In rigging, what is the difference between the center of gravity and the center of lift?

• A. Center of gravity is where weight acts within the load; center of lift is where the rigging attaches to the load; both influence balance and stability.
• B. Center of gravity and center of lift are the same concept.
• C. Center of gravity is the attachment point of the spreader bar.
• D. Center of lift determines the weight distribution only in unfurling operations.

Answer: (A)

In lifting, two points determine how the load will behave: where the weight acts inside the load, and where the lifting force acts from the rigging. The center of gravity is the point at which the load’s weight can be considered to act; it’s fixed by the mass distribution of the load itself. The center of lift is the point (or the resultant line) where the lifting forces from the rigging act on the load; this depends on how the slings, spreader bar, and attachment points are arranged.

The key relationship is about moments. If the center of lift lines up with the center of gravity, there’s little rotational tendency—the load stays oriented as it is being lifted. If they’re offset, a moment is created that can cause the load to tilt or rotate during hoisting. Because the center of gravity is inherent to the load and the center of lift can be changed by how you rig it, riggers adjust attachments and sling geometry to bring the lift point near the load’s CG and control orientation with tag lines or guides.

That’s why the distinction matters: the center of gravity tells you where the weight acts and how the load will tip, while the center of lift tells you where the lifting force acts and how the load may rotate during lifting. Both influence balance and stability.