OPERATION UNDER UNUSUAL CONDITIONS
This WP contains instructions for safety operating the semitrailer under unusual conditions. In addition to
performing normal preventive maintenance service, you must take special care to keep the semitrailer
operational in conditions of extreme temperatures and humidity.
For information on driver selection, training, and supervision, refer to FM 55-30.
For more information on special driving instructions for operating wheeled vehicles under unusual
conditions, refer to FM 21-305.
OPERATION IN EXTREME COLD
Sudden changes in temperature may cause semitrailer
to develop leaks at fittings and connectors. Use caution
and pay special attention to these areas. If something is
broken or worn out, report it to Organizational maintenance.
Corrective action must be performed before resuming any
operations. Failure to follow this warning may result in injury
Take special care when operating semitrailer in extremely cold weather. Refer to FM 9-207 for
information on operation in cold weather.
In addition to performing all normal PMCS, take special care in regard to cleaning and lubrication
when extreme in temperature, humidity, and terrain conditions are present or anticipated. Proper
cleaning, lubrication, storage, and handling ensures proper operation and function and guards
against excessive wear. Refer to WP 0035 00 for proper lubrication during extremely cold weather.
Generally, extreme cold causes lubricants to thicken or freeze and various semitrailer construction
materials to become hard and brittle and easily damaged or broken.
Take care when handling cables. Extremely cold weather can cause insulation material on
electrical wire to crack, resulting in short circuits.
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. Make sure the tires are properly inflated 95 psi
(655 kPa). Under inflated tires will freeze, resulting in flat spots.
Use caution when placing semitrailer in motion after a shutdown. Thickened lubricants may cause
component failure. Free frozen brake shoes or tire frozen to the ground with care.
OPERATION IN EXTREME HEAT
Refer to WP 0035 00 for proper lubrication during high heat conditions.
Do not park semitrailer in sunlight for long periods of time. Heat and sunlight shorten tire life.
OPERATION UNDER UNUSUAL CONDITIONS--Continued