# The 3:1 Pulley System

Here we have a 3:1 mechanical advantage. First one end of the rope is attached directly to the load, this is then passed around an anchored pulley (pulley B) and returns back to the load where it is passed through pulley A which has been fixed to the load.

This forms the 3:1 mechanical advantage, finally the rope is redirected by pulley C back down to the user who applies an effort of 30kg to raise the 90kg load.

An easy way to calculate the ratio of a pulley system is to count the amount of lines that apply effort on the load. In this system there are three ropes that exert effort on to a load of 90kg, so each rope is supporting 1/3 of the loads weight (30kg). Pulleys B & C and their anchors are subject to 60kg each.

## Angular Vector Forces

Angular vector forces occur when ropes are passed through a deviation or a directional pulley. Dependent on the angle created, this can have a multiplying…

## Vector Forces

Vector forces become apparent whenever there is an internal angle greater than 0° between two or more rigging components or anchorage points. For ease of…

## The 4:1 Pulley System

This pulley system provides a 4:1 mechanical advantage. The user is required to apply a force of 25kg to raise this 100kg load, for every…

## Fall Factors

A fall factor is a simple representation of the severity of a fall. It can be used to evaluate the potential loadings exerted on the…

## The 1:1 Redirect Pulley System

In the illustration to the right we have a rope attached to a load weighing 100kg. The rope has been passed through a pulley which…

We need you! Become a BETA Tester and help with the development of the ropebook platform. We’d like to put together a selected group of Testers to give us some feedback on the current BETA stage of the site.