johndavidjr Posted October 5, 2004 Share Posted October 5, 2004 THis is an indispensible paper for engineers & rock climbers I picked up from gunks.com poster. It analysis "safe" run-outs. http://www.losalamos.org/climb/xRopes.pdf Quote Link to comment Share on other sites More sharing options...
ScottP Posted October 5, 2004 Share Posted October 5, 2004 Recommendations: • Build your anchors to withstand 25 kN (5500 lb) when possible. • If you are going to use wire chocks and cams that have a typical strength of 2000 lbs, then don’t lead out more than 1/4 the belayed rope length. • Never exceed your climbing abilities on a big wall climb. Test your skills at a rock gym, on bolted routes, or under top-roped conditions. • Use only ‘new’ ropes for lead climbing. To protect against shock loading of the anchors, use a rope with a low modulus or impact force rating. • Use a dynamic belay device. Quote Link to comment Share on other sites More sharing options...
RuMR Posted October 5, 2004 Share Posted October 5, 2004 yeah...only 'new' ropes...sure, right you betcha Quote Link to comment Share on other sites More sharing options...
Dru Posted October 5, 2004 Share Posted October 5, 2004 • Never exceed your climbing abilities on a big wall climb. Test your skills at a rock gym, on bolted routes, or under top-roped conditions.  they have big wall climbs in the Gunks? Quote Link to comment Share on other sites More sharing options...
Drederek Posted October 5, 2004 Share Posted October 5, 2004 What about the friction created by sliding down the rock on a slab? Not everything worth climbing is overhanging. What part of the rope takes the most strain? If you take 5 leader falls on the first bolt of Hot Monkey Love do you ruin the whole rope or just the end? (the answer is your belayers glasses) Sounds like a skinny stretchy rope may be the way to go. Quote Link to comment Share on other sites More sharing options...
Squid Posted October 5, 2004 Share Posted October 5, 2004 Recommendations:  • If you are going to use wire chocks and cams that have a typical strength of 2000 lbs, then don’t lead out more than 1/4 the belayed rope length.  ??  How am I supposed to leave the belay? Quote Link to comment Share on other sites More sharing options...
korup Posted October 5, 2004 Share Posted October 5, 2004  Where, oh where did they ask these people?  >These three experienced climbers fell to their deaths believing that the cam >type protection device could protect a fall of over 100ft without pulling out. >Many other experienced rock climbers that I interviewed also believed that >50 to 100 ft. lead outs were ‘safe’. Quote Link to comment Share on other sites More sharing options...
Alpinfox Posted October 5, 2004 Share Posted October 5, 2004 Recommendations:  • If you are going to use wire chocks and cams that have a typical strength of 2000 lbs, then don’t lead out more than 1/4 the belayed rope length.  ??  How am I supposed to leave the belay?  I dunno.... Ask Zeno . Quote Link to comment Share on other sites More sharing options...
Gary_Yngve Posted October 5, 2004 Share Posted October 5, 2004 Was Dean Potter the one who was filmed taking that big whipper while climbing some 5.13 sandstone route? Â Anyone know the fall factor and/or pro? Â My guess is that fall at least anecdotally contradicts the theory expressed in the paper (which I have not had time to read critically, and probably won't have the time for at least another week). Quote Link to comment Share on other sites More sharing options...
RuMR Posted October 5, 2004 Share Posted October 5, 2004 What about the friction created by sliding down the rock on a slab? Not everything worth climbing is overhanging. What part of the rope takes the most strain? If you take 5 leader falls on the first bolt of Hot Monkey Love do you ruin the whole rope or just the end? (the answer is your belayers glasses) Sounds like a skinny stretchy rope may be the way to go. Â what the fuck does this have to do w/ a new rope?? Â overhanging? friction? just what the hell are you talkin' about? Â sorry, but sometimes you post the dumbest shit Quote Link to comment Share on other sites More sharing options...
RuMR Posted October 5, 2004 Share Posted October 5, 2004 the paper, while it talked about slippage in belay devices, did not mention one important factor...that being the "give" in a belay (ie belaying from your harness so that your body gives a bit, or an unanchored belayer standing on the ground)...all of those generated impact forces quoted and the math behind them assume a boundary condition that has a fixed, static anchoring system...this can be mitigated in the "real world"... Quote Link to comment Share on other sites More sharing options...
iain Posted October 5, 2004 Share Posted October 5, 2004 I find climbing is most fun when I bring along a TI-85 to calculate the forces after each piece I place. Well, almost as fun as when I bring along my range finder to determine the precise distance to my last piece to determine how much pain I will be in when I fall. Quote Link to comment Share on other sites More sharing options...
RuMR Posted October 5, 2004 Share Posted October 5, 2004 HP > TI Â ya wank Quote Link to comment Share on other sites More sharing options...
Dechristo Posted October 5, 2004 Share Posted October 5, 2004 • Never exceed your climbing abilities on a big wall climb. Test your skills at a rock gym, on bolted routes, or under top-roped conditions.  Seems to me the climbing ability of most is not due to physical limitation, but mental condition. The mental factor of a climber is not conditioned FULLY to accept the expansion of their climbing ability until AFTER they LEAD what they have not led before.  This OSHA mentality of "not climbing beyond one's ability" smacks of product liability lawyers and those who have painfully succumbed to the manifold fruit and bondages of fear, for themselves and others. Without freedom of heart no one will do anything beyond their limitations; whether in their own minds or what others deem possible.  Quote Link to comment Share on other sites More sharing options...
