TAG LINE A line from a crane boom to a clamshell
bucket that holds the bucket from spinning out of
position.
TAMP Pound or press soil to compact it.
TERRACE A ridge, a ridge and hollow, or a flat bench
built along a ground contour.
TERRAIN Ground surface.
TOE The projection of the bottom of a face beyond the
top.
TOOTH ADAPTER Main part of bucket or dipper to
which a removable tooth is fastened.
TOPOGRAPHIC MAP A map, indicating surface
elevation and slope.
TOPSOIL The topmost layer of soil, usually refers to
soil containing humus that is capable of supporting
good plant growth.
TORQUE The twisting force exerted by or on a shaft
(without reference to the speed of the shaft).
TRACK A crawler track.
TRACK CARRIER ROLLERS Rolling elements
in/on a track frame that support and guide the upper
track shoes or chain.
TRACK SHOES The members of the track assembly
that distribute the load to the supporting surface.
TRACTION The total amount of driving push of a
vehicle on a given surface.
TRENCH A ditch.
TRUNNION (Walking beam or bar) (1) An
oscillating bar that allows changes in angle between
a unit fastened to its center and another attached to
both ends. (2) A heavy horizontal hinge.
UNDERCARRIAGE The undercarriage is an
assembly that supports the upper structure of the
crane. It consists of an undercarriage frame, a swing
bearing, or hook and load rollers, travel mechanism,
and steering mechanism. The undercarriage may be
either a crawler or wheeled type.
VISCOSITY The resistance of a fluid to flow. A liquid
with a high viscosity rating will resist flow more
readily than will a liquid with a low viscosity. The
Society of Automotive Engineers (S.A.E.) has
developed a series of viscosity numbers for
indicating viscosities of lubricating oils.
VOIDS Empty spaces in a compacted mix, surrounded
by asphalt-coated particles.
VOLTS The electromotive force that will cause a
current of 1 ampere to flow through a resistance of
1 ohm.
WATERLOGGED Saturated with water. If conditions
are too wet, you will be unable to work construction
equipment.
WATERSHED Area that drains into or pasta point.
WATER TABLE The surface of underground,
gravity-controlled water.
WHEEL AND AXLE ARRANGEMENT The
wheeled undercarriages.
WINCH A drum that can be rotated so as to exert a
strong pull while winding in a line.
WINDROW A ridge of loose dirt.
WING WALL A wall that guides a stream into a bridge
opening or culvert barrel.
WORKING CYCLE A complete set of operations. In
an excavator, it usually includes loading, moving,
dumping, and returning to the loading point.
AI-8