Which of the following best describes the effect on nominal strength when rope is bent around sheaves or hooks?

• A. Nominal strength is unchanged
• B. Nominal strength increases
• C. Nominal strength is reduced
• D. Rope fails immediately

Answer: (C)

When rope is bent around sheaves or hooks, the load path becomes uneven and the rope experiences bending stresses in addition to the tension. The fibers on the outer side are pulled more and the inner fibers are compressed, creating a concentration of stress that reduces the rope’s ability to carry load. This bending damage accumulates with tighter bends or more wraps, so the rope’s nominal strength—its rated breaking strength in a straight pull—decreases once it’s bent. That’s why rigging guidelines specify minimum bend radii and avoid sharp bends to preserve strength.