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Degaine
climber
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Thanks for the sketches, goclimb.
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GOclimb
Trad climber
Boston, MA
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Here's the Gordolette. It's pretty cool, but a little too finicky for me. Still perhaps someone with some free time can refine the basic idea.
It's been a while since I've made one, and I drew this up from memory. If I have time this weekend I'll build the real thing and make sure it matches up with my sketch.
GO
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rgold
Trad climber
Poughkeepsie, NY
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Here is an anchoring solution I had sewn up for me recently. Sorry not to have pictures of it in use in the field (I've been out with it for several days of climbing, none with a camera in tow so far). All I have at the moment are the following indoor shots.
The idea is based on something I called the chopolette in the massive rc.com sliding X thread. It generated little interest there, in part because of a biner that had many sliding strands and the feeling that binding of strands would almost certainly destroy its effectiveness in equalizing.
In honor of its gimmicky nature (a source of embarrassment to me and a deal-breaker for Largo and others who believe in the primacy of simple tools) I've dubbed it the Geekqualizer, and admit, with regret, my passage to the Dark Side of gadget worship.
It consists of a commercialy available equalizing module with no crossing strands, and three arms that extend from the equalizing module and are clove-hitched to the protection. Here's what the whole unit looks like:
here's a closeup of the equalizing module and its connection to the arms:
and here is a view of a possible set-up for three pieces at different distances from the power point.
In the last picture, the left arm has been clipped to a far away piece with the loop sewn into its end, while the other two arms have been clove hitched to their biners, after which the end loop has been dropped into the biner as a backup to clove-hitch slippage.
Here is a closeup of the clove hitch and loop backup:
For those increasingly ubiquitous two-bolt anchors, the arms can be dropped and the equalizing module clipped directly to the anchors. The overhand knot at the right shortens the webbing and thereby decreases the extension if one of the bolts fails:
Four-piece anchors can be accomodated by adding a carabiner. The off-axis range is smaller for this set-up and of course there is more friction in the system.
The Geekqualizer wraps up into a small package somewhat smaller than a 7mm cordelette: Wrap-up is very simple and the time is about the same as for a cordelette. Installation time is the time it takes to make three clove hitches.
Advantages:
1. Adaptable to all anchor configurations with consistent installation. Regardless of the placement of the pieces, you rig it up the same way, with no choices or special adjustments. It is easily adapted to two- and four-piece riggings. (I think most of the other methods are tailored to a single fixed number of anchor points.)
2. Zero carabiner cost for two and three anchor points. Other than the always essential biners on the pieces and the power point biner, no other biners are required. Two Geekqualizer anchors consume the minimum of eight biners, whereas two equalette anchors (for three points) require ten biners and two mooselette anchors require twelve biners.
For the occasional four-point anchor, the Geekqualizer requires a total of seven biners, chained equalettes require ten biners, and the mooselette is, I think, out of the running.
3. A consequence of the zero carabiner cost is that there are no biners in the system that might be compromised by unanticipated cross-loading or gate opening. (The sliding X is especially susceptible to a very dangerous configuration if one of the pieces fails.)
4. Very fast installation for all configurations---no limiter knots to tie, adjust, and wrestle with when they become wet, tight, and cold, no potential need to readjust anything as there is with the cordelette, no special circumstances that the system doesn't work for. You clove (or clip) the arms, clip into the power point and you're on.
5. Equalization potential as good and perhaps better than other equalizing methods because of the lack of multiple crossing strands on a biner somewhere. Extension if one piece fails is about four inches.
6. Responds to off-axis loads and redistributes load if a piece fails (as do most equalizing systems).
Disadvantages:
1. Yet another special-purpose item. Although it can be used in other ways in an emergency, it isn't remotely as versatile as a cordelette.
2. Sewn webbing must be inspected and retired when appropriate.
3. Low-stretch material provides little energy-absorbing utility. Tying in to power point with rope is essential for the belayer. Followers who clip in, even temporarily, with a daisy should keep it tight and stay below the anchor. (On the other hand, low-stretch material might behave better when it comes to friction over the various pulley points.)
