Maximum included sling angle?

Maximum included sling angle?

• A. 45 degrees
• B. 60 degrees
• C. 120 degrees
• D. 90 degrees

Answer: (D)

The key idea is how the sling angle affects the load in each leg. When two sling legs share a load, each leg carries tension T, and the vertical components of those tensions sum to the load. If the included angle between the legs is gamma, and each leg makes alpha = gamma/2 with the vertical, then 2 T cos(alpha) = W, so T = W / (2 cos(alpha)). As gamma increases, alpha increases and cos(alpha) decreases, so the required tension in each leg grows. This means larger included angles drive higher forces on the sling and reduce the margin of safety. At a gamma of 90 degrees, alpha is 45 degrees, so each leg carries T = W / (2 cos 45°) ≈ 0.707 W. This is still within typical sling ratings, and it’s the practical limit manufacturers commonly specify for a two-leg sling configuration. If you tried a larger angle, the per-leg force would rise quickly, making it harder to stay within safe limits and increasing risk. Therefore, the maximum included sling angle is 90 degrees.

The key idea is how the sling angle affects the load in each leg. When two sling legs share a load, each leg carries tension T, and the vertical components of those tensions sum to the load. If the included angle between the legs is gamma, and each leg makes alpha = gamma/2 with the vertical, then 2 T cos(alpha) = W, so T = W / (2 cos(alpha)). As gamma increases, alpha increases and cos(alpha) decreases, so the required tension in each leg grows. This means larger included angles drive higher forces on the sling and reduce the margin of safety.

At a gamma of 90 degrees, alpha is 45 degrees, so each leg carries T = W / (2 cos 45°) ≈ 0.707 W. This is still within typical sling ratings, and it’s the practical limit manufacturers commonly specify for a two-leg sling configuration. If you tried a larger angle, the per-leg force would rise quickly, making it harder to stay within safe limits and increasing risk. Therefore, the maximum included sling angle is 90 degrees.