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Re: [r0cker] Cordelette Strengths:
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ryanb
Jul 17, 2008, 4:31 PM
Views: 8915
Registered: Nov 4, 2004
Posts: 832
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I've moved away from the cordelette recently in favor of the climbing rope but I did a long alpine free route with predominately hanging gear belays sunday and my partner, a former guide, brought two skinny cordelette's which worked great to reduce the cluster fuck at belays. Yesterday, to kill time at work, I was doing some research/calculations about how skinny you could go. Found this site: http://www.caves.org/.../49/cthsc/cthsc.html Summery: 7mm nylon cord rated for ~11 kn does not weaken with flex cycle testing and has strength reduced only %8 at knot. Ends up with a cordelette strength around 22 kn (for each leg). High strength cords weaken tons with knots and flexing and end up with lower cordelette strengths as low as 11 kn for sterling vectran which i believe is no longer sold. So 7mm is more than sufficient and we can interpolate some of the newer 6mm nylon (mammut pro cord fro example) rated as high as 7.8 kn will have a ultimate strength in cordelette formation of 14-16kn per leg which is about what most of my pro is rated for. This is consistent with the AMGA's recommendation (http://www.amga.com/.../gearlist_alpine.php): "Cordelettes — Bring 2 or 3. Cordelettes are 5–6 meters of 6mm or 7mm pure nylon cord. Tech cords are not as helpful for rescue work and hitches." Thoughts? IS 6 mm nylon to skinny for a cordelette? 7 mm is definitely best for TR etc when weight and bulk matter less.
(This post was edited by ryanb on Jul 17, 2008, 4:32 PM)
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Edit Log:
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Post edited by ryanb
() on Jul 17, 2008, 4:32 PM
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Post edited by ryanb
() on Jul 17, 2008, 4:32 PM
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