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Climbing Information:
The Lab:
*Ascender* testing on ropes:
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clintcummins
Apr 23, 2009, 1:23 AM
Views: 6424
Registered: Nov 1, 2002
Posts: 135
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The October 2008 fatality in Zion (James Welton) was unusual for several reasons. He was using Petzl ascenders to ascend a 9.5mm static rope which was weighted below with haul bag(s). The rope was partly secured at the anchor above with a Petzl ProTraxion hauling pulley. Apparently the hauling pulley was not fully closed and the load caused it to open further and 20' or so of rope slipped through suddenly. This caused the haul bag(s) and Welton to drop 20', at which point the ascender(s) reloaded the rope, damaging the sheath to the point of failure. The core then failed as well and the rope broke.
I doubt that changing the type of ascenders or diameter of the rope would change the outcome of this accident (but I could be wrong). Having no haulbag weighting the rope, or a dynamic haul rope might make a difference. But most important is to have the fixed rope you are ascending be properly anchored.
You could test ascenders and ropes to see if they would sever the rope in a more likely situation, such as if a person is cleaning an aid pitch (ascending a dynamic lead rope), and some protection above them fails where the rope makes a turn (such as on a traverse). Say they fall 20' on 80' of rope and they weigh 180 pounds - does the rope get severed?
A second situation where ascenders could be loaded heavily is if you have taken an aid climbing leader fall, and are using ascenders to regain your high point. In the process, if your highest piece of protection fails, you take a leader fall, and it might be long if more protection fails sequentially. In this situation, Pete Zabrok recommends using a GriGri to ascend the rope, because it loads the rope over a larger surface. (In general, ascending with a GriGri is slow, but it may be advised in this situation where a second leader fall is somewhat likely).
In some posts to this thread, they mention Jumars very casually, which might be taken to mean that Jumar brand ascenders were used in the 10/2008 fatality. They were not. You should be careful to use "ascender" instead, unless you have a particular brand in mind. In Majid's second post, he recognizes that Gibbs ascenders impact the rope differently than Jumars (and by implication, other ascenders differ as well).
Links for the 10/2008 Zion accident:
http://www.supertopo.com/...html?topic_id=808440
http://www.supertopo.com/..._id=701629&tn=40
(This post was edited by clintcummins on Apr 23, 2009, 1:33 AM)
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