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New AAC Article on Anchors
Jim Titt wrote: Indeed but that may well be precisely why one needs to try and wring every last ounce of safety that can be wrung out of whatever anchor ends up being used |
anotherclimber wrote: There is no criticism of Marty, implied or otherwise, in my post. I apologize if it reads that way. If someone with decades of experience on obscure routes with marginal anchors were to ever post on here on how he and his partners got up those things I promise you it was not likely by any of these methods with any regularity, unless it is one of those "Mud Tower" psychos of the Southwest that have an unhealthy obsession with choss. Fundamentally their survival is done by not falling ie climbing ability, not that they are taking plops onto somehow equalized anchors that are otherwise marginal. No one "makes a living" doing this sort of thing for long. The relatively low number of deaths to catastrophic anchor failure is proof. Survival is done by not falling, or backing off before the fall occurs. People don't commonly get killed by bad anchors that fail without. They get killed by falling on them or by using bad judgment to use them...There is an important distinction there that I am trying to make, that is, you must have the skill to climb the route without falling before you remotely consider using a bad anchor. If you think you might fall above a bad anchor you need to be bailing, not climbing on. It is not the macrame that is going to keep you alive. It is actually finding and using bomber gear, or accepting that no one can fall and then not falling and/or taking a proper stance to bring up the second and recognizing that the whole party is free soloing until better gear is found etc or **maybe** equalizing a bunch of shit to rap and get back on the ground ie knowing when you have to back off. If your partner doesn't agree, insist, and get a new one. That's it. I am trying to emphasize that learning the very best method of stitching together shit is out of place until you are ready for Alpinism (which is some high percentage of free soloing while being tied into someone else doing the same) or after years or belaying off of bomber gear and you are ready to accept the risks of real adventure and your partner signs up too. (I am not criticizing you or anyone specifically. I am sharing 40 years of climbing experience, take what you can understand from it if you choose and leave the rest). :) |
jktinst wrote: A safe anchor is easy, by normal definition it´s two or more "good" pieces joined together in a redundant fashion (in case our judgement was faulty or whatever) and in a way that the force on the anchor is not unescessarily magnified if one of the pieces failed. You are talking about improving an unsafe anchor which will still fundamentally be unsafe. The decision then is between a method which increases the chances of the whole anchor withstanding the applied force but increases the chances of total failure if one or more pieces fail OR a system which reduces the chance of the entire anchor holding the applied force but reduces the chance of total failure if one or more pieces fails. you aren´t wringing every last ounce of safety out of the anchor, merely deciding on one of two equally undesirable options. The problem, as we know for last few decades, is that people may decide on one of the options on the basis it "improves safety" and transfer it to general anchor building where it definitively doesn´t, unwittingly actually building more dangerous anchors than if they followed more traditional principles. |
jktinst wrote: I don't agree. Your only safety will be in not loading it, not in believing that you are making it safer by some technique or other. Go aid climbing. Test bounce hundreds to thousands of placements. That is my perspective on anything that looks marginal and you simply don't know until they are tested. I get the sense that is the gulf in understanding here, and I am not trying to demean anyone. Jim nails it above: You simply cannot judge what method to use (only actually randomly choose from bad options). Rather than go down this path build many, many simple and strong anchors. GTFO of there and back on the ground otherwise is the only rational advice to give. |
Patrik wrote: Sorry. Long answer again. None of this lends itself to quick off-the-cuff replies. I started out discussing mangy bail anchors, then strayed into belay anchors in the paragraph you quote. I guess I'll continue with the broader focus in this answer. I don't want to downplay the issue of shock-load from blown-arm extension in dynamic anchors. However, I have not seen any test results showing how much shock load might realistically be caused by small extensions on multi-point climbing anchors with dynamic rope in play (note: blown-arm tests don't have to involve getting stuck with really tight extension-limiting knots at every replicate test. These tests could just as well be done by simply making the blown arm very short). In an anchor made of borderline pros (whether they are borderline for bailing, belaying the second or leading, in order of increasing expected strength), I believe that the primary objective is to share the load among the available pros as evenly as possible (or in a way that reflects the subjectively-perceived strengths of each pro, if there are obvious differences) in order to try and lower the risk of one or more pros popping. And this risk should be further lowered by either testing each pro prior to testing the whole anchor (when expecting a stronger anchor) or at least testing just the whole anchor prior