Double mariners

[mark_sauls]

So,
pulling on the tail of a 3:1 with a 2:1 gives you 7:1? How does that math work?

http://www.petzl.com/files/all/product-experience/SPORT/PE-MICROTRAXION-SP-EN.pdf

see page 7

 

[Treebobb]

You are looking at it as if it were a compound pulley system but it's a complex. They don't calculate the same. On Rope has a good section on this explaining the T- method. Here is something I found online that will help.
http://bothellfire.org/TechRescue/Rope/PulleySystems.pdf

 

[mark_sauls]

Never mind I got it:

http://efclimbers.net/wp-content/uploads...-systems-ma.pdf

see Figure 10 pg 16

 

[mark_sauls]

Thanks Treebobb.