In hoisting with slings, spreader bars are used to
prevent crushing and damaging the load. Spreader
bars are short bars, or pipes, with eyes fastened to each
end. By setting spreader bars in the sling legs above
the top of the load (fig. 6-31), you change the angle of
the sling leg and avoid crushing the load, particularly
in the upper portion.
Spreader bars are also used in lifting long or
oversized objects to control the sling angle, as shown
in figure 6-32. When spreader bars are used, make sure
you do not overload the end connection. A spreader
bar has a rated capacity that is the same as hooks and
shackles. A good rule of thumb is the thickness of the
spreaders end connection should be the same as the
thickness of the shackle pin.
Cargo pallets coupled with slings are an immense
advantage on jobs that involve moving a lot of small
items (fig. 6-33). Spreader bars can be used often to
avoid damaging the pallet and the load. The pallet
supplies a small platform on which a number of items
can be placed and then moved as a whole instead of
piece by piece. Palletizing is clearly easier and faster
than moving each item by itself.
Commonly, packages of the same size are
palletized together, and when shipped, remain on the
pallet until they are used up. You may not have the
luxury of having excess pallets at your job site;
Figure 6-31.Using spreader bars.
Figure 6-32.Spreader bar used with an oversized load.
Figure 6-33.Cargo pallet.
however, you need to have several to work efficiently.
One can be loaded as the prior loaded one is being
lifted. After each pallet is unloaded, the hoist will
return for reloading. With two pallets, you are able to
maintain a steady flow of material. One set of slings
will be able to handle any number of pallets.
To be able to place cribbing, skids, and rollers, you
need to be able lift a load a short distance. Jacks are
designed and built for this purpose. Jacks are also used
for precise placement of heavy loads, such as beams,
or for raising and lowering heavy loads a short