When a load is lifted by multiple slings and the angle from vertical is larger, the tension per sling does what?

When a load is lifted by multiple slings and the angle from vertical is larger, the tension per sling does what?

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

Answer: (C)

When lifting a load with more than one sling, the load is shared, but each sling’s share depends on how far the slings are tilted from vertical. As the angle from vertical grows, the vertical component of each sling’s tension becomes smaller, so to keep the same total weight supported, the tension in each sling must increase. With n slings, the vertical balance is n T cos θ = W, so T = W/(n cos θ). As θ increases, cos θ decreases, making T larger. Thus, the tension per sling increases with a larger angle from vertical.

When lifting a load with more than one sling, the load is shared, but each sling’s share depends on how far the slings are tilted from vertical. As the angle from vertical grows, the vertical component of each sling’s tension becomes smaller, so to keep the same total weight supported, the tension in each sling must increase. With n slings, the vertical balance is n T cos θ = W, so T = W/(n cos θ). As θ increases, cos θ decreases, making T larger. Thus, the tension per sling increases with a larger angle from vertical.