4. Potential for clove-hitch slippage may be a concern. There are some tests (private communication) that indicate this isn't a problem. Even so, one should be careful to tie the clove hitches without twists in the webbing and should make sure that the hitches are oriented so that the load-bearing part of the knot is close to the spine. (The clove hitch can often be backed up by half hitches around the arm before clipping the end loop to the biner.)
5. Friction. Friction is the reality death-knell of any equalizing system, and this is no exception. I think the elimination of crossing strands should prove to be an advantage (but know of no tests to address this question). There is still friction around all the rings. The worst case is when the strands all make full 180 turns around the rings---three pieces in a vertical crack. If systems such as this have a future, it lies in finding components that will reduce the friction. For example, it would be interesting to know how much difference roller biners on the protection points would make.
Remember, however, that the standards for acceptibility aren't very high, now that we are learning how bad the cordelette is, even with just two equal length arms. My guess is that even with their current levels of friction, the Geequalizer (and many of the other methods) provide equalization on average better than the cordelette provides, together with the advantages of off-axis load adaptibility and redistribution of the load to the remaining pieces if one piece fails.
6. No doubt perspicacious readers will come up with a slew more disadvantages in short order.
What I like about the Geekqualizer so far is that it is fast enough and simple enough for me to use automatically on every anchor. It costs me nothing in time, effort, and gear to use it rather than a more traditional method. The value in this corresponds to my feeling that something terrible is just as likely to happen in mundane casual circumstances as in the midst of some epic, and the instant you need the advantages of equalization, if such a time should come, may not be a moment that you can anticipate and so make special preparations for.
Test results post:
http://www.supertopo.com/climbing/thread.html?topic_id=307091&tn=308
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Ed Hartouni
Trad climber
Livermore, CA
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did you get Wootles to test it?
I'll think about friction later tonight...
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murcy
climber
San Fran Cisco
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nice, rgold!
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GOclimb
Trad climber
Boston, MA
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RG: A few thoughts off the top of my head. Can't replicate it, since I don't have the AE, but maybe I'll see if my buddy Jake who I see a few times a year will let me borrow his sometime.
1 - Looks nice!
2 - The issue of redundancy is a fairly serious one, and this doesn't get full marks. Let me define what I mean by the term redundancy:
A - If any one piece fails, the entire anchor will not fail.
B - If any one strand is cut, the entire anchor will not fail.
So the Geekqualizer passes part A, but gets an incomplete on part B. That is to say, if any of the strands radiating out from the AE are cut, you're fine, but if any of the strands within it are cut, everybody dies.
The CharlesJMM anchor and paired crossed slings do not have this particular failing.
3 - Once we allow ourselves to get geeky, steel rap rings could be substituted in for the biners to give other anchor types similar benefits. In other words, when you say Two Geekqualizer anchors consume the minimum of eight biners, whereas two equalette anchors (for three points) require ten biners and two mooselette anchors require twelve biners. this is comparing apples to oranges. The Mooselette could certainly be made with rings, and if so, would utilize the same number of biners as the Geekqualizer.
4 - As I think I mentioned before, to make a Mooselette on four pieces, all you need to do is pull down the four strands instead of three. It works for any number of placements. You'd simply need to add a biner for each additional strand.
5 - Friction. The Geekqualizer, as you said, has as many as 5 180 degree bends. That's an awful lot of friction. Compare that to: Pair of sliding-Xs - 5; Mooselette - 3 (only one of which typically moves much); CharlesJMM - 2 with a crossed strand, 3 without; equalette - 2. I imagine that this might give a fair approximation of how well each would equalize in the lab and the field.
6 - The fast/easy/idiotproof configuration seems like a huge plus!
Thanks for that!
GO
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johnboy
Trad climber
Can't get here from there
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While some of these other configuraions can't do cross platform (2 piece or 4 piece) anchors, your still left with a 20ft cord that can make up other types of anchors that do work on 2 or 4 piece anchors. I guess what I'm saying is, different situations call for different anchors and a 20 ft cord can do many different things.
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wootles
climber
Gamma Quadrant
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did you get Wootles to test it?
Wootles walks by, hands in pockets, whistling, and avoiding eye contact.
I can see I'm going to have to step up the efforts to get new load cells.
