The right to cut timber on the public domain for commercial use.
In anthracite and bituminous coal mining, a laborer who pulls out and
recovers timbers and props in working places from which all coal has been
mined. Also called prop drawer; timber puller. DOT
A timber frame to support the roof, sides, and sometimes the floor of mine
roadways or shafts. For a mine roadway, the simplest timber set consists
of a crossbar, cap, or collar supported on two upright posts or arms with
round or board lagging. Such a set will resist roof pressure and moderate
side pressure and is erected at intervals of from 2 to 6 ft (0.6 to 1.8
m). The timbers are about 5 to 10 in (12.7 to 25.4 cm) in diameter. In
South Wales, such a timber set is known as double timber.
See also:timbering; bar timbering; two-piece set; three-piece set;
four-piece set. Nelson
A strong carriage of low height for transporting timber from the surface
stockyard to underground workings. It consists of a timber or steel base,
mounted on wheels, with U-shaped arms in which the timber is lashed with
chains. See also:bogie
Any truck or car used for hauling timbers inside a mine. In conveyor work,
it is applied to the small truck mounted on wheels that is designed to run
in the panline of a shaker conveyor for the purpose of carrying timber and
other materials to the face. Jones, 1
The coordination and analysis of the data provided by time study and
motion study. Nelson
In seismic exploration, the time required for the seismic impulse to
travel from the charge in the shothole to the surface of the Earth.
Syn:uphole time
An indication on a seismic record showing the instant of detonation of a
shot or charge. CF:time signal
time mark. AGI
Correlation of rocks in one area with those of another area on basis of
time equivalence or contemporaneity of origin.
Relay that does not operate until a predetermined time has elapsed. The
time ratings are usually adjustable, but some time-delay relays have the
time rating built into them. Coal Age, 3
A graphical expression of the functional relation between the velocity
function and the times observed in the seismic method of geophysical
exploration. It permits time increments to be converted to corresponding
depths. Syn:time-depth curve
See:time-depth chart
In refraction seismic computations, a graph, usually with arrival times of
distinctive seismic signals plotted as ordinates and with distances along
the surface of the Earth plotted as abscissas. In earthquake studies, the
times of arrival of seismic waves at recording stations may be known, but
the time of initiation of the waves may be unknown. As data are
accumulated from different recording stations, a time-distance graph may
be constructed. If it is possible to extrapolate this graph to the origin
on the time and distance coordinates, it becomes a travel-time curve.
AGI
In refraction seismic computations, a plot of the arrival times of
refracted events against the shot-point-to-detector distance. The
reciprocal slopes of the plotted segments are the refraction velocities
for the refracting bed. AGI
In the reflection seismic methods applied to dipping reflectors, the
travel time curves may not be straight lines; i.e., the apparent velocity
observed varies with the spread from shot point to detectors. The time
gradient is the reciprocal of the apparent velocity. In seismic
prospecting, also the rate of change of travel time with depth.
AGI
a. In refraction seismic interpretation, where arrival times are plotted
against shot-detector distances, if some of the paths from shot point to
detector include a low-speed bed, the corresponding arrival times will be
abnormally long, and the departure from normal travel time is called a
time lag. Also, in seismic prospecting, time delays in arrivals due to
phase shifts in filtering, to shot-hole fatigue, etc. AGI
b. A delay in the arrival time of seismic energy from the time expected.
Time lags may be produced by an abnormal low-velocity layer, phase shifts
in filtering, or other factors. AGI
In a method of interpretation of refraction seismic records where the
arrival times are plotted against shot-detector distances, if some of the
paths from shot point to detector include a high-speed segment, the
corresponding travel times will not fall on a smooth curve. The departure
in this case from the curve is called a time lead, and it is proportional
to the horizontal extent of the high-speed segment. Used in salt-dome
exploration. AGI
a. See:time break
b. Mark corresponding to a particular time (e.g., hour, minute, and second
time marks) on a seismic recording.
Lines on a seismogram that mark increments of time. Schieferdecker