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.

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

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. 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. 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.

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. 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. 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. Raising systems are essential in any rescue or rigging scenario in which loads are lifted using rope.