Careful inspection of the wires leading into these connections is 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.

Figure 6-56.- Twin-base wire rope clip.

HOOKS AND SHACKLES.- Hooks and shackles are handy for hauling or lifting loads without tying them directly to the object with 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 NEVER be 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 a 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.

Figure 6-57.- Swaged connections.

The manufacturer's 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 manufacturer's recommendations are available should be tested to twice the intended safe working load before they are initially put into service.

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 figure 6-58.

Hooks may be moused with rope yarn, seizing wire, or a shackle. When using rope yam or wire, make 8 to 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. 6-59) and the chain (fig. 6-60). Both are available with screw pins or round pins.

Shackles should be used in the same configuration as they were manufactured. All pins must be straight and cotter pins must be used or all screw pins must be seated. When the original pin is lost or does not fit properly, do not use the shackle. Never replace the shackle pin with a bolt.

A shackle should never be pulled from the side. This causes the shackle to bend reducing its capacity tremendously. Always attach a screw pin shackle with the screw pin on the dead end of the rope. If placed on the running end, the movement of the rope may loosen the pin.

Figure 6-58.- Mousing.

Figure 6-59.- Anchor shackles.

Figure 6-60.- Chain shackles.

Shackles are moused whenever there is a chance of the shackle pin working loose and coming out due to vibration. To mouse a shackle, simply take several turns with seizing wire through the eye of the pin and around the bow of the shackle. Refer to figure 6-58 for proper mousing.