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Self-equalizing vs. static anchor
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 Mar 30, 2011 So I am weighing the pros and cons of a self equalizing anchor system (like the sliding X or ACR) vs. a static anchor (Coordilett equalized, then tied off.) The self equalizing self equalizes but if one pice blows it will shock load the others. In the static system if one piece blows it does not shockload the others but the equalization is far from perfect. Thoughts? J macFrom Boulder, COJoined Oct 8, 200815 points
 Mar 30, 2011 anchors 101: SRENE Solid Redundant Equalized NO EXTENSIONS my \$.02 edit: i guess it also matters on whether you're talking about trad protection or bolts. and whether you're going to just be top roping from the anchor or leading up another pitch above it. T.L. KushnerJoined May 21, 20090 points
 Mar 30, 2011 I'm curious why you say a 'static' system can't be equalized? kpboFrom Fort Collins, COJoined May 25, 20080 points
 Mar 30, 2011 My opinion is as follows: like everything else in trad climbing, the answer is "it depends". Both are advantageous in certain scenarios so learn them both and figure out when you like using them. If you have two straight up and down pitches, tying off the anchor so it's equalized in one direction is fine, can be easier to deal with, and won't move if one piece fails. If the next pitch wanders, or heads off in a different direction than the last one finished in, a sliding x is probably your bet. If you are worried about "shocking" the anchor in case a piece fails, tie extension-limiting knots. What I mean is, if you have a 3 point anchor and one or all of the pieces is far away from the master point, then tie an overhand in the loop of rope that leads to those pieces. That way, if said piece blows, you only introduce a fraction of the slack into the anchor. of note in this situation is that you can only "slide" as far as your knots will allow, but take that into account when you're building the anchor and deciding where to tie the knots, and it will rarely be an issue. As long as you understand the limitations of both and how to apply them safely, then it really becomes a personal preference issue in many cases. One last thought: it is worth buying and reading "rock climbing anchors" by Craig Luebben (or any of book published by the mountaineers, for that matter). It's a great book that presents a lot of information in a very accessible way. have fun Dave Dave AlieFrom Golden, COJoined Feb 25, 201030 points
 Mar 30, 2011 I couldn't have said it better than Dave. Including the book recommendation! I would only use a sliding X if the pitch wandered back and forth a lot. Otherwise, equalize and tie a knot. Gif ZafredFrom Pittsburgh, PAJoined Nov 30, 20100 points
 Mar 30, 2011 The solid rock & solid pro using good angles are the critical parts. The rigging method is trying to match your intended direction of travel to load distribution off of multiple points. You're not getting perfect equalization in any case and you're not working for redundancy. However with the dynamic rope, you won't see anything high enough nor will you get "shockloading". Ultimately, your rope will fail before a solid anchor will. If the anchor failed, the pro wasn't solid and/or had exaggerated angles. Buff JohnsonJoined Dec 19, 2005545 points
 Mar 30, 2011 With correctly tied limiter knots, extension is not much of a problem. To obtain a full 360 degree circle of use from two points, limiter knots should not be any further apart than the distance between the two points of protection, any extra serves no purpose. They should also be centred about the midpoint between the two points. With this method, the maximum extension you can ever get is the distance between the two points of protection (for a sideways pull), and the more probable extension is half that distance (for a downwards or upwards pull). So for a typical bolted anchor which might be two bolts spaced 2 feet apart. You shouldn't ever be looking at more than 1 ft of possible extension. It also helps to tie the knots so that one strand of your x is slightly shorter than the other. This lets the midpoint slide more easily I find because the strands don't bunch up against each other. DannyUncannyFrom VancouverJoined Aug 27, 20105 points
 Mar 30, 2011 jmac wrote:So I am weighing the pros and cons of a self equalizing anchor system (like the sliding X or ACR) vs. a static anchor (Coordilett equalized, then tied off.) The self equalizing self equalizes but if one pice blows it will shock load the others. In the static system if one piece blows it does not shockload the others but the equalization is far from perfect. Thoughts? Thoughts? Here's mine... This subject has been hashed, rehashed, sussed, tied and put out to pasture on every climbing website on the interwebz. Not to mention the myriad collection of books available that answers this question directly. Searching MP alone will give you so many results you'll need an assistant to sort through them all. If that doesn't satisfy your lust for anchor info then I might suggest finding a mentor who can teach you hands on. Based on the terminology you use it would appear that you need to go back to the basics and try to forget some things that you have "learned". I agree with Mark Nelson. Good pro in good rock with good angles. That's all you need to know. Shock loading is a myth that doesn't make sense once you actually do the research and look at the forces involved. Big bomber gear in good rock isn't gonna fail no matter how you lash them together. Placing three pieces and cloving them all together nice and tight is perfectly acceptable as long as they are solid placements in solid rock. Attempts to equalize are good but in the end, six shitty placements all perfectly equalized and set for direction of pull are not as good as clove hitching your rope to a couple of big stoppers in bomber constrictions. Dicking around with complex anchor matrix's for hours on end at the belay is a great way to make it difficult to find a belayer as well. Not to say that the information you've been given and the graphs aren't loaded with good data (because they are and I appreciate them being posted) but it's all a bunch of theoretical number crunching that means nothing if you've got good pro in good rock with good angles. If you don't know what this means then you should borrow/buy John Longs "Climbing Anchors" and read it 3 or 4 times. All will be clear. And just use the rope unless you're leading every pitch. As somebody else on MP stated a while ago "It's the strongest, most abrasion resistant and dynamic piece of gear you have with you. Why wouldn't you use it?" YarpJoined Jan 16, 20110 points
