Why should a belay line not be put through a change in direction pulley?

A belay line should not pass through a change in direction pulley primarily because the failure of the pulley could create dangerous conditions, leading to a significant fall and shock impact on the belay line. In rescue scenarios, every component of the rigging system is critical, and any point of potential failure must be carefully considered. If a pulley fails while a load is being belayed, the sudden release can result in a disastrous fall or shock load, significantly compromising safety.

This situation emphasizes the importance of maintaining a direct path for belay lines to ensure maximum efficiency and safety. The risks associated with potential equipment failure further underscore the necessity of precise rigging standards in rope rescue operations. Maintaining a straightforward belay system helps to secure the safety of both the rescuer and the subject being rescued.