A rounded stone or pebble, commonly highly polished, from the stomach of
some reptiles, esp. dinosaurs, plesiosaurs, and crocodilians. Gastroliths
are thought to have been used in grinding up food, but marine reptiles may
have used them to provide body stability while in the water. AGI
Any mollusk belonging to the class Gastropoda, characterized by a distinct
head with eyes and tentacles and, in most, by a single calcareous shell
that is closed at the apex, sometimes spiralled, not chambered, and
generally asymmetrical; e.g., a snail. Range, Upper Cambrian to present.
AGI
See:weeksite
In bituminous coal mining, person who makes morning examinations for gas
before workers enter the mine. See also:fireman; fire boss; gasman.
DOT
Water through which coal gas has been passed and which has absorbed the
impurities of the gas. Fay
a. Eng. Gateway or gate road. A road or way underground for air, water, or
general passage; a gangway. See also:gate end
b. Eng. A road packed out in longwall goaf. When ripped in the waste to
provide packing material on a conveyor face, it is called a dummy gate.
Also called gate road; gateway; main brow; trail road. SMRB
c. The apparatus at the bottom of an ore chute for filling cars. Also
called a chute. Spalding
d. Syn:swivel head
diamond drill. Long
e. The closing piece in a stop valve. Standard, 2
f. A valve controlling the admission of water to a waterwheel or conduit.
Standard, 2
Conveyor usually from 26 to 30 in (66.0 to 76.2 cm) wide and troughed so
as to centralize the load and minimize spillage. A scraper feeder,
consisting of an elevating chain conveyor driven by the gate belt, is
often used to transfer the coal from the face belt to the gate belt.
Mason
A gate road conveyor that carries coal from one source or face only; i.e.,
from a single-unit or double-unit face. See also:conveyor;
face conveyor; gathering conveyor. Nelson
The coal face or inby end of a gate. See also:gate
A flameproof enclosure primarily for use at or near the coalface and
designed to line up with similar boxes to form a control board. A gate-end
box may contain bus bars, isolators, switches, contactors, transformers,
and protective devices, for the control of motors, lighting, and other
equipment. Syn:gate-end unit
A short conveyor that feeds the coal from the face conveyor onto the gate
conveyor. See also:feeder conveyor
A short conveyor designed to receive the coal from the face conveyors and
elevate it to such a height as to be convenient for delivery into mine
cars. See also:feeder conveyor
A flameproof motor-starting contactor for use with coal-face machinery.
The essential features are a flameproof casing divided into two separate
compartments, the smaller of which contains a hand-operated isolating
switch and the main bus bars. The isolating switch is interlocked with the
cover of the main compartment so that it cannot be removed unless the
switch is in the off position; or it may be fitted with contacts enabling
the mechanism to be earthed before work is undertaken on it. Mason
See:gate-end box
A system designed to prevent shaft conveyances from being moved or action
signals from being transmitted, unless all shaft gates are closed.
BS, 13
a. Eng. A road connecting a stall with a main road. Standard, 2
b. A road through the goaf used for haulage of coal from longwall working.
Pryor, 3
An appliance for the storage of coal from the face conveyors during peaks
of production or during a stoppage of the outby transport. It may consist
of a length of conveyor chain running in high-capacity pans arranged under
the delivery end of the gate conveyor. When the trunk conveyor cannot
handle the coal from the gate conveyor, the bunker chain is slowly drawn
back carrying about 1 st (0.9 t) of coal per yard of chain. The bunker is
later discharged by reversing the process. See also:underground bunker
Nelson
A large form of inclined canvas table in which the pulp is first
classified, then distributed along the upper edge of the table. The
concentrates are caught in the warp of the canvas; after this is full,
treatment must be stopped while the concentrates are swept or sluiced off.
Liddell
A paddlelike implement used to shut off the flow of metal from a mold and
divert it to other molds. Standard, 2
A pillar consisting of tightly rammed material enclosed in walls of stone,
built on each side of the gate road. See also:double packing
Nelson
N. of Eng. A continuous coal face served by gateways (in Durham about 12
yd or 11 m apart). A small group works in each gateway down which the coal
is removed by tubs. Trist