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A More Efficient 3:1 Pulley System
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Tip/Trick/Gimmick: A More Efficient 3:1 Pulley System ? Source: Ontario Rock Climbing Association - Safety Manual Contributed by: Marty Comiskey ( martycomiskey@yahoo.com) Best useful for: Top rope Trad x Mountaineering x Description (limit to 200 words): At the recent "Leader's SKill Day" at Carderock, Md. on 4/10/10 we showed PATC members how to construct a 3:1 pulley system in the event they needed to help/aid a stuck "second" having trouble on the crux. With any system there are pros and cons. Using the relatively simple to set up "3:1 'Z' Pulley System" here are some of its advantages and disadvantages:
Cons - lots of friction at Reverso/BD Mountain Guide ATC/belay device At "Leader's Skill Day" I briefly demonstrated an alternative pulley system that some found interesting (and I promised participants I would send out this write up). I found this pulley system in the "Ontario Rock Climbing Association - Safety Manual." They called it an "Inverted Piggyback Pulley System." It is a variation of the Spanish Burton pulley system. The Inverted Piggyback system's advantages include: Disadvantages include: The Inverted Piggyback system can be set up using a seperate length of cord (i.e. cordalette) or a section of the climbing rope. As one pulls down on the Inverted Piggyback pulley system, slack will develop in the climbing rope at the Reverso. This slack must be pulled through the Reverso while holding the pulley line tight to assure proper belay of "second." This is a bit cumbersome, but more than worth it for the improved efficiency of the pulley system. I have included a diagram from the Ontario Safety Manual showing this set up. Take note that this book was written (~ 1990) before the invention of the Reverso and their diagram shows an old style locking belay rig.
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