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Post by dougsanders on Mar 3, 2014 6:14:47 GMT -8
The Carabiner Brake (CB) is used for rare events: a substitute for rap device and, when 2 are linked, lowering a 2 person load; however, there are more simpler, faster, alternatives.
Historically, I suspect the CB was the first rappel device. (OK, maybe it was a spiral wrap around the carabiner spine.) It was simple, smooth and easy to build. That was when all biners were large ovals. As carabiners evolved away from ovals the CB has become harder and harder to build. Today, if we did not know anything about the CB and someone presented the technique to us, I think we would roll our eyes and point out that it was hopelessly complex, time consuming, hard to learn, perishable skill and has failure modes.
At one time the Figure 8 was the most popular belay and rappel device. Compared to newer devices, the Figure 8's weight and characteristic rope twisting were an evolutionary dead end.
In F8 there are are nearly 2 pages devoted to these 2 techniques.
Assuming F9 will be in book format primarily for educating Basic and Intermediate climbers, this is not the best use of space. Both of these techniques should be de-emphasized or eliminated. Additionally, to the new climber trying to learn one of the sport's riskiest practices, their inclusion in the text is extraneous.
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Post by gregggagliardi on Mar 3, 2014 13:20:07 GMT -8
Possibly move figure 8 rappel device to the chapter on expedition climbing. Here is a nice summary on various belay device and their best uses. The AMGA includes it their course manuals. www.thebmc.co.uk/belay-devices
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Post by kensmall on Mar 29, 2014 9:23:38 GMT -8
So far as I know, the original rappel device was the brake bar (what you will find in equipment catalogues are fancy devices used, I guess, for caving and rescue). This was a dazzlingly fast and efficient method of rappelling but allegedly dangerous because of the stress it put on the hinge. I'll accept that it was dangerous, though I never heard of any accidents using it. I can't agree with what you say about the CB. When it was introduced in Seattle ('78 if I recall), students didn't find it particularly hard to learn or complex. It is still taught in some branches. Inefficient? With the right choice of 'biners (perhaps most people now do not carry them) it is quite efficient and I'm not sure where the failure modes are. On multiple rappels I can make the transition in about 45 seconds. The best choice, in my opinion, is two BD light D's (or equivalent) for the reversed-opposed 'biners and either a BD standard oval or -- perhaps better -- a wire-gate oval. The additional weight over using only Neutrinos is fairly trivial. For the last 20 years or so I've been using both the CB and a belay/rappel device and will probably be going back to the CB now that I've replaced my suspect 35-year-old Chouinard light D's with BD's. A disadvantage I've noticed occasionally is that the CB can twist the rope, a problem I don't recall having when I was using Alpine Bod harnesses or other harnesses that leave the natural plane of the reversed-opposed 'biners oriented horizontally. If that's the reason, the adjustment is obvious. I intend to experiment.
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