Mechanical Advantage Systems Rope Rescue

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.

Mechanical advantage systems rope rescue.

Understanding how mechanical advantage is calculated will help you create the perfect pulley configuration for any rescue mission you re up against. In a 3 1 mechanical advantage system mas a 300 lb load would feel like 100 lbs and 3 feet of rope will move the load up 1 foot. 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. 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.

For example a 2 1 or 3 1 system these are pronounced as a 2 to 1 and 3 to 1. 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. Components of a mechanical advantage system. 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.

3 1 system the 3 1 is the classic mechanical advantage system used by rescuers. Raising systems are essential in any rescue or rigging scenario in which loads are lifted using rope. 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. 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.