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tradklime
Mar 23, 2006, 3:23 PM
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In reply to: Sorry guys- (Just my personal opinion but...) The astroglide is a creative solution, but it simply fails when I put it through my own personal KISS test.
The 5:1 stuff perhaps, but the standard version is just marginally more complicated than an equalette, and quite possibly as easy/ quick to set-up.
The pictures are somewhate hard to follow, but I think once you figure it out you'll see how straight forward it is.
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glowering
Mar 23, 2006, 3:27 PM
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justhemaid,
Have you tried it a couple times?
I think visual inspection is a good first step. But like Craig dissing the Sloppy :lol: - slidingX without having tried it (he would have discovered the danger he describes is actually more of an issue in the troublette), you've got to try these things a few times before you pass judgement.
I think Dingus' astronaut anology is a good one. There's a lot of complex stuff going on behind the scenes for a space walk, but the engineers make actually doing it as simple as possible.
If you have the AstroGlide partially pre-rigged, all it requires is to clip your four loops in to the pro and tie two overhand knots. Even if you screwed it up, or one of the biners in the middle failed there just isn't much more cord available to allow for extension.
After having tried it a few times, I am thinking it will probably end up being my anchor 90% of the time for 3 piece anchors.
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shorty
Mar 23, 2006, 3:29 PM
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In reply to: The astroglide is a creative solution, but it simply fails when I put it through my own personal KISS test.
In reply to: I wouldn't use it in real life, but it is interesting. |
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justthemaid
Mar 23, 2006, 4:46 PM
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[quote="glowering"]justhemaid,
In reply to: Have you tried it a couple times?
Yes, more than a couple of times. It's simple for those of us who have been following all this stuff, but if I can't teach it to someone unfamiliar with this thread in under 5 minutes- it fails my KISS test.
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papounet
Mar 23, 2006, 5:19 PM
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In reply to: In reply to: very intersting setup process: extremely straightforward. But it ends up doubling the connecting cord going to each pro and using single strand to provide the sliding x balancing function in the upper parts. the end results looks very much like two small equalette for the 2 sets of 2 anchor but you clip only one center strand to be used by the lower sliding X. Papounet, “…..But it ends up doubling the connecting cord going to each pro…..”. The connecting end going back to the middle anchors will only endure load when failure of it’s pair anchor occurs, otherwise it remains unloaded.
I am not disputing that one strand is only going to support the load if failure. I am just remarking that in term of usage of cordage, your design eats up as much as the mhabitch design or my equalizer:
the cord goes single from shelf limiter knot to pro1 back through biner connected to shelf limiter knot to your overhand arm limiter knot to the pro2, in a loop to pro2 and back to the arm limiter knot and then to the shelf limiter knot: you have one strand going up and one strand going down from each pro from and back to the "shelf" eventhough the overhand you ahve introduced in the full equalizing setup "isolates one part of a strand unless failure
In reply to: “……and using single strand to provide the sliding x balancing function in the upper parts……” Using single strand reduces friction thus improving equalization; in case of cord rupture at that precise point, the other pair of anchors will take over. “…..the end results looks very much like two small equalette for the 2 sets of 2 anchor but you clip only one center strand to be used by the lower sliding X…..” I´m trying to visualize the 2 equalettes you perceive, but I only see 2 Vs on top supporting another V at the bottom. Besides, 1 pair of anchors of an equalette will not equalize on their own, they need to be connected to another arm (1 or 2 anchors) to achieve equalization; in contrast, one pair of anchors of TIA will in fact equalize on their own. Also, the strand going from the middle anchor to build the master point has enough slack so that no additional load is inflicted to that anchor.
I called them equalette because an equalette used with 2 points is a pre-rigged V where two biners sliding over 2 strands replaced the single biner sliding over the crossed strands. If you are using a biner to balance the load between the two: no limiter knot => an full equalizer, one limiter knot => a astro-glide (asymetric loading, the leg with the knot get 50% of what the other arm gets), 2 adjustements knots => mhabitch mode
In reply to: Edited to add : I have just realized that in a three points Equalette, the collapse of the unpaired anchor will result in a 2 point fixed knot anchor which provides no equalization; therefore, the Equalette would in fact turn into a non equalizing Cordelette; will this resulting configuration handle the load that induced the collapse of the individual anchor?. In the case of TIA, b----, Astroglide and maybe other designs I forget, the collapse of the unpaired leg will result in an equalizing subsystem, a very important trait to possess.
