TM 9-2330-359-14&P
2-15. TOWING INSTRUCTIONS.
WARNING
l Before moving semitrailer, ensure that all loose equipment is properly stowed and
that nothing will drag on ground. If semitrailer is loaded, ensure that load is properly
secured. Failure to follow this warning may result in injury to personnel or damage to
equipment.
l DO NOT tow semitrailer at speeds exceeding the following. Failure to follow this
warning may result In injury to personnel or damage to equipment.
Highway
55 mi/h (88 km/h)
Dirt/Gravel 20 mi/h (32 km/h)
Off-road
10 mi/h (16 km/h)
a. Perform all During (D) PMCS in Table 2-1 while operating the semitrailer.
b. When towing the semitrailer, overall length of the unit must be kept in mind when passing other vehicles
and when turning.
c. Turning and backing operations will be affected because the towing vehicle and semitrailer are a hinged
unit. When backing have assistant direct you. Adjust rearview mirrors before backing. When backing, rear of
semitrailer will move in opposite direction from towing vehicle’s front wheels. If wheels are turned to the right,
semitrailer will go Ieft. If wheels are turned left, semitrailer will go right.
d. Always tow the semitrailer at safe speeds and note any driving irregularities.
NOTE
Ensure that chock block chains are disconnected from semitrailer before chocking
wheels.
e. When parking for extended periods, set parking brakes on both towing vehicle and semitrailer. Turn off
towing vehicle engine before leaving cab. Chock semitrailer wheels.
f. if the towing vehicle and semitrailer are parked on a hill, chock wheels.
g. Refer to FM 21-305 for further information on proper driving practices.
2-16. CAGING AND UNCAGING SPRING BRAKES (M872 AND M872A3).
a. Caging Spring Brakes.
WARNING
Chock wheels to prevent semitrailer from moving when brakes are released (caged).
Failure to follow this warning may result in serious injury or death.
NOTE
In the event of air system pressure loss, failsafe units on center axle will automatically
apply brakes. If semitrailer must be moved and there is not enough air system pressure
to compress spring in spring brake chambers to release brakes, you will have to do this
manually.
(1) Chock semitrailer wheels.
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