B Words

the method of extracting the lode by means of benches being drilled and blasted, with the extraction proceeding upwards, the miners standing on the broken ore from previous blasts. Periodically the broken ore requires ‘pulling’ to make sufficient room for work to proceed, broken ore taking up 50% more room than before it is broken out.

the surface part of a shaft also known as the collar, the area around the shaft head.

the person responsible for carrying out the duties and operations required at the shaft head.

a method of holding a rock drill in a specific position, comprising a substantial screw jack bar between the floor and the roof with a moveable horizontal bar clamped to it. The rock drill is mounted on a screw feed cradle that is clamped at the required position on the arm.

a substantial brattice or fence to prevent inadvertent access to a danger area, for instance a hole in the floor, stope edge, or old unventilated workings etc..

the common wheel barrow, used extensively up to the 1970’s for mucking out small or inaccessible workings, i.e. long inters.

a mass of plutonic rock, such as the granite masses in and around which the main ore bearing lodes occur in Cornwall.

The step in any sort of stope, generally the length of the drill steel being used.

The part of the rock drill that is in direct contact with the rock being drilled. The action of which is to pulverise the rock.

a) Button bit: A bit in which are set a number of hemispherical pieces of tungsten carbide
b) Chisel bit: A bit in which one piece of tungsten carbide is set across the face of the bit.
c) Cross bit: A bit which is set with four pieces of tungsten carbide, arranged ina cross on the face of the bit.
d) Diamond bit: This bit is generally a thin walled tube with small fragments of industrial diamonds fixed into one end of the tube. The bit is revolved at high speed against the rock surface to produce a core for geological purposes.
e) Knock on/off bits: A detachable bit that is fixed to the end of a purpose made drill steel. A copper thimble is used to enable the bit to be knocked off for sharpening.
f) Reamer bit: A knock on/off type bit used for drilling large diameter holes with hand held rock drills, usually for the empty holes in a burn or cylinder type cut.
g) Rope Thread bit: Detachable bits of various types with a coarse thread for attachment to rope thread drill steels via collars. These are used when a long hole string of steels are required for long hole drilling.
h) Tungsten Carbide bit: The bit was formerly hardened steel but tungsten carbide became the most commonly used material from which bits are made.

blasting         

The term used for the use of explosives to shatter rock in mining operations

Once a chute was no longer required the extraneous timber work was removed to leave the stulls and brow. Planks or half pieces were then used to fill in the remaining area to prevent rock dropping through from above, with the drive cleared of the box  part of the shute.

A line of, generally, stope chains hanging from eye pegs in the back to which are attached planks, steel sheeting, lengths of old conveter belting etc., to protect more sensitive areas from rocks thrown during blasting operations.

A term for a detonator (also known as a ‘DET’) though in Cornish mines it was generally called a cap.

A length of square section timber up to 4 metres long, either used alone, or attached to others, to which a bomb is securely attached. The staff is then pushed up into inaccessible places to bring down hung up rock in boxholes, drawpoints, or passes.

Mud Blasting is a term used in secondary blasting when, after an explosive charge was placed on a rock, a cap of thick mud was slapped over it to enhance and direct the force of the explosion into the rock.

A number of long holes in a ring or rings blasted using millisecond delay detonators. The mine was generally cleared of all other personnel at this time. Some blasts comprised of up to a tonne or more of explosives loaded into 30 or 40 holes up to 25m long.

generally a pair of three sheave blocks rove with good quality rope to facilitate lifting heavy materials & equipment in remote places.

these are used as a set of three. Each ‘rod’ is a short length of lath with another piece set at right angles on one end. All are the same length and are used by looking through the three over a distance to enable a straight line to be accurately sighted

the arm on which a hydraulic or large compressed air drill and cradle is mounted. The boom can be hydraulically adjusted to position drill.

a term rarely used at South Crofty, for a timber chute.

‘Break out arse’, Expression used to indicate a round has broken out to the full extent of the hole depth, leaving few or no sockets.

the holes in a development round at chest height outside the cut and easers and within the side holes.

a term sometimes used for a rill stope, whereby the stope face was advanced from the rearing, with the drilling generally horizontal.

The edge over which broken rock moved to enter the box part of the chute.

Most timber chutes had a length of GWR held by heavy duty staple like spikes to act as a wear resistant brow piece.

A term for anything that holds water, rock or whatever.                                   
a) Mucker bucket:- The scoop part of an air shovel which picks up the broken rock.   
b) Sinking bucket:- Traditional shaped bucket holding a tonne or more of broken rock, and in conjunction with a framework on guides, used to hoist broken rock in sinking operations to a suitable discharge point.
c) Spillage bucket:- Similar to above and used to load spillage from the skip loading operations to a suitable discharge point.
d) Powder bucket:- Rubber bucket fitted with a wood lid and carrying rope, used to transport explosives between reserve station & work place.

a bundle of short, thin and stiff wires in a small holder, carried by most mineworkers in the days of carbide lamps. It was used to clear the gas jet of the lamp if it became clogged.