What is the definition of sling angle in rigging?

Sling angle in rigging is fundamentally concerned with the relationship between the sling and the horizontal plane. It specifically refers to the angle formed by the legs of the sling with respect to that horizontal plane. When lifting a load, the angle of the sling legs affects the distribution of weight and can influence the effective lifting capacity of the sling.

As the sling angle increases, typically as it moves away from the vertical, the tension within the sling increases. This tension must be carefully managed because too steep of an angle can lead to higher forces on the sling and rigging components, posing a risk of failure. Therefore, understanding and correctly calculating the sling angle is crucial for safe and effective rigging practices.

The other options refer to different aspects of rigging. The angle between the sling and the load pertains to how the sling interfaces with the load, which is important but does not provide the same context as the angle to the horizontal plane. The angle of the load to the ground refers more to the orientation of the load itself rather than the rigging components. The angle between two pulleys is a separate consideration in pulley systems and doesn't pertain to sling angles specifically.