What should never be done with fiber rope over sheaves?

Fiber rope is sensitive to abrasion and damage from sharp edges. When fiber rope is run over sheaves, it is particularly important to avoid contact with surfaces that can cause excessive wear or cut into the rope's fibers. Running fiber rope over wire ropes can create a harsh surface interaction, as the wire ropes can have rough spots, sharp edges, or surface imperfections that will damage the fiber rope over time.

This means that using fiber rope over wire ropes can lead to fraying, loss of strength, or complete failure of the fiber rope, creating hazardous situations. Therefore, it is critical to use sheaves that are smooth and compatible with fiber ropes, ensuring the longevity and effectiveness of the rigging operation. This principle of protecting the integrity of fiber ropes is fundamental in rigging and lifting practices.