How does reeving a sling around a square load affect the SWL/WLL?

When reeving a sling around a square load, the safe working load (SWL) or working load limit (WLL) is affected due to the way the sling distributes the load across its sections. In this case, reeving can create multiple bends and angles in the sling, which can reduce its lifting capacity.

Reeving around a square load typically involves more complex angles and geometries compared to lifting a load that is free hanging or in a straight-line configuration. As the sling bends around the load, there are additional stresses placed on the sling itself, which can lead to a reduction in the effective lift capacity.

In practical terms, when a sling is reeved, manufacturers often recommend a reduction in the SWL or WLL by as much as 50% due to factors like increased friction and the potential for reduced load distribution efficiency. This reduction ensures that safety is maintained, preventing overloading of the sling and minimizing the risk of slippage or failure while lifting.

Therefore, reeving a sling around a square load leads to a significant reduction in the SWL/WLL, which underscores the importance of understanding proper rigging techniques and load configurations to ensure safe lifting operations.