Dr_Crash Posted April 12, 2004 Posted April 12, 2004 Hi, I'm learning how to do glacier travel as part of doing ski mountaineering, and have a question about clipping into the rope. We clip in because we're wearing heavy packs and want to leave those hanging on the rope when we're climbing out of a crevasse. The textbook I've been using, "Glaciers! Travel and Rescue" by Strong, shows clipping with a single locking carabiner. But every Petzl carabiner (or harness) notice that talks about clipping in says you need to use two carabiners with the gates facing opposite directions, or you risk that the rope would load and break the gate during a fall. The Petzl "Experience" brochure has some diagrams of that deadly sequence too. What is your experience? Is the double carabiner warranted for glacier travel, or are the loads in play unlikely to enable the gate-breaking scenario? Thanks in advance, drC Quote
iain Posted April 12, 2004 Posted April 12, 2004 A single locking carabiner is widely considered perfectly adequate for glacier travel. Quote
catbirdseat Posted April 12, 2004 Posted April 12, 2004 (edited) If you don't like the gate-breaking scenario, don't use a carabiner at all. If you are on the end use a rewoven figure eight. If you are in the middle, tie in with a double bowline. To make absolutely certain the knot doesn't come untied, clip the tail loop of the double bowline to a gear loop or leg loop on your harness using a biner. Edited April 12, 2004 by catbirdseat Quote
miller Posted April 12, 2004 Posted April 12, 2004 a single carabiner is widely considered to be adequate for glacier travel, but its not. there have been accidents where they break. i would strongly recommend using two biners, one locking and one non-locking as a backup, with the gates in the SAME direction. i personally dont like the big pear type biners because they tend to flip around a lot more easily. i would recommend a combo like a locking BD enduro with a BD hotwire - they fit well together. you dont want a combo of biners that are mismatched in size because the smaller one can sometimes flip through the big one and create some funky crossloading if weighted. be sure to clip into the belay loop too - if your harness doesnt have one, tie one on with about four wraps of spectra and a double fishermans. also, some people skip the biner clip in and tie in on the rope. you can do this with a fishermans - tie a large bight with an overhand (to keep the actual tie in from getting crossloaded) then tie a regular overhand knot, take the remaining bight and tuck it through the overhand knot and tie another overhand around the rope on the other side. the two knots tighten against each other and are solid. i dont like this system because of escape/rescue inefficiency, but some do. hope that helped! Quote
Rodchester Posted April 12, 2004 Posted April 12, 2004 A single locking carabiner is widely considered perfectly adequate for glacier travel. I generally agree with iain. In most situations here in the PNW, I feel that a single locker is sufficient. However, Petzl is correct that a single carabiner can have some problems in some scenarios. Quote
Dru Posted April 12, 2004 Posted April 12, 2004 a 3/8" stock, stainless steel maillon rapide/quicklink from a climbing anchor company like Fixe is better to use than a single biner on account of the long, narrow shape is much harder to crossload in practice than a pear biner. Don't just buy one from the hardware store because the climbing anchor ones are actually 3-sigma tested and meet CEN and all that. I use one of these for my TR self-belay after finding my pear biner consistently crossloaded while climbing. Quote
iain Posted April 12, 2004 Posted April 12, 2004 I like dru's solution. If you feel you could exceed minor axis on a glacier fall perfectly on the gate (usually around 7kN), the rapide makes some sense. This seems unlikely in snow-covered glacier country where you would be roped, but you're wearing a big pack, a lot of gear, big crevasses, slack, who knows. Better safe than sorry I suppose. Quote
Stephen_Ramsey Posted April 12, 2004 Posted April 12, 2004 a single carabiner is widely considered to be adequate for glacier travel, but its not. there have been accidents where they break. Miller, I'm very interested in this. Could you provide a source? Not doubting your information, just looking to read more. Maybe there are examples of this happening, in the ANAM? -Steve Quote
Dr_Crash Posted April 12, 2004 Author Posted April 12, 2004 i would strongly recommend using two biners, one locking and one non-locking as a backup, with the gates in the SAME direction. Why in the SAME direction? Ease of use? I thought Petzl's goal in having the gates face opposite directions was to ensure that at least one biner would be loaded in the body and not the gate. Fair point re: tying eliminating the risk of gate breaking, but I don't think it'd be easy to break open one of those double eights after a fall on it, while you're hanging on the rope. A bowline might be easier though. drC Quote
miller Posted April 12, 2004 Posted April 12, 2004 hey steve, unfortunately i cannot provide any written documentation of this and wouldnt know where to look - im sure its out there somewhere if youre really curious... i got this information from someone whos opinion i respect very much, and he is the technical director for the AMGA and a UIAGM guide - i.e. he knows far more than me and like a good subject, i do whatever master says. however, he seemed to be aware of specific cases and also some testing that had been done. im not sure if ENSA publishes their test results/case studies (and if they do whether or not they are available in english!), but if they do that might be the place to look. it didnt take much convincing for me - just think about how many times youve been out tromping around on a glacier and had to adjust your biner to the correct position. if its crossloaded and the gate is loaded, there can definitely be enough force in a crevasse fall to cause the biner to fail. also, the moral of masters lesson seemed to be that two biners greatly decreases this risk, but does not eliminate it. i guess the only way to be 99% certain that your attachment to the rope would not be compromised in a crevasse fall would be to tie in directly. Quote
miller Posted April 12, 2004 Posted April 12, 2004 word. ive had the same problem solo toproping. unable to find a steel biner at the time, i got one of those biners sold with the plastic thingy to keep it from flipping around and added a bunch of wraps of tape around the top of the spine so that my device cant creep down the spine. Quote
miller Posted April 12, 2004 Posted April 12, 2004 i would strongly recommend using two biners, one locking and one non-locking as a backup, with the gates in the SAME direction. Why in the SAME direction? Ease of use? I thought Petzl's goal in having the gates face opposite directions was to ensure that at least one biner would be loaded in the body and not the gate. Fair point re: tying eliminating the risk of gate breaking, but I don't think it'd be easy to break open one of those double eights after a fall on it, while you're hanging on the rope. A bowline might be easier though. drC yup, ease of use. Quote
JoshK Posted April 17, 2004 Posted April 17, 2004 I use 6 or 7 different biners to clip in, all from different major brands. You can *never* be too safe... Quote
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