 Mar 30, 2011 equalette rather than cordolette. The testing results near the end of Long's book shows significant advantages. The equalette also provides more lattitude in terms of equalizing falls where the load isn't perfectly aligned with the expected direction of fall (when setting the anchor). Dan HallJoined Jun 15, 20100 points
 AdministratorMar 30, 2011 I second what Yarp said, except buy Luebben's book and read it 3 or 4 times. Matthew FienupFrom Ventura, CAJoined Feb 18, 20066,283 points
 Mar 30, 2011 Pesterfield's book was pretty good too. Many, many others out there. Reading them all would be the best advice if you don't have anyone to help you out as you learn. YarpJoined Jan 16, 20110 points
 Mar 31, 2011 Buy both the Gaines/Long 2nd ed Anchors AND Leubben's Anchors books. They both cover things the other one does not or only touches upon. Gaines/Long has test results via Sterling on anchor loading and "shock" loading. I like Leubben for the clarity of images and more up to date equipment. Gaines/Long covers REAL anchor "philosophy" better. SERNE is kind of a "myth" in many ways. Both are worth the read. mattmFrom TXJoined Jun 2, 2006550 points
 Mar 31, 2011 SRENE is an oxymoron. You can never have full equalization without facing some extension. Period. A better goal is SRELE. Simple Redundant (massively misunderstood by the community) Equalized LITTLE Extension Sliding-X: Equalized, simple. NOT redundant (single cut failure mode on the sling) unless you tie limiter knots, or clove hitches at the pieces. NOT low extension unless you have a short sling or tie limiter knots (which limit the range of equalization). I still would knot kill my partner if her used a single good sling on a double bolt anchor, but I personally double them up the slings on the rare occasions I have used them. Cordalette: Lots of discussion on these is already overkill. Very limited equalization, little to no extension, good redundancy (you can cut any 2 cords or pull 2 pieces of gear before failure). With good gear and mostly straight up and down routes it is still a very good solution for many anchor situations. Equallete: Hybrid sliding X that trades a little extension for a region of equalization. Each half is statically equalized with a sliding-X in the middle equalizing those dynamically. The region of equalization is limited, especially on big-walls where you may need the anchor to hold horizontal loads as your partner cleans the last pitch, yet still be bomber for vertical loads once you start the next pitch. ACR/Trango Equalizer: Equalization, but NO redundancy to cutting of the sling/cord. Extension is possible unless you use limiter knots. ACR/Trango Equalizer with Clove Hitches on each piece: Slight reduction is equalization (50% max load vs. 33% without clove hitches), but you immediately get Low extension, and double redundancy (handles 2 cuts and/or 2 pieces blowing, though the extension can be large if two pieces blow). Rope cloved in: Can be statically equalizied (i.e. 0-100% load on each piece depending on millimeters of error on the knot locations). Zero redundancy for cut rope (we accept this at all times when climbing with single ropes), but as much redundancy as you have extra pieces in. Works well with vertical cracks, poorly for horizontal (greatly effects extension and equalization). Summary: Learn lots of methods, especially the underlying strengths/weaknesses. Approach each anchor with a keen eye towards would could go wrong and be prepared to modify your usual approach to assure that every anchor you make will keep you and your partner off the deck. MoofFrom Portland, ORJoined Dec 11, 20070 points
 Mar 31, 2011 Moof wrote: Rope cloved in: Can be statically equalizied (i.e. 0-100% load on each piece depending on millimeters of error on the knot locations). Zero redundancy for cut rope (we accept this at all times when climbing with single ropes), but as much redundancy as you have extra pieces in. Works well with vertical cracks, poorly for horizontal (greatly effects extension and equalization). For this I would add the equalizing figure 8 with the rope. For the equalette, the master point direction can be changed by adjusting the cloves. Rick BlairFrom DenverJoined Oct 16, 2007163 points
 Mar 31, 2011 Also the clove hitch master point is a good one. Clove yourself to a piece, clove the rope to another piece, clove your master point in between the two pieces. You can slide the knots around to whatever length you need, but it is still redundant. You can add more cloves, but you can only equalize two of them unless you make things more complicated. DannyUncannyFrom VancouverJoined Aug 27, 20105 points
 Mar 31, 2011 I don't know how true this is, but i have heard the the sliding x does not equalize well if it is already weighted (e.g. a leader falls, loads, then pulls a piece on the fall, so the direction changes).any thoughts on this? I personally use webbing with full strength lops on either end. It is easy to equalize, static and I am more comfortable building my anchors with webbing then rope. (mtntools.com/cat/mt/webolette/... kinda gimmicky but so easy...) wlashgrahamJoined Oct 24, 20100 points
