As the angle between the sling legs and the vertical increases, the force in each sling does what?

• A. Decreases
• B. Increases
• C. Stays the same
• D. Varies with angle

Answer: (B)

When two slings share a load, each sling must provide a vertical component of force that adds up to the total weight. As the angle between the sling legs and the vertical increases, the vertical component of each sling’s tension decreases for a given tension, so the tension in each sling must rise to balance the same weight. Mathematically, with two slings, the tension in each leg is T = W / (2 cos θ), where θ is the angle from vertical. As θ increases, cos θ decreases, causing T to increase. This means the force in each sling grows with the angle, and it can become very large as the angle approaches 90 degrees.