to bailing from it. Of course, the partners must also know that they are very much in a "no falling" situation. Mitigating the risk of both shock-load and sequential failure in case one pro does pop comes as a secondary objective for me because if it does pop despite the testing, things get much hairier regardless of the system chosen to link the pros together. Sequential failure could come in multiple steps, if the whole remaining load shifts to each of the remaining pros one after the other; but it could also just as well come in a single step from too high a shock load even if it did get fairly evenly spread over the remaining pros. This is where we get in the realm of the subjective and arbitrary, as Jim said (and my thinking has evolved over time too so this is probably just the latest). I'm increasingly leaning towards using as much dynamic rope as possible: climber's rope, of course, and my partners and I always use dynamic tethers, but for these rare and scary situations, I'd also use thin dynamic rope for the anchor itself. The role that dynamic cordage can play in both improving the load-sharing capabilities of static anchors and minimizing shock-load in extension-limited dynamic anchors has been discussed and speculated about in the past but I have not seen tests measuring and comparing these two effects. So, my entirely subjective and arbitrary take on this is that, with as much dynamic rope as possible in play, I should not get significant shock loads from extensions of about 2-3 in. max. (more below on what leads me to make this assumption). If I can set up the anchor to maintain load-sharing in the event of a pro failing, without widening the extension much more than a couple of inches, I'll do that (ie by keeping the pros reasonably centered around the vertical axis of the central point). However, if I can't, I'd rather focus primarily on load-sharing and take the chance that, if a pro fails, a greater portion of the load will go to one of the remaining pros. In that situation, I also hope that the shifting of the central point as it slides to the extension limitation stop, combined with the use of dynamic rope will still achieve better secondary load-sharing than a static anchor would have (even if it too was made of dynamic rope). Of course, choosing among a bunch of equally poor pros to pick those that are more centered may not be an option. I would also definitely not avoid using a slightly-better-looking pro option just because it's not centered. That's about all I can say in answer to the question. The AAC article talks about potentially severe shock loads even with short extensions but provides no specifics, data or references. A lot of blown-arm tests seem to have been done on 100% static cordage for rescue applications and those do result in huge shock loads. The DAV did some fairly realistic blown-arm tests (among others) in a climbing gym. The belayer-weight was free-hanging off a dynamic tether connected to the central point of the static-webbing anchor on which the leader-weight took an FF2-type fall. When they tested the sliding X with no extension limitation, they reported an increase in overall load of 40%. This means that, when arresting the weight and acceleration of both the falling climber- and belayer-weights dropping the length of the whole blown arm, the single remaining point experienced 1.4 times "something". Since I don't read German, I've asked in the past if that "something" was i) the overall load that the same type of fall generated on the same type of sliding X anchor when it arrested only the leader-weight without blowing an arm; or ii) the load on the remaining arm in a static anchor blown-arm test. But I still don't know. In any case, this shock-load is certainly not trivial but it's not the 5-7 times seen in static-only blown-arm tests; and these DAV tests were a bit of a worst-case scenario for a climbing situation (hanging belay + no dynamic arrest + full-arm extension). In their Climbing Anchors book, Long&Gaines mentioned carrying out blown-arm tests (also among many others) on the extension-limited unequal arms equalette at Jim Ewing's facility, using fuses of different strengths. I have not tracked down all the criticisms that have been levelled at them regarding those tests but from what I gather, they focused mostly on the fact that they used an FF1 set-up and did not including a belayer-weight drop. I really don't know if scaling up to a higher fall factor would have changed their conclusions significantly. However, it seems to me that by not including a belayer-weight drop, their tests must have pretty realistically mimicked what happens when the belayer is not getting pulled off a good stance and into free-fall by a blown arm (thanks in good part to the shortened extension). Although they did not provide numerical results for these tests, they reported observing no load multiplication; ie the second point was subjected to the initial load minus what the blown-arm absorbed before blowing. These last two paragraphs (ie my take on those tests) are why I choose (again arbitrarily) to think that the use of extension limitations; of stancing and dynamic arrest (to cushion the initial impact and keep the CP centered, in addition to resisting getting thrown into freefall by the short extension of a blown arm); and of as much dynamic cordage as possible should effectively take care of the shock load issue. Of course only detailed reports on tests specifically designed for this (or at least the parts of this that can be standardized for testing) could confirm or invalidate this assumption. There's also often confusion and contradictions associated with taking a hanging belay as a "worst-case" scenario where stancing can play no significant role and the belayer would automatically freefall the length of the extension in case of a blown arm. In most cases people mean "2 solid bolts, belayer dangles close to the anchor, and leader takes an FF2". In this scenario, I'd be quite OK using a static belay anchor rigged for optimum load-sharing with zero extension. However, I would still apply one of the FF2-prevention options, as I do most of the time anyway. I'm pretty sure that the only situation where I would have the belayer hang from a dubious multi-pro anchor would be if he hung 3-4 (maybe 5) metres lower down because that was the only one of the FF2-prevention options that was possible at the time. |
