A grader,
also commonly
referred to as
a road grader, a blade, a maintainer, or a motor
grader, is
a construction machine with a long blade used to create a
flat surface.
Typical
models have three axles, with
the engine and cab situated
above the rear axles at one end of the vehicle and a third axle at the
front
end of the vehicle, with the blade in between. In certain
countries,
for example in Finland, almost every grader is equipped with a
second
blade that is placed in front of the front axle. Some construction
personnel
refer to the entire machine as "the blade."
Video: Grader at work
In civil
engineering, the grader's
purpose is to "finish grade" (refine, set precisely) the "rough
grading" performed by heavy equipment or engineering vehicles such
as scrapers and bulldozers.
Graders
can produce inclined
surfaces, to
give cant (camber) to roads. In some countries they
are used
to
produce drainage ditches with shallow V-shaped cross-sections on either
side of
highways.