The equalette is a better setup thant the "classical cordelette".
It works wonder for 2 points setup as it is a pre-rigged better-sliding V.
It works rather well for 4 points as it distributes at least on one pro of each pair, but is quality depends on how well it has been pre-tensionned by the clovehitch and on the not-so -negligable adjusteemnt of the clovehitch underload.
For 3 points, it would be better to connect 2 arms of each pair to the center piece as it will avoid the problkme you just highlighted
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glowering
Mar 23, 2006, 6:18 PM
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justhemaid,
Fair enough. That's a good test. I'll have to see if I can teach it to my partners in under 5 minutes. And if/how they screw it up trying it after brief instruction.
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charlesjmm
Mar 23, 2006, 6:33 PM
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In reply to: In reply to: Charles, So could you talk a bit more on why the four overhands? I guess if I were going the clipped overhand route I'd just go with a single pair of overhands and maybe even just clip through them versus around. I agree the inline-8 is bulky, though I need to try it on 5.5mm., but it probably it the "proper" knot for the job. As for equalization and extension we've already discussed our differing predilictions there and that I just think mhabicht's top-cloving / bottom equalizing is way superior for the extension control on each individual point it provides. It's also just as fast and the biners don't really need to be lockers. Healyje, the main intention of that post was to suggest the simplest rigging procedure I could think of to help the novel Equalette based designs gain broader acceptance. During this search, I found the additional overhands made calibrating the whole structure significantly easier (at least for me); but you are right, they are indeed superfluous.
Let me retract the highlighted comment and replace it with this :
The two additional overhand knots do indeed provide a useful feature at a minimum cost : they incorporate the all forgotten and many times handy Shelf, specially during self-rescue maneuvers ; I recall a post commenting the lack of it in the novel designs.
Here is the AstroGlide 3:1 featuring the resurrected Shelf :
http://i49.photobucket.com/.../Astro4overhands.jpg426x568 - 70 K
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charlesjmm
Mar 23, 2006, 6:57 PM
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In reply to: justhemaid, Fair enough. That's a good test. I'll have to see if I can teach it to my partners in under 5 minutes. And if/how they screw it up trying it after brief instruction.
Justhemaid, Steve,
I think you are putting the Astroglide in unfair terrain. The guinea pigs should comprise climbers often needing 3 - 4 point equalization. In your test, the AstroGlide is batting hands tied against the local team……
.
Edited to add :
I´ve risked making this comment not knowing your climbing partners, though; did not mean to imply anything about them…..
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knudenoggin
Mar 23, 2006, 9:41 PM
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In reply to: I use 5.5mm spectra cord for my cordelettes. It is stronger than 7mm perlon (but I guess weakens over time with flexing, so should probably be replaced more often) (it is more than strong enough for one strand going to each piece). It is very slippery (must use triple fisherman's), so it would be interesting to see the difference in friction between spectra and dyneema slings
Please read Tom Moyer's paper "Comparative Testing of High-Strength Cord",
in which he found just the opposite to be true, in some cases (and dramatically
so, in some cases!
E.g., in a single strand tied with Fig.8 loopknots, the Sterling 7mm nylon cord
was stronger than the Vectran-/Spectra-/Technora-cored cords.
Tied in a sling (Dbl. or Trpl. Fish.knots), 7mm nylon was stronger...!
And, more relevantly, in the drop tests on a cordelette single leg, only one of
the hi-mod cords (Spectra+Kevlar Maxim) survived 5 drops, as did the 7mm nylon
(and the then Sterling Vectran cord didn't survive EVEN one!).
This hype of presenting a somewhat fictitious, high tensile strength is a serious failing
of vendors to advertise the products helpfully. --just get a great-looking number out
for the consumers to swallow. But unless you want to strip the polyester sheath and
splice the hi-mod core, you won't realize that tensile figure. Knotted, that stuff
is suffering a reduction in strength unseen in older cordage materials.
(Yes, improvements are being made, it seems. But let's see the test data.)
*knudeNoggin*
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knudenoggin
Mar 23, 2006, 10:23 PM
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In reply to: These anchors are getting beyond ridiculous. Dingus is right. It's not that they are too complex for me to rig, it's that they are unnecessarily complex for the job. There is simply no reason introduce all this clusterf-ckedness.
situation of climbing fatigue put forward by DMT!
