At a 60-degree angle, the sling leg load is what percentage?

At a 60-degree angle, the sling leg load is what percentage?

• A. 75%
• B. 100%
• C. 115%
• D. 130%

Answer: (C)

When two legs of a sling share a load, the tension in each leg depends on how far the legs splay apart. If the total weight being lifted is W and the angle between the legs is α, each leg carries a tension T given by 2 T cos(α/2) = W, since each leg forms an angle α/2 with the vertical. For an included angle of 60°, half of that angle is 30°, and cos(30°) ≈ 0.866. So each leg carries T = W / (2 cos 30°) ≈ W / (2 × 0.866) ≈ 0.577 W. If you compare this to the load per leg when the legs are vertical (which would be W/2 per leg), the leg load increases by a factor of 1 / cos(α/2). With α/2 = 30°, that factor is 1 / cos 30° ≈ 1.155, i.e., about 115%. So, at a 60-degree angle between the sling legs, the sling leg load is about 115% of the vertical-leg load.

When two legs of a sling share a load, the tension in each leg depends on how far the legs splay apart. If the total weight being lifted is W and the angle between the legs is α, each leg carries a tension T given by 2 T cos(α/2) = W, since each leg forms an angle α/2 with the vertical.

For an included angle of 60°, half of that angle is 30°, and cos(30°) ≈ 0.866. So each leg carries T = W / (2 cos 30°) ≈ W / (2 × 0.866) ≈ 0.577 W.

If you compare this to the load per leg when the legs are vertical (which would be W/2 per leg), the leg load increases by a factor of 1 / cos(α/2). With α/2 = 30°, that factor is 1 / cos 30° ≈ 1.155, i.e., about 115%.

So, at a 60-degree angle between the sling legs, the sling leg load is about 115% of the vertical-leg load.