Show me the 9:1


OK, I’m on a SAR team and need to know fancy systems, or I’m a river guide who might need to pull a wrapped raft off a midstream boulder, or I like to drive offroad and need to know how to pull my truck out of the ditch. I'm ready for the 9:1! How do I do it?

Well, if you read this far, you're ready for the fancy stuff. A 9:1 is a compound system, with a 3:1 stacked on top of another 3:1. Remember, with a compound system, the forces of each section are multiplied together to get the final MA, so a 3:1 on a 3:1 gives you a 9:1.

Many people (like me!) find looking at a diagram of a 9:1 makes their head spin. But as we like to stay around here, it's a better show than a tell. When you see it demonstrated properly it's actually pretty simple. Here is a nice video that shows you how to do it.


And, if you're the diagram type, here’s a pretty slick example of a 9:1.