TM 9-2330-246-14
Section IV OPERATION UNDER UNUSUAL CONDITIONS
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Fording . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Operation in Extreme Cold . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Operation in Extreme Heat . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Operation in High Humidity, Heavy Rain, and Saltwater Areas
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Operation in Mud . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Operation in Sandy or Dusty Areas . . . . . . . . . . . . . . . . . . . . . .
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Operation in Snow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-21. GENERAL.
a. This section contains instructions for safely operating the semitrailers under unusual conditions. In
addition to normal preventive maintenance service, speciai care must be taken to keep the semitrailers operational in
extreme temperatures and humidity.
b. Refer to FM 55-30 for information on driver selection, training, and supervision.
c. Refer to FM 21-305 for information on special driving instructions for operating wheeled vehicles under
unusual conditions.
2-22. OPERATION IN EXTREME COLD.
a. Special care must be taken when operating semitrailers in extreme cold weather. Refer to FM 9-207 for
information on operation in cold weather.
b. Refer to Chapter 3, Section i for proper lubrication during extreme cold weather.
c. Generally, extreme cold causes lubricants to thicken or freeze and various semitrailer materials to
become hard and brittle, and easily damaged or broken. Extreme cold weather also can cause insulation on electrical
wire to crack, causing short circuits. The operator must be alert to effects of extreme cold on semitrailers.
d. When parking for any period of time in temperatures below 0F (-18C), park in a sheltered area out of
the wind and clean off any buildup of ice or snow. Place a footing of planks or brush under tires to prevent them from
freezing to the ground. Ensure that tires are properly inflated (para 1-10). Underinflated tires will freeze, resulting in flat
spots.
e. Use caution when placing semitrailer in motion after a shutdown. Thickened lubricants may cause
component failure. Free frozen brakeshoes, or tires frozen to ground, with care.
2-23. OPERATION IN EXTREME HEAT.
a. Refer to Chapter 3, Section i for proper lubrication during extreme heat.
b. Do not park semitrailer in sunlight for long periods of time. Heat and sunlight shorten tire life.
CAUTION
DO NOT use gasoline or dry cleaning solvent to remove oil or grease spots from
tarpaulin. Use only water and a scrub brush. Failure to follow this caution will damage
tarpaulin.
c. Cover inactive semitrailer with tarpaulins if no other shelter is available. Tarpaulins are subject to
deterioration from mildew and attacks by insects or animals. Shake out and air tarpaulins for several hours weekly.
Clean mildewed tarpaulin with a dry scrub brush. DO NOT clean with water until mildew is removed. If mildew is found,
examine tapaulin to determine if it is rotted or weakened. Replace tarpaulin if damaged. If tarpaulin is not damaged,
treat as outlined in FM 10-16.
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