Preparation for Transport

TM 55-2320-279-14

WARNING

5-8. Preparation for Transport

Loads with a high center of gravity have a

Preparation of the HEMTTs for semitrailer trans-

tendency to overturn at normal highway

port includes the following procedures:

speed. Drivers should exercise extreme

a. All basic issue items (BII) should be secured to

caution when entering curves or inclined

preclude damage en route.

road conditions. Potholes or uneven pave-

b. Spare tire should be removed and secured on

ment will also increase overturning possi-

the vehicle.

bilities.

c. Each vehicle should be reduced to a cab

The National Network of Highways (NNH) con-

height of 101 inches, except for the M978 supports,

which are on top of the fuel-servicing tank and are

sists of the US Interstate System and designated

107.7 inches.

portions of highways in the Federal-Aid Primary

(FAP) system. For the NNH, the length limitations

d. Communication antennas should be removed

and stowed.

do not include the total length of the tractor and

semitrailer. However, the length limit without

e. Personnel should not be allowed on semi-

permit for semitrailers is 48 feet (14.63 m). The

trailer during loading or unloading operations.

width limit for the NNH is 102 inches (2.59 m).

5-9. Loading and Tiedown on Semitrailer

On highways not included in the NNH, the Ameri-

a. The HEMTTs may be driven on the semi-

can Association of State Highway and Transporta-

trailer over suitable ramps or a loading deck. They

tion Officials (AASHTO) policy limitation without

may also be lifted and placed on the semitrailer by

permits for length of truck-tractor and semitrailer

a crane of adequate capacity.

is 60 feet (18.29 m). Width and height limitations

b. The bill of materials for blocking and tiedown

are 96 inches (2.44 m) and 13 feet 6 inches (4.12 m),

of the HEMTT on a semitrailer is shown in table

respectively.

5-1. A blocking and tiedown diagram compatible

The axle load limitation without permits for a US

with standard loading practices that will offer ade-

highway system, as published by AASHTO, is

quate restraint is provided in figure 5-1. Data con-

20,000 pounds (9072 kg) per single axle and 34,000

cerning application of materials are provided in

pounds (15442 kg) per tandem axle.

table 5-2.

5-2