Do you use the Sliding X for equalizing two pieces of protection?
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I use the sliding x sometimes and most of my partners use it as well. Once in a while I will tie off one strand to prevent excessive extension. |
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Back-in-the-day (R), I used the sliding X to equalize opposing nut placements all the time. It's a very easy equalization technique to do with one hand. I rarely make opposing nut placements these days with all the new-fangledy thin camming protection I have. But I still use it extensively to equalize pieces in an anchor. I was aware of the "shock loading" issue, but it never seemed reason to avoid using it. I'd like to see some test data before concluding that this is the "death X." Really? If all the stuff they say is dangerous were really that dangerous, I'd be dead by now. |
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I use a sliding X when putting up top ropes for multiple climbers on sport routes. Based on the link - is this a bad idea? |
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The linked article cites "too much extension," which I assume is the feared shock loading from the failed side of the X disappearing while the other loop doubles in length. Like NSFOD, I've heard that's the danger, but that's always seemed odd. Severe shock load from dropping an additional foot or so? Not ideal, but hardly the stuff of massive acceleration force. Are the physics more complex than that, or is the criticism just hyper-cautious? |
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Yes, after reading the article, it seemed unclear...I am assuming a lead fall would generate enough force to render a system failure...I rarely use a sliding x while leading, but when I do it usually links to less ideal pieces into a greater system? |
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There were studies/testing done in the course of his recent anchors book update that led John Long to do some major rethinking of the issues of equalization and of shock load on extension. A huge amount of discussion on the subject took place on climbing message boards, but the upshot is that he discovered failure of one piece in a sliding-x anchor causes negligible shock loading on the remaining piece. |
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The biggest problem with the picture in the article is that there are no knots where the sling attaches to the two pieces of gear. In its current state, if the sling were to break, then the whole anchor fails. However if you tie a figure eight or equivalent right near the two anchors, you now have two independent strands for the lower carabiner. |
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Interesting, since I have never seen or heard anyone refer to that "Camp 4" site? Also the sliding X is the AMGA certified way to set up top ropes from bolted anchors. I have never used the sliding X on anything other than bolted anchors or to equalize 2 mediocre pieces while leading. I've always used the cordalette system to equalize a 3 piece anchor. |
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The Sliding X is not safe at all. |
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Climbers have been using the sliding knot for a long time, and the potential for shock-loading when using this method is not news. John Long discusses it at length in his "Climbing Anchors" series, (a must-read for aspiring leaders) though he calls it a sliding knot. His sequel "More Climbing Anchors" goes further into the downfalls of the sliding X and makes similar recommmendations regarding it's use. |
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This is a very good point and why I never build my entire anchor around a sliding X linking every piece. I also tie my rope into selected pieces usually too. But, the goal is to never be completely reliant on one piece of gear. |
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I have become accustomed to rigging the equalette with the "sliding X" between the two limiter knots that make up the master tie-in point. |
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James DeRoussel wrote:My main gripe with the sliding X is not only the potential for shockloading, but the complete lack of redundancy. With a sliding X, you are relying on one piece of webbing. There is zero redundancy there. This makes it a poor choice for anything other than the scenarios above, where they are part of a larger system.There is an ugly, bulky solution for redundancy: I've used two slings to make the X. FWIT, I've never used sliding X's except for belay anchors. |
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camp4.com/rock/index.php?ne…
This article is both scary and funny. The claims made in this article are blown way out of proportion. From the article: ---------------------------------------------------------------------- "While the sliding X does equalize the pieces, it assumes that neither could break, since if one does break, there is severe extension in the system - enough that it would likely cause the carabiners to break. Since it assumes neither piece would break, it's a stupid system - if neither would break, there's no need for equalization. If one might break, then there is WAY too much extension. This is why many call it the 'death X.' Instead, use one sling off of each bolt or piece. You can tie one shorter to approximately equalize the pieces if needed." ---------------------------------------------------------------------- I have _never_ heard this called the "death x". True, climbers like to nick-name things with the word death (American-Death Triangle, European-Death Knot) but this is a new one to me. I have fallen on enough gear/bolts/'biners to know, for an absolute fact, that it is practically impossible to break a 'biner on a TR. Slings, 'biners, ropes, etc. are all built to hold lead falls, including the dreaded Factor 2 fall. By definition, a TR fall is going to have LOTS of rope involved and will be a fall factor well below 1, which means it is a soft fall and will not stress the carabiner. Unlike the mis-informed author on Camp4, when I use a Sliding X, I am building it because I do think it is possible (although highly unlikely) that an anchor could potentially fail. The Sliding X is a useful skill for any one rigging a TR and I use it from time to time while leading. That being said, it should only be used by someone who knows what they are doing and knows when it is an appropriate technique and when it is not. The author of the comment/post on Camp4 is clearly not well educated about the uses and benefits of this technique and based on their preferred technique; I for one would prefer to never climb on one of their anchors. P.S. - I do not recommend building an anchor composed of a single Sliding X. In an anchor, everything should have some form of back-up / redundancy. When using a Sliding X I always include at least 1 bomber piece of gear that is completely independent of the Sliding X. This helps prevent the allegedly dreaded accidental extension AND provides redundancy to the webbing used for the Sliding X. If you only use 1 Sliding X and that piece of webbing fails (highly unlikely) it would result in the complete failure of the anchor. Conversely I have seen 4 piece anchors using two sliding x's and I consider this to be an equally good alternative. Cordelettes/Web-olettes which are tied off have the advantage of having that same redundancy built in but lack the other advantages of the sliding x. |
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I just noticed that the information posted on Camp4 was resourced/republished from the ASCA website which surprised me. |
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Not So Famous Old Dude wrote:...the goal is to never be completely reliant on one piece of gear. Except, of course, when belaying or rapelling, then I'm just okey-dokey with putting it all on the line with one big locker or one belay device. What is THAT all about???? We all fret over redundancy, but then it seems like everyone always just implicitly trusts that one biner on their harness or that one belay loop.Good point, I suppose if we were really going to go all the way with redundancy, we would use two biners on rappel plus an additional piece of webbing run through our harness to mimic and back-up our belay loop. THEN we would be redundant... |
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I find this interesting because I used to use the sliding X all the time on double bolted belays, before I heard the same things from some partners. Frequently I'd back up one leg with something static just in case one bolt blew - you were still doubled (at least webbing/carabiners). I think now I feel more comfortable with separate draws/runners for TR as everything is doubled - 2 bolts, 2 slings, 2 biners. |
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Paul Hunnicutt wrote:Should we go back to rappiing/belaying through leg and waist loops? That would really suck if your waist loop blew and you are hanging from leg loops, but better than nothing I guess.Actually, I still use an old BD Bod harness for freeclimbing - the ones without the belay/rappel loop. I will probably be replacing that soon, though. I expect that I will still continue to put my locker through both legs and waist, though, regardless of what type of harness I buy. I just can't get over the idea of a belay loop looking too wimpy. I know that's all in my head (unless frayed a la poor Todd Skinner), but I probably will only use the belay loop as an optional clip in point from time to time (which would definitely be useful). |
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I have a climbing partner who ALWAYS wears his Metolius Personal Anchor System when we are multi-pitching. Of course, his PAS is girth-hitched onto-his harness through BOTH his leg loops and his waist. He (short) clips his PAS into the locking biner that is connected to the rope/ATC when rappelling. This effectively backs up his belay loop while he is rappelling. |
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I posted a somewhat lengthy reply to Mal's post on Super Topo. Rather than cross-post it here, the reference, if anyone is interested, is |
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"Also the sliding X is the AMGA certified way to set up top ropes from bolted anchors." |