Mechanical advantage calculator from alpinerecreation.com
I recently came across this clever online tool from alpinerecreation.com, a New Zealand based guiding company.
It’s a mechanical advantage calculator, very cool!
This is an excellent way to instantly see some of the forces involved with different rigging methods, and how using a carabiner rather than a pulley can change the efficiency of your system.
(Works fine on a mobile phone but it's easier to see the big picture on a wider computer screen.)
Choose your hauling system (2:1. 3:1, 5:1, 6:1, etc.)
Choose your components (Micro Traxion, rescue pulley, large carabiner, small carabiner, etc.)
Choose your load (default is 100 kg)
Choose your units (percentage of load, kg, or kN)
Press “Calculate” and it gives you values and forces all the way through the system!
Here’s a screen grab showing values for a 3:1 Z drag, using a Micro Traxion as the progress capture and a good quality pulley on the “tractor”.
image: https://www.alpinerecreation.com/mechanicaladvantagecalculator.html