating motion, as in the valve gear of some steam engines; - called also rocker, rocking shaft, and way shaft.
References in periodicals archive ?
This summer the Rock Shaft Head Tower at the mine was demolished as part of a major redevelopment.
The first step will see a PS16m programme this summer to replace the Rock Shaft Head Tower at Boulby which will significantly increase its maximum production potential.
The BNC s maintenance works include the main rock shaft bunton sets, key rock shaft ore, bin and waste conveyors, crushing plant steel structures, electrical panels plus electric cables, revamping crushers, conveyors with screens as well as hot commissioning of crushing circuit.
A CAVE-EXPLORING pensioner had to be rescued after falling down a rock shaft and getting stuck overnight.
SOB is a man and rock shaft that delivers ore to a 7,400 t/d surface crusher.
Shafts have produced both fluorite and zinc; the deepest on the property is the Rock shaft, 240 feet deep.
But now the Rock Shaft Head Tower at Cleveland potash mine has been demolished as part of a major redevelopment.
A series of probes are being launched into the dumping of nuclear waste in Dounreay's notorious doomwatch rock shaft.
Speirs, Innovation and Perseverance Breaking New Ground in Hard Rock Shaft Sinking in the 1990s, CIM Annual Convention, Ottawa, Ontario, 6-10 May 1990.
Replacing the rock shaft head tower will cost an estimated PS16m and is part of the redevelopment announced in April by ICL, which owns the mine at Boulby.
One of the first steps will involve a PS16m programme this summer to replace the Rock Shaft Head Tower at Boulby.
The shafts have been sunk using a combination of methods: slurry wall excavation of the over-burden, followed by drilling and blasting of the rock shafts and starter tunnels.