a. A machine for undercutting coal that has the cutter bar fixed in
relation to the main body of the machine. It sumps and cuts across a face
in a more or less continuous motion, except when it becomes necessary to
stop to change the position of the ropes used to move the machine through
the action of rope drums, or when difficulties in cutting are experienced.
Jones, 1
b. A coal cutter that has a long, rigid chain jib in line with the body of
the machine; it cuts across a heading from right to left, being drawn
across by means of a steel wire rope. This machine cannot be readily
flitted from one heading to another unless a power-propelled flitting
truck is available; otherwise each heading requires its own shortwall
cutter. A shortwall cutter will make a 6-ft (1.8-m) cut across a 15-ft
(4.6-m) heading in 20 min, including sumping in and out of the cut.
Mason
A system of coal working sometimes employed in seams 4 ft (1.2 m) or under
in thickness, with the aid of machines. Short faces, each 15 to 30 yd
(13.7 to 27 m) wide, are driven at 50- to 70-yd (46- to 61-m) centers,
with crosscuts to assist coal transport and ventilation. The rippings are
used to form roadside packs. The shortwalls are driven to the boundary,
and the coal pillars are worked by longwall retreating.
See also:shortwall
A trachyandesite composed of olivine and augite phenocrysts in a
groundmass of labradorite with alkali feldspar rims, olivine, augite, a
small amount of leucite, and some dark-colored glass. Shoshonite grades
into absarokite with an increase in olivine and into banakite with more
sanidine. Its name, given by Iddings in 1895, is derived from the Shoshone
River, WY. AGI
a. Coal that has been broken by blasting or other devices. BCI
b. A single explosive charge fired in coal, stone, or ore. Nelson
c. A detonation (or its equivalent) as used in seismic shooting.
See also:gouging shot
d. Small spherical particles of brittle hard steel used as the cutting
agent in drilling a borehole with a shot drill. Also called adamantine
shot; buckshot; chilled shot. See also:gripping shot; blast;
shot drill. Long
A method similar to sandblasting for cleansing the surface of metals,
using broken shot or steel grit instead of sand. Hammond
The act or process of producing a borehole with a shot drill.
See also:shot drill
See:shot drill
a. Incorrectly used to designate a small spherical-shaped drill diamond.
See:drill diamond
b. See:ballas
c. Variety of bort with little impurity, in milky-white to steel-gray
spherical stones with radiating structure and great toughness.
Tomkeieff
d. Spheres of translucent diamond with more cohesion than ordinary bort.
See also:bort
In seismic prospecting, a record of the instant of generation of seismic
waves, as by an explosion. Syn:time break; shot instant. AGI
Small, rounded particles of native copper, molded by the shape of vesicles
in basaltic host rock, and resembling shot in size and shape. AGI
Gunite that commonly includes coarse aggregate (up to 2 cm). AGI
Seismic calculations are usually reduced to a convenient reference surface
or plane. These calculations simulate a condition where the charge is shot
on the reference surface and the energy is also recorded on this same
reference surface. At this reference surface, the time-depth charts have
their origin. AGI
The distance from the surface to the explosive charge. In the case of
small charges, the shot depth is measured to the center of the charge or
to the bottom of the hole. In the case of large charges, the distances to
the top and to the bottom of the column of explosives are frequently
given, and may be reduced to effective shot depth to give the equivalent
of a concentrated charge. AGI
A core drill generally employed in rotary-drilling boreholes of less than
3 in (7.62 cm) to more than 6 ft (1.8 m) in diameter in hard rock or
concrete, using chilled-steel shot as a cutting medium. Also called
adamantine drill; calyx drill; chilled-shot drill. See also:core drill;
shaft drilling. Syn:shot-boring drill
Shafts of up to 5 ft (1.5 m) in diameter drilled through rock to a maximum
depth of 1,200 ft (366 m) by means of a shot drill. The latter makes use
of shot for cutting a circular groove in the rock being penetrated, from
which solid cores are extracted. Hammond
a. Elevation of the dynamite charge in the shothole. AGI
b. The elevation of the explosive charge in the shot hole. Not to be
confused with shothole elevation. AGI
Coal mined by blasting; shot off the solid.
A device to introduce chilled-steel shot, at a uniform rate and in the
proper quantities, into the circulating fluid flowing downward through the
rods or pipe connected to the core barrel and bit of a shot drill.
Long
a. A worker whose special duty is to fire shots or blasts, esp. in coal
mines. A shot lighter. Also called a shooter.
b. In a coal mine, a qualified miner who tests for gas before firing
explosive shots. Pryor, 3
c. See:blaster
A multiple-shot permissible blasting unit introduced in 1948, known as
Capacitor Type Permissible Shot Firer. Weighing approx. 1 lb (0.454 kg)
and about the size of an ordinary flashlight, the nonmetallic unit is
equipped with a belt hook which permits its being carried under
supervision of the shot firer. If desired, shots can be fired without
removing the unit from the belt. It is capacitor operated, eliminating
dependence on speed of operation for energy output. Capacitors supply high
voltage, for a few milliseconds, more than ample to fire from 1 to 10
electric blasting caps. Kentucky
a. The action of detonating or igniting a charge of explosive, usually in
a drilled hole. BS, 12
b. The firing of an explosive charge in a drilled hole to break the
material to a suitable size for loading. Nelson