In tunnel blasting, holes that parallel the tunnel alignment drilled
between the cut and the perimeter holes.
Lanc. Opening leading from a working face to the surface. Hess
In driving a tunnel, a hole blasted after the bottom cut. Pryor, 3
a. N. Staff. A short leading stall, worked at right angles to, and forming
the face of, the main level.
b. A wide heading or level.
c. Eng. Taking ore from the face or head of a drift.
d. In drift mining, breaking down the gravel underground, and retreating
towards the crosscut from which the drifts were driven.
von Bernewitz
e. Cumb. A place driven to open out a longwall face. SMRB
A machine used for undercutting coal in which the main frame and carriage
are held stationary by roof jacks while the cutter frame advances into the
kerf during the cutting operation. Since cuts do not exceed 44 in (1.1 m)
along the face, it is necessary to relocate the machine several times
before the entire face can be cut. Jones, 1
A slightly curved iron plate fastened to the end of a coal auger to enable
a miner to press the auger forward using body pressure.
A method of stoping employed on veins where the dip is not sufficient for
the broken ore to be removed by gravity. The ore remains close to the
working face and must be loaded into cars at that point.
See also:overhand stoping
A leaning brace from the floor of an excavation to a wall support.
Nichols, 1
A wall designed to withstand the force of a natural bank of earth, such as
of timber used to support the face of a tunnel. Syn:jamb wall
AGI
Alternate expansion and contraction of air in breaks that allows fresh
oxygen to be drawn in and oxidation to proceed. Sinclair, 1
a. A filter self-rescuer (FSR) is a respiratory protective device that
filters ambient air of carbon monoxide, converting it to carbon dioxide.
Exhaled air is vented back to ambient. Also called a gas mask. Duration of
protection is limited, usually, by water contamination of the chemical
bed. Used for escape from underground mines in the event of a fire or
explosion. Requirement specified in 30 CFR 75.1714-2(e)(2). Apparatus must
be certified as providing at least one hour of respiratory protection.
Apparatus available in the United States are the Draeger 910 and the MSA
W-65, both certified for one hour.
b. A self-contained self-rescuer (SCSR) is a respiratory protective device
that provides breathing gas independent of the ambient atmosphere,
containing its own oxygen source. Also called an oxygen self-rescuer. Air
is exchanged between the user's lungs and a breathing bag. Oxygen consumed
by the user is replaced by the apparatus from its oxygen source, stored
either in chemical or compressed form. Carbon dioxide produced by the user
is removed by a chemical absorbent in the apparatus breathing circuit.
Duration of protection is determined by both quantity of stored oxygen and
carbon dioxide absorption capacity. SCSRs differ from rescue breathing
apparatus in that the breathing bag is not protected by a rigid cover in
order to reduce size and weight. Used for escape from underground mines in
the event of a fire or explosion. Requirement specified in 30 CFR 75.1714.
Apparatus must be certified as providing at least one hour of respiratory
protection. Apparatus available in the United States are the CSE SR-100,
the Draeger OXY K plus, the MSA Portal-Pack, the Ocenco EBA 6.5, all
certified for one hour.
c. A rescue breathing apparatus (RBA) is a respiratory protective device
that provides breathing gas independent of the ambient atmosphere,
containing its own oxygen source. Air is exchanged between the user's
lungs and a breathing bag. Oxygen consumed by the user is replaced by the
apparatus from its oxygen source, stored in compressed form in most
apparatus. Carbon dioxide produced by the user is removed by a chemical
absorbent in the apparatus breathing circuit. Duration of protection is
determined by both quantity of stored oxygen and carbon dioxide absorption
capacity. RBAs differ from self-contained self-rescuers in that the
breathing bag is protected by a rigid cover in order to prevent accidental
puncture or tear. Used for entry into underground mines after a fire or
explosion in order to reestablish the ventilation system, rescue trapped
miners, and put out fires. Requirement specified in 30 CFR 49.1. Apparatus
must be certified as providing at least two hours of respiratory
protection. Apparatus available in the United States are the Biomarine
BioPak 240 and the Draeger BG-174A, both certified for four hours.
a. A cave in which air is alternately blown out and sucked in at the
entrance. Schieferdecker
b. A narrow part in a passage through which air blows.
Schieferdecker
A coarse-grained clastic rock, composed of angular broken rock fragments
held together by a mineral cement or in a fine-grained matrix; it differs
from conglomerate in that the fragments have sharp edges and unworn
corners. Breccia may originate as a result of talus accumulation,
explosive igneous processes, collapse of rock material, or faulting.
Etymol: Italian, broken stones, rubble. Syn:rubblerock
brecciated. CF:conglomerate; loose ground. AGI
Converted into, characterized by, or resembling a breccia; esp. said of a
rock structure marked by an accumulation of angular fragments, or of an
ore texture showing mineral fragments without notable rounding.
AGI
An orthorhombic mineral, Ca7 Mg(SiO4 )4 ;
pseudohexagonal. CF:larnite
Mid. Drawing loaded trams downhill underground. Syn:britching
See:breeze
a. Coke of small size; the undersize remaining after separating the
smallest size of graded coke. Also spelled breese. BS, 3
b. The dust from coke or coal. Mersereau, 2
c. An indefinite term that usually means clinker, but that may refer to
coke breeze. Taylor
d. Scot. Fine or slack coal.
A concrete made of 3 parts coke breeze, 1 part sand, and 1 part portland
cement. It has poor fire-resisting qualities but it is cheap and nails can
be driven into it. Nelson
a. An oven for the manufacture of small coke. Fay
b. A furnace designed to consume breeze or coal dust. Fay
Nickel antimonide, NiSb. See also:niccolite