The tiering truck (fig. 6-12) is an electric-powered
forklift truck of the straddle-arm design. The location of
the forks on the tiering truck are between two outriggers
or straddle arms. The straddle arms extend forward in a
plane at floor level parallel to that of the forks to straddle
the pallet load. Because the straddle arms have contact
with the floor, they support the elevated load and do not
require a counterweight. The overall weight of the
tiering truck is less than that of a conventional forklift
truck of the same rated capacity. The tiering truck is
more maneuverable than the standard forklift truck and
it can operate in 6-foot aisles. The standard tiering truck
for the military services is the electric-powered type. It
has a load capacity of 3,000 pounds and a lifting height
of 100 to 130 inches.
The pallet sling (fig. 6-13) is used for overhead
lifting of palletized loads by a crane or ships boom.
Normally, a cable is used for the sling, but a line or chain
may be used, depending on the weight of material to be
Slings have rigid horizontal supports at the base,
usually made of steel bars or pipes. The horizontal
support must be strong enough to distribute the load
across the entire length.
Some slings have movable spreader bars at the top
to prevent crushing the load while it is being lifted.
HOISTS, PULLEYS, AND DOLLIES
Various types of hoists, pulleys, and dollies are
available ashore and afloat for moving equipment and
supplies. You should familiarize yourself with this
equipment and its purpose so that as various situations
arise, you can select the proper piece of equipment.
Chain hoists or chain falls provide a convenient and
efficient method for hoisting loads by hand. The
advantages of chain hoists are that one person can raise
a load of several tons. Also, without securing the load,
it can remain stationary. One person can carry and
operate the manually operated chain hoists (fig. 6-14,
view A). They are particularly useful in loading and
unloading cargo trucks. They also are convenient for
working in small storerooms aboard ship when other
mechanized equipment is not available.
Figure 6-15.-Blocks and tackles.
Some larger storerooms have electrically operated
hoists that move along overhead tracks (fig. 6-14, view
B). Electric hoists lift their loads by either chain or cable.
Other models are pneumatic or air hoists that operate by
compressed air. These hoists have the advantages of
speed and ease of operation.
Block and Tackle
A block and tackle is the arrangement of one or more
pulleys with rope or cable for pulling or hoisting large
or heavy objects. The block and tackle (also called tackle
or pulley) is used in the same situations as the chain
hoist, except for smaller loads. Figure 6-15 shows the
different types of blocks and tackles. It also provides the
formula for figuring the amount of power needed to
move the weight of the load.
The dolly or dolly truck is a frame mounted on
wheels or rollers. Dolly trucks are used for moving or