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.

Mechanical advantage systems rope rescue.

A system s mechanical advantage is expressed as a ratio using a colon. 3 1 system the 3 1 is the classic mechanical advantage system used by rescuers. 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. 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.

Components of a mechanical advantage system. 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. 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.

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. 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. Understanding how mechanical advantage is calculated will help you create the perfect pulley configuration for any rescue mission you re up against. 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.