PULLEY SYSTEMS
AMRG strives to train rescue-level members to be proficient
rope riggers. Consistent with this goal, it is useful for rescue
members to understand a variety of hauling systems and how
to build them. This handout covers a variety of different
hauling systems and the forces at different points in the
systems under a 2KN load. There is a natural progression of
hauling systems. A simple 3:1 changes easily to a simple 5:1
which changes easily to a compound 9:1. The natural
progression of ganged systems is a simple 4:1 changing to a
compound 6:1 (3:1 onto a 2:1) changing to a complex 10:1
(complex 5:1 onto a 2:1). A 3:1 with a change of direction
naturally progresses to a complex 5:1 which has almost as
much pulling power downhill as a compound 9:1. Rescuerated members should be able to quickly convert from one
system to another in its natural progression.
Provided by Mark Miraglia using Rescue Rigger software.
10/20/2004