Mechanical Advantage Systems Rope Rescue

Components of a mechanical advantage system.

Mechanical advantage systems rope rescue.

The first number represents the force on the load and the second number is the force that the rescuers are pulling on the rope. Four to one systems are less popular than 3 1 systems probably because they require an additional pulley and don t offer significantly more mechanical advantage. Notice however that the end of the rope on 2 1 systems is attached to the anchor whereas the end of the rope on 3 1 systems is attached to the load. A raising system using a combination of pulleys to leverage the force applied in lifting is referred to as a mechanical advantage m a system.

It requires less rope than a non piggybacked 2 1 system is reasonably easy to rig is easy to add a progress capture device provides an appropriate amount of mechanical advantage to raise one or two people and with a few tweaks it can be converted into a simple 5 1 system. Understanding how mechanical advantage is calculated will help you create the perfect pulley configuration for any rescue mission you re up against. Raising systems are essential in any rescue or rigging scenario in which loads are lifted using rope. Even if you only need to raise a load 20 feet using a 5 1 you will have to pull a whopping 100 feet of rope and probably reset the system many times.

The downside of systems with a 5 1 or higher mechanical advantage is you have to pull a lot of rope to move the load a short distance. For example a 2 1 or 3 1 system these are pronounced as a 2 to 1 and 3 to 1. However once you learn how to stack a 2 1 on a 2 1 to create a compound 4 1 you ll know how to stack a 2 1 on a 3 1 to create a 6 1 also a less popular system but worth knowing if you are a rigging geek and how to. Whether the end of the rope connects to the anchor or to the load is a subtle difference between mechanical advantage systems that have an even number e g 2 1 4 1 6 1 etc and systems that.