disc and drums, creating heat. Brakes are designed to
withstand intense heat; however, brakes can fail from
excessive heat if you try to slow down from a high speed
too many times too quickly. Brakes fade (have less
stopping power) when they get hot and may not slow
the vehicle.
The correct way to use your brakes for long
downhill grades is to go slow enough that fairly light use
of the brakes prevents your speed from increasing.
When you go slow, the brakes can cool down.
Some operators think that backing off on the brakes
from time to time (fanning) allows them to cool enough
to prevent overheating. Tests have proven this is not
true. Brake drums cool slowly, so the amount of cooling
between applications is not enough to prevent over-
heating. This type of braking requires heavier brake
pressure than steady application does. The heavier
pressure used on the brakes builds up more heat than the
light continuous pressure does; therefore, select the right
gear, go slow, and maintain a lighter, steadier use of the
brakes.
Escape Ramps
Escape ramps are constructed on most steep
mountain grades. They are used to stop runaway
vehicles safely without injury to drivers or passengers.
Escape ramps use along bed of loose soft material, such
as pea gravel or sand, to slow a runaway vehicle.
Sometimes, they are used in combination with an
upgrade.
VEHICLE RECOVERY
Recovery is a major operation. During any recovery
operation, always use a proven procedure. A haphazard
approach to a recovery problem or the use of a
trial-and-error method can be a costly mistake. Such a
mistake can deadline the disabled vehicle longer than
necessary, cost valuable time, damage equipment, and
injure personnel. Self-recovery of vehicles, recovery
with wreckers, and recovery with like-vehicles are
discussed in this section.
WRECKERS
Recovery, using wrecker trucks, should be
performed by trained recovery personnel of Alfa
company or the transportation division. An under-
standing of the ability of the vehicle to winch, lift, and
tow is very important. For in-depth information, refer to
the operators manual that relates to the operation of
specific equipment and their specific abilities.
Mired Truck
The recovery of a mired truck using a wrecker truck
is not always an easy task because it involves the
resistance of the load, the approach to the load, and the
distance between the wrecker and the mired vehicle. Use
a direct pull if the resistance created by the mired vehicle
is less than the winch capacity of the wrecker.
CAUTION
Do not hook the winch cable around the
bumper on a vehicle. Wrapping the tow cable
around the bumper of a mired vehicle will result
in a bent bumper.
An example of a simple winching operation is
shown in figure 5-6. Some winching operations are
more difficult. The mired truck may have a resistance
greater than the winch capacity of the wrecker. Also, the
wrecker may not be able to align itself with the truck
due to terrain. If so, use a 2:1 mechanical advantage and
a change of direction pull, as shown in figure 5-7.
Nosed Truck
The recovery of a nosed truck using a wrecker truck
may require only a towing operation. Some situations
may require all three of the capabilities (winching,
Figure 5-6.-Simple winch operation (direct pull).
5-8