 Mar 31, 2011 Evan Deis wrote:Larry your Finite Element Analysis is garbage. A cordolete cannot support a moment as your model can. This doesn't even make for a moderately good approximation. That's a really helpful comment Evan. @Larry: However, you should consider some elasticity in your rigging. If you use the traditional 7mm perlon cord which has significant elasticity, the load will be much more distributed. Pascal RipocheFrom Berkeley CAJoined Oct 14, 2010185 points
 Mar 31, 2011 wlashgraham wrote:I don't know how true this is, but i have heard the the sliding x does not equalize well if it is already weighted (e.g. a leader falls, loads, then pulls a piece on the fall, so the direction changes).any thoughts on this? I personally use webbing with full strength lops on either end. It is easy to equalize, static and I am more comfortable building my anchors with webbing then rope. (mtntools.com/cat/mt/webolette/... kinda gimmicky but so easy...) I actually read the same thing about the sliding X but cant remember where. However, about the webolette, I see one minor difference between webollet and cordalette : slings are (mostly) not elastic while a cordalette made of nylon cord is pretty elastic which can distribute the load over several protection. Pascal RipocheFrom Berkeley CAJoined Oct 14, 2010185 points
 Mar 31, 2011 wlashgraham wrote:I don't know how true this is, but i have heard the the sliding x does not equalize well if it is already weighted (e.g. a leader falls, loads, then pulls a piece on the fall, so the direction changes).any thoughts on this? I personally use webbing with full strength lops on either end. It is easy to equalize, static and I am more comfortable building my anchors with webbing then rope. (mtntools.com/cat/mt/webolette/... kinda gimmicky but so easy...) Which is why you should tie one strand a bit shorter than the other. Anyways, the worse a system equalizes, the better it resists unexpected extensions. Think of it like the differential on a car. You can have a regular differential which distributes half of the power (load) to each wheel all the time, but if one wheel slips (protection fails) so that it can't apply that power, then you get a spin out where neither wheel is applying power, or in the climbing analogy, a free fall where both pieces become unweighted until you hit the full extension of the system. By contrast, a limited slip differential would be like a load sharing system that binds up and if one piece fails, then the other pieces don't immediately lose all of their load. Also, a regular cordalette would be the equivalent of no differential, just driving both wheels at the same speed off of one axle. This means that the wheels can't spin out, but you might put all of the load on one side DannyUncannyFrom VancouverJoined Aug 27, 20105 points
 Mar 31, 2011 Has anyone here ever blown a piece from their anchor or had any problems with either anchor scenario failing in any way that wasn't due to their own mistake? Ben WalburnJoined Jul 13, 2007200 points
 Mar 31, 2011 Ben, Nope, but I have a survivors bias. There have been anchor failures over the years, though thankfully few. Given that the anchor is truly the last line of defense against death, it is worth putting a little too much thought into it. John Long's writeup of the Equalette is pretty humble about the fact that there really have been VERY few anchor failures, and to my knowledge none attributed to the poor equalization of the Cordalette. However most anchors are NEVER stressed beyond body weight. How many WOULD fail if they actually had to handle a factor 2 leader fall? I'm guessing the number is larger than we'd like to admit to ourselves. So the pursuit of ever better anchors is worth rehashing endlessly. Given some of the "anchors" I've seen other parties make, I'd argue this subject should not be downplayed. If you feel solid with your anchor skills, feel content to move on. Edit: These guys won't be posting up to answer your question: cascadeclimbers.com/forum/ubbt... MoofFrom Portland, ORJoined Dec 11, 20070 points
 Mar 31, 2011 Moof, The link to the actual accident report at the end of the thread you posted from CC is dead. The thread ended with speculation about whether or not it was actually anchor failure but someone was citing rock and ice as a source that it was anchor failure. The thread also mentioned the fact that this curious belay that failed was set behind a flake. Not sure what to make of the story but I will say that no intricate amount of anchor rigging can make a flake stick to the wall any better. If that was indeed the cause for anchor failure. Just curious if you know more details? YarpJoined Jan 16, 20110 points
 Apr 1, 2011 In the Gaines/Long book they tested equalization of a cordalette and found it did a very POOR job in vertically spaced anchors. It did a better job in horizontal anchors but not ideal by any means. Any off axis loading throws the whole thing out the door. Hence their equalette work. mattmFrom TXJoined Jun 2, 2006550 points
 Apr 1, 2011 Ya, I hear ya Moof. I'm not trying to be antagonistic here but rather simply posing a question that I'm curious about. I personally have never blown a piece in the 17 years I've been climbing and I am curious as to whether anyone else here has, how it happened and how it affected the anchor. Anyone?? Ben WalburnJoined Jul 13, 2007200 points
 Apr 1, 2011 Not a partial failure, but a 4 piece anchor that blew (all statically equalized using 4 clove hitches on a pair of double ropes). Only conjecture would answer whether the anchor would have held if it was better equalized: friendsofyosar.org/rescues/200... MoofFrom Portland, ORJoined Dec 11, 20070 points

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