multisheave

Multisheave refers to a mechanical arrangement that uses multiple grooved wheels, or sheaves, within a single frame or block. Each sheave guides a rope, cable, or belt and can be paired with other sheaves to route lines and change leverage.

Typically, a multisheave block consists of a frame or housing that holds several sheaves on separate or shared axles, with grooves sized to accommodate a specific rope or cable diameter. Bearings, pins, and fasteners secure the assembly.

The arrangement increases mechanical advantage by distributing load across multiple lines or by changing the effective number of rope segments supporting a load. By selecting which lines wrap around which sheaves, designers can achieve different trade-offs between speed and force, and can route lines around obstacles more easily in constrained spaces.

Common applications include crane blocks, sailing rigging, theater fly systems, and elevator or hoist equipment.

Design considerations include alignment, load distribution among lines, wear on grooves, lubrication, and the overall weight. Maintenance involves inspecting for uneven wear, contaminated grease, and ensuring proper rope diameters and compatible sheave radii to prevent damage.

See also: pulley, block and tackle, sheave.