Slings, Shackles & Steels
Definition
Slings, shackles and steels are the soft and hard connectors between a load and the structure. Round slings (endless polyester) are colour-coded by WLL under EN 1492-2: purple 1 t, green 2 t, yellow 3 t, grey 4 t, red 5 t, brown 6 t, blue 8 t and orange 10 t. Textile slings to EN 1492 are built with a 7:1 safety factor, and the WLL on the label applies to a straight vertical lift; a choke hitch or a basket hitch changes the rating according to the mode factors given by the manufacturer. Shackles (bow or dee) carry a stamped WLL and connect slings to steels or hard points; in Europe they are made to EN 13889, and ASME B30.26 covers rigging hardware in the United States. Steels are wire rope slings, made to EN 13414-1 in Europe and used where a soft sling would chafe or burn.
In the field
Both the colour and the label of a round sling are read, because a faded sling cannot be identified by its colour alone. Shackles and hooks are not side-loaded, screw-pin shackles are moused or otherwise secured so that the pin cannot back out, and a choke hitch reduces a sling's WLL below its straight-lift rating.
Sources
- EN 1492-2, Textile slings — Roundslings : code couleur par CMU (violet 1 t … orange 10 t) · h-lift.com
- EN 1492-1 : élingues textiles, coefficient de sécurité 7:1, coefficients de mode selon le montage · h-lift.com
- EN 13414-1, Steel wire rope slings : coefficient 5, manilles conformes à l'EN 13889 · knowledge.bsigroup.com
- ASME B30.26, Rigging hardware : manilles et accessoires aux États-Unis · asme.org