Sling tension

Confirm angle and load conventions

An angle measured from vertical is not the angle from horizontal used here. The rise-and-span mode derives the angle from the stated geometry. Include the weight of lifting equipment carried by the sling and do not assume every physical leg shares load equally.

Compare with the correct rated capacity

Use the sling's capacity for the actual hitch and conditions, not an unrelated catalog breaking strength. Center of gravity, unequal loading, bends, edges, attachment points, and dynamic effects need a qualified lifting assessment. The calculated tension is a load estimate, not authorization to perform a lift.

Checking the angle convention with simple cases

For an ideal symmetric two-leg arrangement at 90 degrees from horizontal, each effective leg carries half the factored weight. At 30 degrees from horizontal, each leg carries the full factored weight because sine of 30 degrees is one half. This comparison illustrates why flatter legs can be heavily loaded even when the lifted object's weight has not changed.

The geometry mode uses rise and span to derive the represented angle. Confirm whether the span describes the full distance between attachment points or the half-span used by the geometry before transferring drawing dimensions. Include lifting accessories carried by the sling where they contribute to the supported weight. The effective leg count must reflect a justified load-sharing assumption; the number of installed legs alone does not establish it. Unequal lengths, an offset center of gravity, attachment flexibility, and dynamic motion can invalidate the symmetric model. Compare only with the rated capacity for the actual sling and hitch, and have the complete lift arrangement assessed before use.

Formula

Leg tension = total weight × dynamic multiplier / (effective legs × sin(angle from horizontal)).