3/4" Whoopie Sling

A 3/4 in whoopie sling is an adjustable rope sling made from hollow-braid rope, with a fixed eye at one end and an adjustable eye at the other. Arborists use them to hang heavy rigging blocks on trunks of any size, and the same design is popular in sailing for adjustable rigging.

How a whoopie sling works

A whoopie sling uses a hollow-braid rope buried inside itself. Slide the bury to make the adjustable eye larger or smaller; under load the outer braid squeezes down on the inner section and holds. The result is one sling that fits a small stem or a big trunk without wasting length or wraps.

Sailors use the same trick for adjustable shrouds and lashings, which is why you see the term whoopie sling with sailing. In tree work the 3/4 in size is for heavy rigging blocks and big wood.

Because it adjusts, one whoopie can do the work of several fixed-length slings, which saves space and weight in the rigging bag. It is also kind to bark, since there is no long tail wrapped around the trunk.

Use and inspection

Wrap the trunk, pass the fixed eye through the adjustable eye or connect with a shackle or carabiner, and snug it down. Make sure the adjustable section has the minimum bury the maker specifies before loading.

Check for cuts, abrasion, glazing and stiff or crushed spots before each use. Retire a sling that has been overloaded. Rigging slings are not life support; size every part of the system for the load and work to ANSI Z133.