Arborist Shackle

An arborist shackle is a simple, strong connector for joining slings, rigging rings and blocks. It is a staple in the rigging bag for the times a carabiner is the wrong tool, such as heavy static connections and hardware that stays put for the whole job.

Where a shackle fits

In rigging, a shackle is the go-to when you need a strong connection that will not be opened and closed all day. Use it to hang a block on a sling, join a ring to a sling eye or connect hardware on a speedline anchor. It has a lot of strength for its size.

Size it by the working load marked on the shackle, not by feel, and make sure the bow is wide enough for the sling or eye without pinching it. See other rings and rigging hardware for more connectors.

Keep a few sizes in the rigging bag. A small shackle handles light hardware on pruning jobs, while bigger removals call for a larger shackle that matches the block and sling you are using. Mixed sizes mean you are not tempted to use the wrong one because it is the only one on the truck.

Use and inspection

Seat the pin fully and snug it. On a screw-pin shackle, check it during the job, since rope movement can back the pin out. Load the shackle in line with its body and avoid side loading.

Before each job, look for bending, a stretched bow, cracks, corrosion and damaged threads, and retire any shackle that has been overloaded or will not close cleanly. Rigging gear is not for life support. Follow ANSI Z133 and the maker's ratings, and keep rigging to trained crews.