When an eye is made in a wire rope, a metal fitting,
called a thimble, is usually placed in the eye, as shown
in figure 13-23. The thimble protects the eye against
wear. Wire rope eyes with thimbles and wire rope clips
can hold approximately 80 percent of the wire rope
After the eye made with clips has been strained, the
nuts on the clips must be retightened. Checks should be
made now and then for tightness or damage to the rope
caused by the clips.
Swaging makes an efficient and permanent
attachment for wire rope, as shown in figure 13-25. A
swaged connection is made by compressing a steel
sleeve over the rope by using a hydraulic press. When
the connection is made correctly, it provides
100-percent capacity of the wire rope.
Careful inspection of the wires leading into these
connections are important because of the pressure put
upon the wires in this section. If one broken wire is
found at the swaged connection or a crack in the swage,
replace the fitting.
Hooks and Shackles
Hooks and shackles are handy for hauling or lifting
loads without tying them 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 due to overloading, they usually
straighten out and lose or drop their load. When a hook
has been bent by overloading, it should NOT be
Figure 13-25.-Swaged connections.
straightened and put back into service; it should be cut
in half with a cutting torch and discarded.
Hooks should be inspected at the beginning of each
workday and before lifting a full-rated load. If you are
not sure a hook is strong enough to lift the load, by all
means use a shackle.
Hooks that close and lock should be used where
there is danger of catching on an obstruction,
particularly in hoisting buckets, cages, or skips, and
especially in shaft work. Hooks and rings used with a
chain should have about the same strength as the chain.
The manufacturers recommendations should be
followed in determining the safe working loads of the
various sizes and types of specific and identifiable
hooks. All hooks for which no applicable manu-
facturers recommendations tire available should be
tested to twice the intended safe working load before
they are initially put into use.
Mousing is a technique often used to close the open
section of a hook to keep slings, straps, and similar
attachments from slipping off the hook, as shown in
Hooks may be moused with rope yarn, seizing wire,
or a shackle. When using rope yarn or wire, make 8 or
10 wraps around both sides of the hook. To finish off,
make several turns with the yarn or wire around the sides
of the mousing, and then tie the ends securely.
Two types of shackles used in rigging are the
anchor (Fig. 13-27) and the chain (fig. 13-28). Both are
available with screw pins or round pins.
Shackles should be used in the same configuration
as they were manufactured. Never replace the shackle
pin with a bolt. when the original pin is lost or does not
fit properly, do not use the shackle. All pins must be
straight and cotter pins must be used or all screw pins
must be seated.
A shackle should never be pulled from the side,
because this causes the shackle to bend which reduces
the capacity tremendously. Always attach a screw pin