A tunnel constructed for disposing of mine water. Long tunnels have been
driven in some mining districts for the purpose of passing under the lower
workings of several mines and tapping the water for the entire group.
Where topographic features permit, a drain tunnel--more properly called an
adit--may also be driven to serve a single mine. The chief advantages of a
drain tunnel lie in saving the cost of pumping and eliminating the danger
of the mine being flooded through failure of the pumps. Also called
drainage tunnel. CF:drainage
A new cutter loader devised by Maynard Davies and developed at the Central
Engineering Establishment of the National Coal Board of Great Britain. A
shearer drum is carried on a vertical shaft in contrast to the horizontal
shaft in the Anderson shearer. Nelson
Vertical-current separator (obsolete) used to separate shale from coal.
Pryor, 3
Warping in the beds overlying a reef, as a result of differential
compaction.
a. S. Staff. The quantity of coal hoisted in a given time.
b. The pressure required to supply air to a furnace and to remove the flue
gases from the furnaces. Natural draft is produced by a chimney, while
artificial draft is produced by fans and is controlled by the speed of the
fans, by variation in the pitch of the fan blades, or by dampers.
Francis, 2
A trigonal mineral, 3[NaMg3 Al6 (OH,F)4 (BO3 )
3 Si6 O18 ] ; tourmaline group; forms series with
schorl and with elbaite; in triangular or hexagonal prisms; pyroelectric
and piezoelectric; in metamorphic and metasomatic lime-rich rocks; slices
are used to measure transient blast pressures.
a. The horizontal distance on the surface ahead of an underground coal
face over which the rocks are influenced by subsidence.
See also:angle of draw
b. The break in strata from a coal face to the surface; the angle between
this break and the vertical. Mason
c. To remove broken ore by gravity from stopes, chambers, or ore bins by
aid of chutes or conveyors. Pryor, 3
d. To mine out or rob the pillars in a mine, after the rooms are worked
out.
e. To pull bit-bank metal toward a diamond by peening and calking when
handsetting a diamond bit. Long
f. See:pull
g. The effect of creep upon the pillars of a mine. Fay
h. To raise ore, coal, rock, etc., to the surface; to hoist. Fay
i. To transport by hand; to put; to tram. Mason
j. To allow ore to run from working places and stopes through a chute into
trucks. CTD
k. To withdraw timber props from overhanging coal, so that it falls ready
for collection. CTD
A measure of the workability of a metal subject to a drawing process. This
term is usually expressed to indicate a metal's ability to be deep-drawn.
ASM, 1
Remove explosives. Zern
a. A bead or offset used for controlling metal flow. ASM, 1
b. Riblike projections on draw rings or hold-down surfaces for controlling
metal flow. ASM, 1
a. In underground blasting, cut holes that are inclined upward.
Lewis
b. In rock blasting, bottom cut. Pryor, 3
c. See:drag cut
a. Scot. A man or boy who takes ore or rock from the working face to the
shaft, or terminus of the horse or haulage road. One who pushes trams or
drives a horse underground. Fay
b. Derb. A man who hoists ore or rock by means of a windlass, or
otherwise, from a shaft. Fay
c. Putter; trammer; wagoner; a person who moves tubs either manually or
with a machine. Mason
Removal of the load from a furnace for a short time, prior to the
completion of burning, to equalize heating of all areas. Also called draw
burning. Bryant
The term includes drawbars, chains, shackles, detaching hooks, etc., used
in haulage, winding, and hoisting. Nelson
An aperture in a battery through which the coal or ore is drawn.
Fay
a. Recovering the timbers, chocks, etc., from the goaves. This work is
commonly performed with the use of the dog and chain. Fay
b. Knocking away the sprags from beneath the coal after holing.
Fay
c. Raising coal through a shaft or slope. Fay
d. In hydraulic mining, throwing the water beyond the dirt to be removed
and causing it to flow toward the giant. CF:goosing
e. Removing or pulling out the crown bars in a tunnel. Stauffer
f. The movement of tubs. Pryor, 3
g. Forming recessed parts by forcing the plastic flow of metal in dies.
ASM, 1
h. Reducing the cross section of wire or tubing by pulling it through a
die. ASM, 1
i. A misnomer for tempering. ASM, 1
j. Continuous forming of sheet, tube or fibrous glass from molten glass.
Van Vlack
Removing the last of the coal from an entry. Fay
Reduction of cross section of steel by forging. Pryor, 3
The lowest lift of a Cornish pump, or that lift in which the water rises
by suction (atmospheric pressure to the point where it is forced upward by
the plunger). Also called drawlift.
When a winding rope, from the effects of wear and tear, has become less in
diameter or in thickness from that cause, it is said to be "drawing
small." Fay
The removal of timbers and supports from abandoned or worked out mine
areas. This work is highly specialized and should be attempted only by the
most experienced persons. Generally, timbers are pulled by a timber puller
that permits the operator to be under a safe roof while doing this work.
In some cases, where so much weight is resting on the timber that it
cannot be removed safely, it must be shot out by use of explosives, and
the roof allowed to fall. See also:sylvester
Kentucky