2.22.
SPECIAL RAIL CARS
Some of the Army's highly refined weapons systems, such as
missiles, rockets, and nuclear warheads, pose special transportation
problems because of their size and sensitivity.
While in transit,
these weapons may be damaged by handling, environment, and the
conveyance itself; therefore, special care must be taken in moving
and protecting them.
One of the more recently developed railway
cars, designed for both piggyback and container service, is equipped
with a shock-absorbing mechanism that provides a high degree of
protection for the equipment and lading.
Shown in figure 2.14, it
has three basic elements: a container, a trailer chassis, and the
piggyback rail car itself. The following subparagraphs discuss this
equipment.
Figure 2.14.
Piggyback Rail Service Equipment.
a. Container.
Specifically designed and built to operate
interchangeably between road, rail, and ship, the container is the
key item in containerization transportation. It can be used in lift-
on-lift-off or roll-on-roll-off service. The container is built with
lifting eyes and stacking castings on all four corners and is
engineered to withstand the stresses of lift-on-lift-off operations
at ports, rail terminals, or loading docks.
The corner post
construction permits stacking of fully loaded containers.
These
features of design and construction are particularly desirable in
ship operation where a crane is the one practical means of loading
and unloading containers.
Some containers have fork pockets that
Pulling a
container on or off the rail car is done with a power-operated winch
that provides the power to draw the container on or off the car. The
container is locked to the rail car by the same kind of tiedown
clamps used to secure ordinary truck trailers.
b. Trailer chassis.
Designed and built to accommodate the
container, the trailer chassis has devices that lock and unlock the
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