What does the term "sheave" refer to in rigging?

The term "sheave" specifically refers to a wheel or disk that has a groove around its circumference designed to accommodate a rope or cable. In rigging, sheaves are integral components of pulley systems and play a crucial role in changing the direction of force applied to a rope or cable. This allows for smoother movement and the ability to lift heavy loads more efficiently.

Understanding what a sheave is helps in various applications, such as ensuring that ropes run smoothly and reducing friction in a rigging setup. This understanding is vital for manipulating mechanical advantage and ensuring safe rigging practices. While a pulley system involves multiple components, including sheaves, the term itself is specifically about the wheel or disk and its groove. This precision in terminology is critical for clear communication in the theatre rigging profession.