In reply to: In reply to: As far as your anchor proposal goes, there are several objections; here are a few: 1) In the 3-placement version, it's Yet Another Anchor Design That Doesn't Equalize (TM); it's a 25%-50%-25% design if I understand your photo Yes, and I say, so what? This worry over 25-50-25 is silly.
and if any one leg fails (anchor pulls), they're all 50-50. So one might as well
equip to set up for 4-points & 25-25-25-25 and just adapt to 3-points by accepting
50% on whichever leg. KISS.
In reply to: In reply to: 2) It's limited to certail placement locations because of the way it uses runners. No it isn't. Certainly no more so than any of the other rigs in this thread. The difference with mine is there is no tying/retying of knots necessary. Add a sling or draw here or there if it won't rig your placements as is.
need much re-tying, either; maybe pre-tied knots get adjusted in one or the other
anchoring pairs, but that's simple.
In reply to: 3) It uses knots in Spectra/Dyneema webbing--that's a no-no.
masterpoint structure (what I call "ELET") would be a risk in HMPE dental floss?
--an OOBend in tape taking half the impact force?
Where's some published data on this? (Vendors like selling sewn slings.)
We're not bound to a particular material, though. Your friction testing showe this to be
pretty ideal, and I'd like to see testing on the knotting of such tape.
In reply to: In reply to: 4) Your master point structure amounts to a cumbersome equalette and suffers the same central problem as a knot-limited equalette (or sliding-X): unequal loading unless the supporting strands are exactly equal. My master point is 2 "troublettes".
use Troublette/ELETs in each anchor pair vice Sliding-Xs? --you really think
rigging needs would make sizing the former so hard?).
*kN*
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glowering
Mar 23, 2006, 10:52 PM
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In reply to: In reply to: I use 5.5mm spectra cord for my cordelettes. It is stronger than 7mm perlon (but I guess weakens over time with flexing, so should probably be replaced more often) (it is more than strong enough for one strand going to each piece). It is very slippery (must use triple fisherman's), so it would be interesting to see the difference in friction between spectra and dyneema slings Please read Tom Moyer's paper "Comparative Testing of High-Strength Cord", in which he found just the opposite to be true, in some cases (and dramatically so, in some cases! E.g., in a single strand tied with Fig.8 loopknots, the Sterling 7mm nylon cord was stronger than the Vectran-/Spectra-/Technora-cored cords. Tied in a sling (Dbl. or Trpl. Fish.knots), 7mm nylon was stronger...! And, more relevantly, in the drop tests on a cordelette single leg, only one of the hi-mod cords (Spectra+Kevlar Maxim) survived 5 drops, as did the 7mm nylon (and the then Sterling Vectran cord didn't survive EVEN one!).
I looked into cord when I bought some, but hadn't see that article (url below) as far as I remember. I'd hate go to 7mm due to the added bulk, but that may be better. Someone earlier mentioned the dynamic 8mm cord, that may be the best, but even bulkier, sigh. If I remember right, does the spectra/kevlar have a core that is brownish and very thin strands, while the regular Spectra looks more like regular nylon?
http://www.xmission.com/...gh_Strength_Cord.pdf
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vivalargo
Mar 24, 2006, 5:54 AM
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I can't claim to have studied this entire thread but I suspect our original intentions, after the testing, have perhaps been slightly taken off course.
The tests shows conclusively that the unequal armed cordelette does not work as advertised. Not even close, and for all the reasons stated by Richard G. and others. Our concern was that the unequal arm cord. equalized so poorly that it provided an anchor that was probably not even redundant. Remember that "redundant" in this context means that you never let the loading fall on one piece of gear. With the unequal cord., the load basically slams onto one primary anchor placement--the one clipped to the shortest arm. This makes the cord. unequal length a merely backed-up anchor, not a redundant one.
The birth of the equalete was to provide a redundant anchor strategy, meaning that at least two arms were bearing pretty equal force during a fall, and if used to connect one or two additional anchors (making 3 or 4 total), some loading would go to those anchors as well. The idea was never to try and concoct a perfectly equalized anchor, which is only called for a few times in any climber's life. When you combine this with the fact that it is very rare to not be able to arrange pro right off the belay, which would preclude a leader falling onto the belay anchor, the chances of ever finding a belay with all mank placements and a lead above with no pro--well, the odds are very remote.
