Said of a system of mining in which typically flat-lying beds of coal or
ore are mined in rooms separated by pillars of undisturbed rock left for
roof support. See also:bord-and-pillar working;
County of Durham system. Syn:heading and stall
In coal and metal mining, supporting the roof by pillars left at regular
intervals. Lewis
room-and-pillar with waste filling
See:overhand stoping
In bituminous coal mining, a miner who inspects the working face in
working places (rooms) to determine whether mining operations are being
carried on properly and safety regulations are being observed. Also called
wall boss. DOT
a. Any conveyor that carries coal from the face of a room toward the
mouth. Normally, a room conveyor will deposit its coal into a car or
another conveyor at the mouth of the room, but occasionally it will dump
into a cross conveyor at some point between the face and the mouth.
Jones, 1
b. See:underground mine conveyor
Any entry or set of entries from which rooms are turned. A panel entry.
A short passageway from the mine entry to the room in which a miner works.
See:bord-and-pillar
A monoclinic mineral, BiAsO4 ; monazite group; at Santiaguillo,
Bolivia.
See:underclay
A lode or vein from which alluvial cassiterite or gold may have been
derived.
a. A towed scarifier; sometimes used to break up a hard surface and prior
to the use of bulldozers in removing overburden at quarries and opencast
pits. A heavy-duty ripper. Nelson
b. A towed machine equipped with teeth, used primarily for loosening hard
soil and soft rock. Nichols, 2
A very heavy hook designed to catch and tear out big roots when it is
dragged along the ground. Nichols, 1
The root-mean-square value of an alternating current or voltage. It is the
square root of the mean value of the squares of the instantaneous values
taken over a complete cycle. When an alternating current or voltage is
specified, it is almost invariably the root-mean-square value that is
used. Also used of quantities that alternate over longer periods, for
example, a month or year. Also known as effective value. Abbrev., R.M.S.
CTD
A conveyor consisting of a rope with disks or buttons attached at
intervals, the upper flight running in a trough. The coal or other
material is dropped into the trough, and the conveyor either is actuated
by the weight of the coal in the trough when the trough is inclined
forming a retarding conveyor, or moves the coal along the trough where the
gradient is insufficient or adverse. In the one case a brake is provided;
in the other, the sprockets are actuated by a motor. Zern
An important component of stranded ropes is the core, which may be either
of fiber or of wire. In winding ropes it is generally made of manilla,
sisal, or hemp. The function of the core is to support the strands and
prevent them from bearing hard against one another. An even more important
function is as a store for lubricant for the interior of the rope, and
during manufacture it is saturated with lubricant. Sinclair, 5
See:hook tender
The diameter of a steel wire rope is the maximum obtainable measurement
across the outer edges of the strands. The size of fiber ropes is usually
specified by their circumference. Modern steel wire winding ropes are
large and heavy and may be 2-1/4 in (5.7 cm) in diameter for a moderately
deep shaft. Nelson
In bituminous coal mining, a foreperson who looks after the haulage cable
and the equipment of trains of cars by which coal is hauled from the mine.
The rope driver superintends the attaching of cars to cable by clipper and
directs movement of the cable by signaling a slope engineer through a
buzzer system. DOT
The transmission of power by means of rope gearing, as distinguished from
belt drive. Crispin
Any drum, powered or otherwise, on which rope is wound; e.g., mining
machine rope drums, room hoist rope drums, etc. Jones, 1