As a boom is lowered toward the horizontal, what happens to the load radius and rated capacity?

When a boom is lowered toward the horizontal, the load radius increases. The load radius is the horizontal distance from the center of the rotation of the hoisting equipment to where the load is being lifted. As the boom angle reduces, this distance increases because the boom extends further out horizontally.

As a result of the increasing load radius, the rated capacity of the hoisting equipment decreases. The rated capacity refers to the maximum amount of weight that the hoisting equipment can safely handle at a given radius. When the load radius increases, the lifting equipment's mechanical advantage changes, resulting in a reduced capacity to lift heavier loads.

This relationship between load radius and rated capacity is critical in rigging and hoisting practices, as understanding it ensures safety and prevents accidents when moving loads.