PULLEYS

Tools for access and rigging

Pulleys are used to haul up equipment or raise a person in a rescue situation. Some pulleys have an integrated rope clamp to make certain tasks easier. Specialized pulleys also allow for movement along a rope or cable: for moving loads or evacuating a person.

Pulleys are divided into five families:

• Progress capture pulleys have an integrated progress capture device so a hauling system can be quickly installed,
• Single pulleys can be used in all systems,
• Prusik pulleys are designed for use with a self-jamming Prusik hitch to build a lightweight progress capture system,
• Transport pulleys are designed for Tyrolean traverses with rope or cable,
• Specialized pulleys are designated to certain specific applications (moving along mechanical lift cables, passing knots, etc.)

Two factors determine a pulley’s efficiency:

• Sheave size: the larger the sheave diameter, the higher the efficiency,
• Bushings and bearings: self-lubricating bushings are efficient, but they must be regularly maintained. Ball bearings are very efficient. Since they are sealed, they do not require any maintenance.

The design of the pulley determines how the pulley is attached to the rope:

• Pulleys with fixed side plates must be used with symmetrically shaped carabiners. They are quick and easy to install.
• Pulleys with swinging side plates must be opened to load the rope. They work with all carabiner types.