a. In drilling, a cylindrical opening through the bit shank from which the
circulating fluid is discharged at the bit face into the water ways.
Long
b. Any opening in a furnace through which fuel or flame enters or exhaust
gases escape. ASTM
A plant mounted so that it can be moved over the highways on its own
mounting and that performs all the operations of a stationary plant,
including crushing, scalping, secondary crushing, screening, washing, and
sand separation. Some of these complete plants are mounted on one chassis;
others have the more common operations on one chassis with the
supplementary equipment on separate portable mountings.
Pit and Quarry
Any of several types of self-propelled multibucket loaders that are
considered suitable for miscellaneous light excavating work. These loaders
dig their own path, and to do this, have various means of gathering the
material to a point where it will be picked up by the buckets as they pass
over the lower tumbler. While these loaders are usually used for
reclaiming from stockpiles, they can, under favorable conditions, excavate
from deposits. These machines always are mounted on crawler treads.
Pit and Quarry
portable concentric mine cable
A double conductor cable with one conductor located at the center and with
the other conductor strands located concentric to the center conductor
with rubber or synthetic insulation between conductors and over the outer
conductor. Syn:concentric mine cable
a. A conveyor designed to be moved as a unit. It is commonly wheel mounted
and may or may not be sectional. NEMA, 2
b. Any type of transportable conveyor, usually having supports that
provide mobility. See also:boxcar loader; bucket loader; hatch conveyor;
loading conveyor; movable conveyor; portable drag conveyor;
roller conveyor; trimmer conveyor; unloading conveyor; wheel conveyor.
A hoisting device carried by a frame mounted on wheels. Crispin
A crusher with temporary support foundations, so that it can be moved in
sections, or it can be moved along roadways with minimum dismantling.
SME, 1
A portable conveyor upon which endless drag chains are used as the
conveying medium. Also a term sometimes applied to a portable flight
conveyor. See also:drag-chain conveyor; portable conveyor.
Any size drill outfit that is wheel-, skid-, or track-mounted so that it
can be moved readily as a unit. Long
Self-contained lamp (such as a battery-operated lamp) that may be worn on
the person or carried about freely.
portable flame-resistant cable
A portable cable that will meet the flame tests of the U.S. Mine Safety
and Health Administration.
A loading machine mounted on wheels or crawler tracks.
See also:shovel loader
A motor-driven blower (fan) to provide secondary ventilation into spaces
inadequately ventilated by the main ventilating system; the air is
directed to such spaces through a duct.
An extra-flexible cable used for connecting mobile or stationary equipment
in a mine to a source of electric energy where permanent wiring is
prohibited or impractical. (A portable cable for mining service is not
always extra flexible and is used also with portable as well as with
mobile and stationary equipment.)
portable parallel duplex mine cable
A double or triple conductor cable with conductors laid side by side
without twisting, with rubber or synthetic insulation between conductors
and around the whole. The third conductor, when present, is a safety
ground wire.
portable pneumatic core sampler
A device developed by the U.S. Navy Ordnance Laboratory for sampling coral
and sand bottoms. It consists of a four-legged pyramidal frame about 8 ft
(2.4 m) high, a pneumatic hammer with air supply and exhaust hosing, 400
lb (180 kg) of lead weight, an anvil, and a 4-ft-long (1.2-m-long)
aluminum barrel with a driving head for cutting through coral.
Hunt
A tub-changing arrangement for a tunnel face.
See also:double-track portable switch
A flexible cable or cord used for connecting mobile, portable, or
stationary equipment in mines to a trolley system or other external source
of electric energy where permanent mine wiring is prohibited or is
impractical. USBM, 2
Can. Trail between waterways. Hoffman
a. The rock face at which tunnel driving is started.
Syn:point of attack
b. The surface entrance to a drift, tunnel, adit, or entry.
c. The log, concrete, timber, or masonry arch or retaining wall erected at
the opening of a drift, tunnel, or adit.