Mack CSM 2010, Руководство оператора

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106 OPERATION
Descending a Grade
DANGER
The MACK PowerLeash™ Engine
Brake assists you in establishing faster
downhill descent speeds than in a similarly
configured and loaded vehicle without
an engine brake; nevertheless, even with
an engine brake, there are limits to the
maximum vehicle speed at which you can
travel on downhill grades and still keep
your vehicle safely under control. Always
approach these situations with caution,
and gain the experience necessary for each
grade and driving condition to determine
the appropriate downhill descent speed.
For a certain vehicle and load condition, a "control speed" may be established for a given
descent. The control speed is the vehicle speed at which the retarding forces of air drag,
rolling resistance and engine brake power are equally balanced by the natural force of
gravity that causes the vehicle to accelerate down the hill, resulting in a steady, controlled
vehicle speed. The additional vehicle slowing power offered by the MACK PowerLeash™
Engine Brake allows the driver to descend the hill in a higher gear than normal (at a faster
control speed), without overspeeding the engine.
For example, consider that you are descending a grade with a specific vehicle and an
assumed total vehicle weight. You will find that without an engine brake, you must descend
this grade in third gear to maintain a steady 16 kph (10 mph)at 2,000 engine rpm, without
the need to apply the service brakes.
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