The working load limits of slings made from general engineering ropes to BS EN 12385-4 should conform to BS EN 13414-1: 2003. Note that the working load limits shown are based on the assumption that soft-eyes of single-part slings are used over bearing points of not less than twice the normal diameter of the rope. All sling ropes must be ordinary lay.
The Safe Working Load will normally be equal to the Working Load Limit but in some circumstances it may be less e.g. If the sling is used in choke hitch SWL=WLL x 0.8 .
BS EN 13414-1 covers only those sling assemblies that have legs of equal nominal length, diameter, construction and tensile grade. While sling assemblies with legs of unequal length may be made up generally in accordance with the requirements of BS EN 13414-1, it must be stressed that their rating requires special consideration by a competent person.
In all cases, where hooks or shackles are used, the WLL of the hooks and shackles shall not be less than that of the leg to which they are attached.
When using multi=leg sling assemblies remember that increasing the angles between the legs will increase the load in each leg. Examine all slings before use and discard any that are defective. Slings which are found to be unfit for use should be destroyed by cutting them up - not put on a refuse dump. "Hooking back" to the leg is not recommended. The Working Load Limit of slings is effected by the method of usage. Check that the crane hook is positioned over the loads centre of gravity to prevent swinging when the load is being raised. Correct signals, according to the recognised code, should be given to the crane driver. The signals must be given by the person responsible for the lift and nobody else.
Keep wire rope slings away from welding and flame cutting operations. The Law requires that all lifting equipment must be examined by a competent person at regular intervals. This includes wire rope slings.
Certex can manufacture slings to DNV 2-7.1 in their approved facility in Montrose.