What occurs due to the tightening of a loop that is restrained from untwisting?

The correct answer is kinking. When a loop is tightened while being restrained from untwisting, the result is often a deformation known as kinking. This occurs because the material cannot relieve tension by rotating or twisting in the usual manner. Instead, the stress leads to a sudden change in direction, creating a sharp bend or kink in the material, which can compromise its structural integrity.

Kinking is especially common in ropes and cables when they are improperly handled or overloaded. It is critical to understand this phenomenon because kinks can reduce the load-carrying capacity of the rigging or hoisting equipment and may lead to failure under load.

In contrast, twisting describes a different action that occurs when a rope or line is twisted around itself without the constraint of a loop. Fraying refers to the wear and damage of the fibers that occurs over time due to abrasion and stress, but it is not a direct result of the tightening loop scenario described. Breaking, while a possible outcome in extreme cases, would typically result from excessive stress and not solely from the described tightening of a restrained loop.