In bituminous coal mining, a person who operates a mine locomotive to haul
cars over the main haulage tracks underground or at the surface, as
distinguished from the branch lines. DOT
The principal return airway of a mine. The main return air current
represents the total quantity of air; i.e., after the air splits have
reunited. Nelson
The principal underground road in a district along which mined material is
conveyed to the shafts, generally forming the main intake air course of
each district. See also:main entry
Corn. See:pump rod
The rock above the immediate roof. Obert
The rope that pulls a train of loaded cars out along a haulage plane, as
opposed to a tail rope that pulls a train of empty cars in, as in
main-and-tail haulage. See also:pull rope
This system of haulage is used for hauling loaded trains of tubs or cars
up, or lowering them down, a comparatively steep gradient that is not
steep enough, in the latter case, for a self-acting incline. In the normal
system, a single track only is required. The electrically driven or
compressed-air-driven engine has a single drum that runs loose on the
forged-steel drum shaft; it is controlled by the brake when lowering the
empty train, and is clutched to the shaft by means of a dog clutch when
hauling the loaded train up the gradient. Sinclair, 5
In bituminous coal mining, one who has charge of and rides trips (trains)
of cars hauled in and out of the mine along the main cable haulageway.
DOT
A system of underground haulage in which the weight of the empty cars is
sufficient to draw the rope in. Fay
A wooden or steel door erected near the pit bottom to prevent the intake
air leaking into the main return airway or upcast shaft; a door to direct
the main intake air in toward the workings. It may be fitted with an
appliance, or shutter, to ease the opening for traveling purposes.
See also:fan drift doors
Firing blasts from a mains supply. McAdam, 2
The line of shafting that receives its power directly from the engine or
motor and transmits power to other parts. Crispin
A system of underground mine lighting in which the lamps are fed from the
main electrical supply. It is used principally at the pit bottom, using
filament lamps in either transparent well glass or prismatic bulkhead
fittings. Nelson
In bituminous coal mining, one who operates the hoisting engine for
raising or lowering workers, material, coal, and rock along the main
haulage slope (incline) of a mine having one or more auxiliary or relay
slopes. DOT
In quarrying, consists of the removal by blasting of rock protruding above
the level of the quarry floor or bench, to allow the movement of loading
and transport equipment. Streefkerk
Fr. The face of workings in inclined or vertical seams consisting of a
series of steps each about 6 ft (1.8 m) high, and forming the working
place for one person. Fay
Proper care, repair, and keeping in good order. Crispin
Tension member connecting the feet of a roof truss, usually at the level
of bearing on the wall plate or padstone. Hammond
The conveying or haulage of mined material from the mining area subsidiary
transport to the shaft bottom or surface. For the main transport of coal,
the trend is toward trunk conveyors or locomotive haulage.
See also:subsidiary transport; underground haulage. Nelson
A gangway or principal passage. Fay
See:thorogummite