How do sling angles affect the effective load on each sling leg, and what formula is used for calculation?

Sling angles significantly affect the effective load on each sling leg because as the angle between the sling legs decreases (becomes more horizontal), the force on each leg increases. This is due to the vertical component of the force in each sling leg needing to support half of the load's weight, and as the angle decreases, the required force in each leg increases to maintain the same vertical component. The formula used for calculation is: Sling Leg Load = (Load Weight / Number of Sling Legs) x (Sling Length / Sling Height), where Sling Height is the vertical distance from the load to the point where the slings connect at the hook. As the sling height decreases (resulting in a smaller sling angle), the sling leg load increases. For example, if a 10,000 lb load is lifted with two slings, and the sling angle is 30 degrees, each sling leg will bear a load significantly greater than 5,000 lbs due to the increased tension caused by the shallow angle. It is crucial to keep sling angles within safe limits, typically recommended to be no less than 30 degrees, to prevent overloading the slings and causing failure.