So while I applaud folks and their efforts to cook up a perfectly equalized anchor strategy, I feel it would be called for in only the most exceptional circumstances. This gives the nod to a simplier system sans doo dads and complications. So far the equalette (now field tested on walls, ice climbs, adventure routes and sport) has worked well, and with about three anchors worth of practice is just as fast to rig as the cordelette.
It has to be a simple rig to catch on, lest people just stick with the old cordelette, which is neither equalized or redundant in the strict sense.
JL
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healyje
Mar 24, 2006, 6:18 AM
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John,
I think, or at least hope, we all understood you were never looking for an anchor that was "perfect" in any respect. But I have encountered enough ghastly anchoring problems that did require significant equalization that I am interested in exploring these equalization designs. So far only mhabicht's equalette variation and now Charles' astroglide have really caught my eye in a "whole rig" way; the rest I find interesting from a component/concept perspective. So while I basically agree with you - I definitely like having some equalization options up my sleeve for the next time I'm dealt a less than happy set of options for an anchor. There has been some interesting discussion since you "signed off" back on 40, but I have no doubt you got what you needed even before then. Thanks again for the challenge, the testing, and posts - good luck on your new anchor volume - I'll keep my eye out for it...
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papounet
Mar 24, 2006, 9:12 AM
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Dear John,
ALthough one would hope that climbers don't get in situations where the NEED for absolutely equalized anchors arises, I am of the opinion that at least one fatal acident (Tahquiz) could clearly have been avoided by the usage of another anchor system than the one used.
I also believe that dubious terrain is encountered more often than not by some climbers. (I am leaving for 2 weeks desert climbing in algeria saturday).
The discussion so far has made clear that:
classical cordelette < equalette < mhabicht
1. other variants such as astroglide or my own spider or equalizer balance of pros and cons have not convinced so far
2. for 2 pieces anchor, the equalette is "an improved sliding X" and works wonders. the mhabichtvariant is neither necessary nor applicable
2. for 3 pieces, even if you accept the 25%,50%,25% distribution, you have to setup the equalette as if it was a 4 anchors (having 1 strands of each side going to the middle placement).
I would like to congratulate you on your willingness to adress the weaknesses of your earlier cordelette. I hope that the same honesty will move you to continue to challenge your new concept.
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papounet
Mar 24, 2006, 9:29 AM
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Should I confess that it was not until page 54 that I truly understood the astroglide concept ??? :oops: :oops:
The good point: it is easy to build in a sort of process
Start with equalette
2 placements, no more work required
4 placements, install 2 more biners, set up a mhabitch variant
3 placement, begin to setup the mhabitch variant using the center pro for both sides, don't tie the clovehitch, add the two overhand knots
The not-so-good point:
The atroglide manages 33%,33%,33% distribution over 3 pro at the "cost" of having 66%,33% in case of failure.
For 3 placements
the astroglide has to be evaluated against
- the 3 way sliding X (with one or 2 biners)
- the gordolette
- the alpine equalizer (either commercial or handmade with your knot of choice)
- the pulley system
- the spider system (ELET triangle concept is totaly similar)
- the mhabitch variant with the center pro used twice
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charlesjmm
Mar 24, 2006, 4:24 PM
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The litmus test I would propose for anchor analysis is :
1) Applicability to 2, 3 and 4 placements - horizontal & vertical
2) Attainable load distribution (equalization or unbalanced)
3) Load management behavior under failure scenarios
4) Applicability to random sets of anchor arrangements
5) Convenience : ease of use, rigging time and removal
6) Gear requirements
7) Shelf?
An anchor design scoring high in all criteria would certainly be a nominee for the “90% of cases” award.
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glowering
Mar 24, 2006, 7:42 PM
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8) Simplicity (i.e. KISS)
I think everyone has their own idea about what the priority of those 8 criteria should be.
Personally I am willing to give up a little simplicity (e.g. the AstroGlide being a little more complicated than the Equalette) for better load distribution (AstroGlide vs. Equalette), and rigging time (two overhands AstroGlide vs. 4 clove hitches Equalette).
I would hate to see the mhabicht and the AstroGlide not presented to people because they aren't simple enough to catch on with the general population for most anchors. Some people would be willing to forgo simplicity for the other benefits. Maybe throw them in the appendix for paranoid tech geeks :lol: . I can look at the look at the mhabicht (DuoGlide) or AstroGlide and immediately tell if it's tied right, and then I worry less about that sketchy fixed pin, and dimpled Alien :shock: .
