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Back Figure 1-8.—Wire-rope fittings. | Up Construction Electrician Basic - Electricity handbook for electricians | Next Fiber-Line and Wire-Rope Slings |
the diameter, 6 x D = DISTANCE BETWEEN CLIPS.
Here, as in determining the number of clips, if the
answer contains a fraction, use the next whole number.
You should inspect and tighten wire-rope clips at
regular intervals. Also, after comparatively long use,
remove the clips and examine the wire rope for broken
wires. If any are present, remove the damaged part and
make a new attachment.
Knots
Although wire-rope fittings are stronger and safer
and make wire rope last longer, you may have to use
knots in emergencies. Use knots secured with clips (fig.
1-7). Figure 1-7 also shows the proper way to join two
wire ropes.
Fittings
fittings are attached to the ends of wire rope so that
the wire rope can be easily connected to other wire
ropes, chains, pad eyes, or heavy equipment. Figure 1-8
shows some standard fittings. The type of fitting used
depends on the job. For instance, to hoist a bundle of
conduit from ground level, use two wire rope slings
made using a thimble in the wire rope and then attaching
a shackle to the thimble. A thimble in an eye splice
reduces abrasive wear on the wire rope (fig. 1-8, view
2).
Hooks and Shackles
Hooks and shackles (fig. 1-9) provide a useful
means of hauling the lifting loads without tying directly
to the object with a line, wire rope, or chain. They can
be attached to wire rope, fiber line, blocks, or chains.
Shackles should be used for loads too heavy for hooks to
handle.
When hooks fail because of overloading, they
usually straighten out and lose or drop their load. When
a hook has been bent by overloading, do NOT straighten
it and put it back into service.Cut it in half with a cutting
torch and discard it.
Hooks should be given a visual inspection at the
beginning of each workday and before lifting a full-
rated load. If you are not sure whether a hook is strong
enough to lift the load, use a shackle.
You should use hooks that close and lock where
there is danger of catching on an obstruction. This
applies particularly to hoisting buckets, or cages, and
especially in shaft work. Hooks and rings used with
chain should have about the same strength as the chain.
SLINGS
Slings are widely used in the moving and hoisting
of heavy loads. You can obtain some types of slings
already made up, but frequently you may have to make
Figure 1-9.Hooks and shackles.
1-9
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