Drederek Posted October 5, 2004 Share Posted October 5, 2004 overhanging? friction? just what the hell are you talkin' about? Climbing Quote Link to comment Share on other sites More sharing options...
Bug Posted October 5, 2004 Share Posted October 5, 2004 Always assume you are about to die. Never trust a little when you can place a lot. New stuff is better than old stuff. What is new in this paper? Quote Link to comment Share on other sites More sharing options...
Squid Posted October 6, 2004 Share Posted October 6, 2004 Seems to me the climbing ability of most is not due to physical limitation, but mental condition. The mental factor of a climber is not conditioned FULLY to accept the expansion of their climbing ability until AFTER they LEAD what they have not led before. This OSHA mentality of "not climbing beyond one's ability" smacks of product liability lawyers and those who have painfully succumbed to the manifold fruit and bondages of fear, for themselves and others. Without freedom of heart no one will do anything beyond their limitations; whether in their own minds or what others deem possible.   amen Quote Link to comment Share on other sites More sharing options...
ScottP Posted October 6, 2004 Share Posted October 6, 2004 (snip) What is new in this paper? Â The Newton force meter for anchors. Measurements for that 1/4 of the rope you shouldn't go beyond. Having a new rope each time you want to lead a route. Gym/bolted route prerequisites... Â When did over-analysis come into vogue? Do people really worry about this shit when they climb? Quote Link to comment Share on other sites More sharing options...
johndavidjr Posted October 6, 2004 Author Share Posted October 6, 2004 (edited) An unusual & confounding work of science. Here is Los Alamos Mountaineeing Club's somewhat morbid intro to member-article: "Stephen W. Attaway has produced a very complete mathematical analysis of rope systems used in rock climbing. This article was published in Nylon Highway, No. 41, a Special Publication of the Vertical Section of the National Speleological Society, and in the preceedings of the NATARS meeting of November 1-3, 1996 in Las Vegas, Nevada. This work is dedicated to Dr. Carlos Abad, Dr. Jane Tennessen, and Dr. Glen Tietjen who died from a fall in the Sandia's of 817 feet on June 23, 1996. http://www.losalamos.org/climb/zDWNLOAD.html --Dangerfield  Edited October 6, 2004 by johndavidjr Quote Link to comment Share on other sites More sharing options...
ashw_justin Posted October 6, 2004 Share Posted October 6, 2004 Black Diamond's answer to Metolius Range Finder Cams. The Graphalot-85. Â Quote Link to comment Share on other sites More sharing options...
cracked Posted October 6, 2004 Share Posted October 6, 2004 I'm on the floor here. Quote Link to comment Share on other sites More sharing options...
RuMR Posted October 6, 2004 Share Posted October 6, 2004 Black Diamond's answer to Metolius Range Finder Cams. The Graphalot-85.  post of the year goes to justin... Quote Link to comment Share on other sites More sharing options...
rbw1966 Posted October 6, 2004 Share Posted October 6, 2004 Beautiful work! Quote Link to comment Share on other sites More sharing options...
billcoe Posted October 6, 2004 Share Posted October 6, 2004 Beautiful work! Â Can you direct us to the purchase location for those beauties? Quote Link to comment Share on other sites More sharing options...
Geek_the_Greek Posted October 6, 2004 Share Posted October 6, 2004 IMO: Â The article actually does have some interesting points. Overall, though, I was struck with the impression that a little knowledge can be a dangerous thing.... Â -wrong use of climbing terminology struck me throughout and set off "gumby alert" alarm bells in my mind (e.g. referring to multi-pitch as "big-wall", individual pieces of pro as "anchors", referring to runout as "lead out", etc.) Â -no evidence that the three people who were killed, thus serving as a supposed example for the study, fell because of broken pieces of pro (it sounds like the pro pulled out to me, rather than broke - a vastly more common occurrence) Â -some very important points missing from the analysis (e.g. "I am not sure how friction from a zig-zag rope system would affect the analysis" p.9-10; here he is referring to the rope going through more than one piece of pro, and thereby more than one 'biner, each adding friction; another example is treating the belayer/anchor system as totally static, or rigidly fixed to the wall - we all know this to be false, and probably one of the biggest reasons why hard falls are never as serious as they should be (based on calculations). I'm talking about the belayer's body being yanked around on a big fall and the like). Â Â Â This stuff doesn't totally undermine the conclusions, but just reinforces that the engineering calculations for this stuff produce a conservative estimate. This is a good thing. The fact is that for people who are hurt while climbing, very very rarely is it from properly rigged gear failing (no, I'm not talking about open-gate or cross-loaded 'biners or pro pulling out), so it's often moot, in my opinion. But for those who continue to be terrified that they will be killed because of their gear breaking, the article has some good points. It's certainly true that you can expect to be hurt if you take a true fall with FF>1. Quote Link to comment Share on other sites More sharing options...
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