Headroom & slinging methods
Use of lifting beams or spreader beams assist in overcoming headroom problems and these can be purpose built by Nobles to comply with all relevant standards and regulations.
An endless sling shall never have a working load limit greater than 1.5 times the WLL of a sling leg sling.
In the examples shown the WLL shall not be greater than 0.75 times the WLL of the chain to which it is attached.
Adjustable Slings Using Shortening Hooks
Nobles can incorporate shortening hooks into all sling assemblies rendering them adjustable.
Shortening hooks in multi-leg slings will adjust the leg length but care must be taken to ensure that no one leg is overloaded as a result. Bear in mind that if the legs are not equally disposed about vertical, the leg making the smallest angle to the vertical will carry a larger share of the load.
Shortening hooks are the preferred devices for adjusting leg length as they maintain the correct 'in line loading' of the chain
so that the rating is not affected.
Some grab hooks that lock onto a link of the chain for this purpose require a 25% deration. Cradle grab hooks, which fully support the chain link, do not require a deration.