Also Largo, if you do check this thread again, I'd appreciate it if I could get your take on the slidingX powerpoint variant I proposed on pg. 50 as an alternative to 2 lockers on the two strands on the bottom of the equalette. Craig C mentioned the danger of having one strand too long (the limiter knot could pull through), but it would have to be very long for that to be an issue.
http://www.rockclimbing.com/...hp?p=1335828#1335828
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papounet
Mar 25, 2006, 2:28 AM
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In reply to: 8) Simplicity (i.e. KISS) Personally I am willing to give up a little simplicity (e.g. the AstroGlide being a little more complicated than the Equalette) for better load distribution (AstroGlide vs. Equalette), and rigging time (two overhands AstroGlide vs. 4 clove hitches Equalette).
why would you prefer the astroglide over Mhabicht variant ?
AStroglide with 4 points 33%,17%,17%,33% load distibution; if faliure , 50%,17%,33%
AstroGlide with 3 points 33%n33%,33%, if failure, 66%, 33%
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charlesjmm
Mar 25, 2006, 6:18 AM
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The choice of the most advantageous anchor solution would depend on the initial load distribution satisfying your requirements. Do you want to rely on uniform load distribution from the start or want to postpone uniform load distribution to attend failure scenarios? Since you really don’t know which placement will fail, wouldn’t it be better to delegate duties equally amongst anchors from the beginning?
Could it be argued that an initial unbalanced load distribution could contribute to failure? Controversial terrain indeed …..
For 3 placements and 33/33/33 -> AstroGlide. Failure : 33/66
For 3 placements and 25/50/25 -> Equalette variant. Failure: 50/50
For 4 placements and 25/25/25/25 -> Equalette variant. Failure: 25/25/50
For 4 placements and 33/17/17/33 -> AstroGlide. Failure : 33/17/50
I would choose uniform load distribution from the start, i.e., I will setup AstroGlide for 3 placements and Equalette variant for 4 placements.
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glowering
Mar 25, 2006, 12:01 PM
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In reply to: I would choose uniform load distribution from the start, i.e., I will setup AstroGlide for 3 placements and Equalette variant for 4 placements.
Me too.
And also for speed/ease of setup. 3 pieces = AstroGlide because it only needs two overhands (vs. 4 cloves for Mhabicht). 4 pieces = Mhabicht because although you could tie overhand limiter knots in all 4 arms of the AstroGlide for 25/25/25/25, the 4 cloves will be easier to adjust in the Mhabicht.
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justthemaid
Mar 25, 2006, 5:56 PM
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In reply to: And also for speed/ease of setup. 3 pieces = AstroGlide because it only needs two overhands
Does it really need two?
I just tied it with ONE overhand in the center lines. Seems to work. It's even easier.
What do you guys think?
I can't post a picture- maybe Glowering or Charles could try it and give an opinion/picture for us.
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charlesjmm
Mar 25, 2006, 11:15 PM
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In reply to: In reply to: And also for speed/ease of setup. 3 pieces = AstroGlide because it only needs two overhands Does it really need two? I just tied it with ONE overhand in the center lines. Seems to work. It's even easier. What do you guys think? I can't post a picture- maybe Glowering or Charles could try it and give an opinion/picture for us.
That would be a neat trick to use when you set up a symmetric and compact arrangement (picture 1); however, take a look at picture 2; this arrangement forces you to place 2 overhand knots.
The distance between the biner and the overhand knot should be at most 2-3 inches.
http://i49.photobucket.com/...verhandExplained.jpg720x540 - 46 K
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justthemaid
Mar 25, 2006, 11:51 PM
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Thanks Charles- Should have tried uneven placements before posting.
Two knots is better, although the one could work sometimes.
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domx
Mar 26, 2006, 11:16 PM
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I have read through pages 7 and i am questionning the efficiency of the sliding X with limiter knots anchor in the situation of a traversing route where the a leader fall could bring the master point all the way to the limiter knot loading only one arm of the anchor ?
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domx
Mar 26, 2006, 11:18 PM
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I have read through pages 7 and i am questionning the efficiency of the sliding X with limiter knots anchor in the situation of a traversing route where the a leader fall could bring the master point all the way to the limiter knot loading only one arm of the anchor ?
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