Chapter 6 — Slings and Sling Hitches 87
Prefabricated Bridle Slings. Bridle sling assemblies are often manufactured as a unit that cannot be disassembled or modified in the field. See Figure 6-15. These assemblies have sling legs joined at a master link, which is a steel ring. The master link must be rated to carry the combined load of all of the sling legs. If a single rated load is provided for a bridle sling, it is assumed to be for a 60° bridle hitch. If a prefabricated bridle sling has more legs than needed for an application, the unused legs should be secured to prevent them from interfering with the load or other rigging during the hoisting operation. The loose ends can be connected to the master link with a shackle.
not on the tip, and not bind or overlap each other. Synthetic fiber slings are particularly prone to pinching or bunching due to limited space on a hook. To avoid these problems, a larger shackle or master link should be used. See Figure 6-16.
Shackles in Bridle Hitches
SHACKLE MORE ROOM FOR GATHERING SLINGS
Prefabricated Bridle Slings
MASTER LINK
RATED LOAD INFORMATION APPLIES TO ENTIRE SLING SYNETHIC FIBER SLINGS
PERMANENT ATTACHMENTS
Figure 6-16. Shackles can be used to form field-assembled bridle slings, particularly when all the sling eyes will not safely fit within the hoist hook.
END FITTINGS (VARY)
If a bridle hitch incorporates basket or choker hitches, there are some special considerations. First is the potential slippage of slings toward the center of the load. Second, when using synthetic web slings in low sling angles, the load may bear on only one edge of the sling material, which can damage the sling. See Figure 6-17. Both problems can be alleviated by using longer slings in order to increase the attachment sling angle. Alternatively, spreader or lifting beams can be used to avoid these problems altogether.
Lift-All Company, Inc.
Figure 6-15. Prefabricated bridle slings have sling legs permanently attached to a master link.
Field-Assembled Bridle Slings. Bridle hitch configurations can also be assembled from individual slings and rigging hardware. When slings are grouped in a hook, they should sit in the base or bowl of the hook,
A bridle hitch is typically the most stable way to rig a load for hoisting, assuming that suitable lift points are available on the load. Bridle hitches are also versatile. Multiple bridle hitches can be nested to gather many lift points gradually into one. For example, bridle hitches can be used in tiers so that a single crane hook can be connected to many lift points. Lifting bars are also often used with bridle hitches to control sling angles.