Which type of sheave is employed to equalize tension in opposite parts of the rope?

The correct answer is that the idler sheave is designed to equalize tension in opposite parts of the rope. This function is crucial in various rigging and lifting operations, where maintaining balanced tension helps prevent undue stress on the rope and equipment, enhancing safety and efficiency.

Idler sheaves serve as a guide for the rope and allow it to change direction without creating additional tension or friction that could occur with other types of sheaves. By distributing the load evenly, the idler sheave helps to extend the life of the rope and minimizes the likelihood of failure during operation.

Other types of sheaves have different primary functions. For example, a main sheave typically serves as the primary point of load-bearing in a pulley system but may not specifically address tension equalization. Runner sheaves allow the rope to run smoothly through a system but are focused on motion rather than tension balance. Guide sheaves mainly ensure the correct path for the rope, but don't necessarily play a role in equalizing tension. Understanding the distinct roles of each sheave type is essential in selecting the right components for rigging setups.