What is the effect on the capacity slings as the included angle between slings increases?

What is the effect on the capacity slings as the included angle between slings increases?

• A. Capacity stays the same
• B. Capacity is reduced
• C. Capacity becomes unpredictable
• D. Capacity increases

Answer: (B)

When multiple slings share a lift, the angle between them directly affects how much load each sling must carry. If two slings are used and the included angle between them is 2α, each sling forms angle α with vertical. The vertical components of the two sling tensions must support the load, so 2 T cos α = W, where T is the tension in each sling and W is the load. The slings can withstand up to their rated capacity C, so we require T ≤ C. This gives the maximum load the system can lift as W_max = 2 C cos α. As the included angle increases, cos α decreases, so W_max decreases. In short, widening the angle reduces the overall lifting capacity of the sling arrangement.

When multiple slings share a lift, the angle between them directly affects how much load each sling must carry. If two slings are used and the included angle between them is 2α, each sling forms angle α with vertical. The vertical components of the two sling tensions must support the load, so 2 T cos α = W, where T is the tension in each sling and W is the load. The slings can withstand up to their rated capacity C, so we require T ≤ C. This gives the maximum load the system can lift as W_max = 2 C cos α. As the included angle increases, cos α decreases, so W_max decreases. In short, widening the angle reduces the overall lifting capacity of the sling arrangement.