Useful information about pulleys

What are pulleys used for in work at height and rescue operations?

Pulleys redirect ropes in a controlled manner and reduce friction when lifting, lowering or moving people and loads. They are used in hauling systems, rescue systems, rope access techniques and rigging configurations. By redirecting the rope in a targeted manner, pulling directions can be changed, mechanical advantage can be created and work or rescue procedures can be made more efficient.

SKYLOTEC pulleys are used in technical rescue, arboriculture, rope access and professional lifting and recovery operations. The range extends from compact single pulleys to double and triple pulleys and multifunctional devices with an integrated rope clamp or progress-capture mechanism.

What advantages do pulleys offer compared with redirecting a rope directly?

When a rope is redirected directly over a karabiner, an edge or another surface, comparatively high friction is generated. This increases the force required and subjects the rope to greater wear. A suitable pulley, by contrast, guides the rope over a rotating sheave and therefore supports smoother and more controlled movement.

The reduced friction loss is particularly noticeable over longer lifting distances, during repeated movements or with heavier loads. Pulleys make it easier to retrieve ropes, improve the operation of hauling systems and can reduce the physical strain on users. However, they do not replace the professional planning of the complete system.

What are the differences between single, double and triple pulleys?

Single pulleys feature one sheave and are suitable for simple redirections, compact rescue configurations or changing the pulling direction. They require little space and can be flexibly combined with karabiners, rigging plates and other system components.

Double pulleys guide two rope strands in parallel and are particularly suitable for hauling systems or redirecting two ropes. Triple pulleys enable even more complex configurations and greater theoretical mechanical advantages. The ORBITER H, for example, is designed as a triple pulley for hauling systems with a reduction factor of 6. The required number of sheaves depends on the planned hauling system, the available space and the load to be moved.

How do hauling systems with pulleys work?

A hauling system distributes the load to be moved across several load-bearing rope strands. This reduces the theoretically required pulling force while simultaneously increasing the pulling distance. The more load-bearing rope strands integrated into the system, the greater the potential mechanical advantage.

In practice, the actual reduction in force is influenced by friction, pulley efficiency, rope routing and angles. Single or double pulleys may be sufficient for simple configurations. Complex rescue and recovery systems are often assembled using several pulleys, rigging plates and a suitable progress-capture device.

When is a pulley with a progress-capture mechanism or integrated rope clamp useful?

A progress-capture mechanism prevents an already raised load from running back uncontrollably. This allows the rope to be secured between individual pulling movements. This function is particularly useful in hauling systems, recovery operations and rescue systems in which loads are lifted in stages.

Devices such as the UP LOCK combine a double pulley with a rope clamp and Freelock system. Multifunctional devices such as the CRIC or ROLLNLOCK combine, depending on the application, the functions of a pulley, rope clamp, ascender and progress-capture device. This can reduce the number of individual devices required in the system.

What advantages do ball-bearing pulleys offer over plain bearings?

Ball-bearing pulleys are designed for particularly low-friction movement and are suitable for applications involving frequent rope movement, longer lifting distances or increased efficiency requirements. They are therefore frequently used in professional hauling systems and rescue systems.

Pulleys with plain bearings or self-lubricating bushes have a simpler and more robust construction. They may be suitable for applications involving less movement, compact systems or environments in which a durable design is the priority. The bearing type should be selected according to the frequency of use, load and desired efficiency.

Which pulleys are suitable for rescue and recovery?

For rescue and recovery operations, pulleys must be suitable for the planned load, the rope diameter used and the complete rescue system. Single pulleys can be used for simple redirections, while double pulleys and systems with a progress-capture mechanism enable more complex hauling systems and controlled lifting operations.

Products such as the EASY RESCUE are designed for specific rescue applications. The pulley can be used on tensioned wire ropes and combines the sheave with an anchor point and a double-action snap hook. Other models such as the CASTOR, CASTOR DOUBLE, POLLUX or ORBITER H are suitable for hauling systems and load systems with different configurations.

Which pulleys are suitable for arboriculture and rope access?

In arboriculture, pulleys are used, among other purposes, to reduce friction in climbing systems and guide ropes in a controlled manner. The ORBITER A, for example, was developed to optimise friction-hitch systems and its design prevents twisting and lateral impacts.

In rope access, compact pulleys, double pulleys and multifunctional devices are used for ascending, equipment transport, redirection and rescue. Depending on the configuration, they can be combined with rope clamps, karabiners and rigging plates. It is essential that all components are compatible in terms of rope diameter, load and intended application.

What roles do rope diameter, working load and efficiency play?

The rope diameter used must be within the range approved for the pulley. A rope that is too thick cannot run cleanly within the sheave, while a rope that is too thin may not suit the geometry or intended application. The SKYLOTEC range includes pulleys for different rope diameters, for example from 8 to 11 millimetres or up to 13, 14 or 15 millimetres.

The Working Load Limit, minimum breaking strength and efficiency must also be considered. The Working Load Limit describes the permissible working load within the intended application. Efficiency determines how much of the theoretical mechanical advantage of a hauling system can actually be used in practice. Only systems specifically approved for rescue and personal protection may be used for these applications.

Which standards apply to professional pulleys?

EN 12278 is particularly relevant for pulleys used in mountaineering, rope access and rescue. Depending on the design and additional functions, further standards may apply, such as EN 567 or EN 12841 for devices with integrated rope clamps and EN 795 for certain systems with an anchoring function.

The specified standard must therefore always be checked for the individual product. A pulley with an integrated clamp, anchor point or multifunctional capability may comply with different requirements from a conventional single pulley. The manufacturer’s specifications regarding rope compatibility, working load and operating limits must also be followed.

How do you choose the right pulley for the application?

The first step is to determine whether the pulley is required for a simple redirection, a hauling system, a progress-capture function, rope access or a rescue system. This determines the required number of sheaves, the necessary attachment points and any additional functions.

The rope diameter, Working Load Limit, bearing type, efficiency and standard must then be checked. A compact single pulley such as the ORBITER A or ORBITER M may be suitable for simple redirections. Models such as the UP ROLL, ORBITER H, POLLUX or CASTOR may be considered for hauling systems. If a progress-capture mechanism or rope clamp is also required, the UP LOCK, CRIC or ROLLNLOCK may be the more suitable solution.