If trickline is your domain, a ratchet is what you probably prefer. But if you’re tempted by longlines, a pulley system is a must. So what it is and how does it work?
A pulley system is a tensioning system that comprises of several pulleys (block and tackle), a rope, a rope brake, an ascender and connectors. Besides great efficiency, a pulley system provides a great variability as well; all parts can be combined. That leaves you with taking only the stuff you really need when going on the line.
Two double pulleys (EQB Minima FX) or two quadruple pulleys (EQB Quatron FX) make the system base. The front pulley is tackle (movable) which increases the system efficiency while the back one is a non-movable block pulley (at the anchoring point) leading the line without affecting its mechanical efficiency.
Basic double pulley system (e.g. Minima FX) efficiency ratio is 5:1 whereas two quadruple pulleys (Quatron FX) increase the ratio to 9:1. Efficiency can be increased further by a multiplier which is of course yet another simple pulley system attached to the loose end of the main pulley rope. Either a simple multiplier that multiplies the main pulley system by 3:1 ratio, or a double multiplier (with an extra pulley) multiplying the main pulley system by 5:1 ratio.
A rope brake plays an important role in the pulley system; either a primitive system where the rope is self-locking. Brakes like Elephant FX are lighter and cheaper but they are less efficient due to increased friction resulting in greater rope attrition. Cam brakes (eg. Grigri etc.) are more efficient but far more expensive and heavier, too.
A rigging plate, such as EQB Tribit or EQB Alien, can be used to mount the rope break. Alternatively, extra anchoring sling can be used instead as well. Some pulley designs allow attaching the rope brake directly to the pulley making the use easier. For example both Minima and Quatron systems are based on this design.
A static rope of corresponding diameter (mostly 8-11mm) is used to connect the pulleys. The rope can be made of polyamide (PAD), polyester (PES) or other high-tech materials such as dyneema or vectran. The lower the rope stretch (PAD > PES> hi-tech), the greater the pulley system efficiency.
The pulley system design affects its efficiency too. Used bearings (bushings or ball bearings, which are much more efficient under heavy load), roller diameter (the greater the better) and other aspects, too.