How does the center of gravity of a load influence crane selection and rigging procedures?

The center of gravity (CG) of a load significantly influences crane selection and rigging procedures because it affects the load's stability during lifting and the stresses imposed on the crane. The center of gravity is the point where the entire weight of an object is concentrated. If the CG is not directly below the crane's hook, the load will tend to tilt or swing, creating instability. This necessitates the use of a crane with sufficient capacity to handle the increased dynamic loading caused by the off-center CG and can also require the use of multiple lifting points to balance the load. In rigging, it is crucial to identify the CG accurately to ensure the load remains stable throughout the lift. This often involves using slings of different lengths or adjusting the position of the lifting points to align the CG directly below the hook. An example would be lifting a large piece of machinery: If the CG is closer to one end, rigging the load with a single sling at the center would cause it to tip. Instead, two slings of unequal length would be used to balance the load and keep it level during the lift.