In mine subsidence, the strata lying over the excavated area.
Briggs
a. Dust from rock drills, blasting, or handling rock. Fay
b. In the quantity inhaled by workers, dust may be classified as
dangerous, harmless, and borderline, although the classification is purely
arbitrary. Silica is a dangerous dust and aluminum hydroxide is
borderline. Lewis
c. Scot. Calcined ironstone screenings. Standard, 2
d. See:coal dust
In mine subsidence, the mined area multiplied by the mean thickness of the
bed, or of that part of the bed that has been extracted. Briggs
See:fire boss
See:mining engineer
a. The main fan for a mine; normally situated at the surface.
BS, 8
b. A radial- or axial-flow ventilator. See also:fan; ventilation.
Nelson
A system that indicates by electric light or electric audible signal, or
both, the slowing down or stopping of a mine ventilating fan.
A conductor or group of conductors, including feeder and sectionalizing
switches or circuit breakers, installed in mine entries or gangways and
extending to the limits set for permanent mine wiring, beyond which limits
portable cables are used.
See:hydraulic fill
This very dangerous occurrence may arise as the result of spontaneous
combustion, the ignition of timbers by gob fires, electric cable defects,
or the heating and ignition of conveyor belts due to friction.
Nelson
Designed to fight underground fires in mining operations, this low slung
railcar is equipped with a water supply and pressure equipment for its
fire hoses. When a fire occurs, the car can be sped to the scene along
existing rails. The truck is capable of delivering hundreds of gallons of
water, depending upon the size and model used. Best, 1
a. The person charged with the responsibility of the general supervision
of the underground workings of a mine and the persons employed therein. In
certain states, the mine foreman is designated as the mine manager.
See also:foreman
b. Generally used to designate that company representative in complete
24-h charge of underground workings and legally held responsible for the
safety and welfare of all underground employees. The foreman is generally
State certified for competency. BCI
c. A deputy in metal mines. Nelson
d. An official in charge of plant and associated labor on the surface,
e.g., screen foreman. Nelson
A stratum or group of strata containing layers of ironstone.
See:pithead
In a mine ventilation system, the cumulative energy consumption is called
the mine head. A head is in reality a pressure difference, determined in
accordance with Bernoulli's principle. Hartman, 1
A device for raising or lowering ore, rock, or coal from a mine and for
lowering and raising workers and supplies. See also:hoist
This mechanism is designed to prevent accidents in mine cages caused by
overspeeding in hoisting and lowering. It also prevents hoisting or
lowering beyond the limits for which the controller is set. On electric
hoists, it can apply a brake in case of power failure and may regulate
brake speed in the event of an emergency stop. Best, 1
a. Person who checks mines to determine the safety condition of working
areas, equipment, ventilation, and electricity, and to detect fire and
dust hazards. Webster 3rd
b. Generally used as denoting the State mine inspector as contrasted to
the Federal mine inspector. See also:inspector
Pig iron made entirely from ore; distinguished from cinder pig.
Standard, 2
A special electrically driven car for underground transportation of
officials, inspectors, repair, maintenance, and surveying crews and rescue
workers.
Battery operated lamp; may be attached to a miner's cap to provide
illumination in poorly lighted mine areas. Lamps are designed to focus on
working areas when attached. A unit consists of a rechargeable battery,
bulb, reflector, wires, etc. Mine lamps may be purchased outright or
leased. Models include cap lamps, hand lamps, and trip lamps.
Best, 1