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So to sum up:- You are guessing |
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This thread is getting long, and I haven't read it all, so this might have already been said. When belaying off a shit anchor: 1. use the rope. Yes, this might well be more dynamic, but the main thing is that it is quick and flexible. It allows you without compromise to get the best pieces however far away, or however many. I had a shit 8-piece belay just the other day. It would take forever and a day to rig an 8 piece belay with slings. You will be worried, very worried and you will want up and out ASAP. 2. don't load the belay. Forget guide mode. Unless the belay is a hanging one, you should be able to hold the second by bracing with your legs or bum. 3. keep the rope to the second tight, very tight 4. if the anchor is shit, and you fall off the lower bit of the next pitch, and the rock is vertical or overhanging you will FF2, as you won't have any pro that sticks (if there was good pro, you would have included it in the anchor; if not overhanging you will roll and bounce, absorbing much of the energy in the fall, hence not FF2). The anchor will rip. Any anchor that can take an FF2 is not a shit anchor. Hence you both die. Hence you really need to ask yourself, is this the level of game you want to be playing? This is one time a multi-mess of slings might be good - so you can rap to escape to your mate (prusik backup) and then to the ground and the pub. 5. Personal conclusion based or rigging a reasonable number of poor anchors over the years: rope for belaying; slings for rapping. (Note: slings are great for good anchors.) |
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Yes, your points have pretty much all been discussed already. If you could provide a photo of that 8-pro anchor, it should be good for another 4-5 pages of discussions. More if it was actually a mid-route anchor and you brought the second all the way up to it and then lead climbed above it. |
jktinst wrote: Yes, it was a mid-route anchor. And I did lead off above it. I don't have a photo of my anchor, but this video (by another team) is of the route and shows the entertaining nature of the rock. At around 4:15 or so he says exactly what I said to my second. The following images shows the rock up close (zoom in) - protection is by slinging chunks of the rock (image by Geoffers)  All good fun. |
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Interesting circumstances. Basically a 4-pitch, slowly rising traverse of a sea cliff with lots of pro options, hardly any of them any good. Obviously it's not just slinging blocks. You also get to insert pros in the cracks between the blocks! And I get the feeling that these blocks are all mostly held in place by salt incrustations! Bounce test any of them? It seems as though the comment at 4:15 was rather superfluous (ie, could that belay have really been significantly worse than the first one shown or than most of the progression pros up to that point?). In fact, isn't pretty much the whole thing a no-falling situation for both leader and second? Out of interest, in terms of bailing partway through, are there any possibilities of cutting straight up and out along the way or were the only choices to reverse the route, complete it, or find a ledge and call/wait for a rescue? |
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lol its amazing what people will do when all they have is choss or pebbles (Grit) to climb on (see Britain). |
King Tut wrote: Sad, but true. :) But when we get really upset because all our cliffs are so small, we do stuff like this: https://www.ukclimbing.com/news/item/69926/new_1278m_long_route_in_uk |
jktinst wrote: 1. the last but one belay is very poor, and because you can't give the second a tight rope (it is a traverse at that point), the forces higher. if they fall). The other belays are ok. 2. falling would not be sensible, the sea is rough, as is the rock and you would hit something on the way down. There is no way out. But the climbing is super easy. 3. Bailing up would be harder than finishing the route, as the route gets climbed a lot and is therefore kind of solid, the rest of the cliff is harder and far less solid. 4. No one is going to come and find you, but you might be able to wave to a passing fishing boat. But it really isn't a serious climb. It is a great deal of fun. Just best not to snap a hold...... |
David Coley wrote: This is wonderful, thanks! ;-) OLH I particularly liked the "no more than two miles from a tea shop" part! Great photos, too. |
David Coley wrote: Well, honestly, its a triumph of the human spirit to create a "Mt. Everest" out of a 40' crag, complete with extreme hazards etc like the best of Grit...But we are spoiled out here in CA, USA with such good rock and endless possibilities, I do tend to be a snob about it. :) |