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Ed Hartouni
Trad climber
Livermore, CA
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Feb 10, 2007 - 12:14am PT
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The way that Richard's Geekqualizer works is that the red sling is free to slip and extend under the force of the fall. The slipping is necessary to equalize the forces on the blue slings.
If the red sling is not free to slip then it does not equalize.
The friction can be a large issue. For a sling looped around a ring, the forces can be unbalanced because of the friction. If F0 is the larger force, and F1 the smaller, on each strand of the sling, then the sling will not slip when:
F1 = F0/exp(2*mu*pi)
where mu is the coefficient of static friction and pi = 3.1415...
If mu = 0.4 then F1 = 0.08*F0 or roughly 1/10th the force... put an other way, a 1 lb weight on one side can hold a 10 lb weight on the other.
This is not at all surprising, since that is the way a belay device works.
For multiple bends, these forces multiply, which is GOclimb's point. For a sliding-x there are actually 4 bends, one at each anchor and two at the clip-in 'biner, since the webbing is doubled there. In this case it is a bit more complicated since the normal forces on the inner webbing is increased by the outer webbing. It is possible that this large friction is the reason why the sliding-x did poorly in the Largo/wootles test.
I'll try to measure the static coefficience tomorrow (it's raining in California) to get an idea of how big the problem is...
...my intuition is that the friction is the big problem here.
Of course, one could coat the rings in teflon (or use teflon tape) which would considerably reduce the coefficient. Since this is exponential, it should make a big difference.
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Paul Raphaelson
Ice climber
Brooklyn, NY
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Feb 10, 2007 - 12:15am PT
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I'm looking at variations on the Sliding W.
Besides extension, and lack of redundancy, are there problems with the strands binding? If so, are they catastrophic (rope burning itself) or minor (imperfect equalization due to friction)? If the binding isn't a serious issue, consider this ...
I just did a couple of experiments at home and found that the amount of extension from a typical sliding W setup is actually pretty minor. And it can be greatly reduced by tying one of the strands short (with an overhand or an 8) in order minimize the length of the rigging. You can get some (imperfect) redundancy by tying the rope into the power point biner with a clove hitch, and then backing it up with a figure 8 onto the strongest piece of pro.
Not a perfect setup, but it has some things going for it:
-simple. uses no extra gear, easy to evaluate, faster even than a cordelette.
-excellent equalization, assuming binding of the strands isn't an issue
-extension can be limited to 1 or 2 feet in most cases
-some redundancy is available with minimum effort by using the climbing rope.
On another note, I tried the variation on the sliding W that has overhand knots tied in the outside strands. It didn't work properly. It looked as if it would, but it did not equalize. All the load went onto the outside pieces, and was born by single strands on each side. This is difficult to explain ... I suggest trying it to see what the issue is.
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rgold
Trad climber
Poughkeepsie, NY
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Feb 10, 2007 - 02:14am PT
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"Question: Are you going to use this yourself as a default anchoring tool?"
Yes, for a while anyway. I want to see how much trouble it is in real life.
I don't see myself using the other three-placement anchor systems; they seem tricky to set up, they consume too many biners, I don't understand how they'll perform in all circumstances (there seems to me to be a wrong way to clip the bottom loops of the Mooselette, for example), I'm not sure I can reliably tell from visual inspection when everything is ok, and I don't trust myself to think about any of these things clearly when I'm tired, cold, and in a rush to get down before dark. I don't think any of the ones that purport to equalize three anchor points have fewer friction problems than the Geekqualizer. They may be fine for other people, but I'm a very slow thinker and I make a lot of mistakes on my way to understanding things.
I have very rarely carried a cordelette---mostly I tie in with the rope, so using a special-purpose anchoring gadget is two giant steps in a different direction. But I'll try it out for a season anyway and see what I think after that.
"did you get Wootles to test it?"
There's a chance that Wootles might have a job and a life, and this makes me just a wee bit reticent to ask him to test stuff, especially when he'd need three load cells to see the effect of friction. First I'm going to see if I can stand using the Geekqualizer, 'cause if I can't, why test it? (I'm not concerned about it being worse than the methods I typically use.) In any case, at present I only have two Geekqualizers (under the extremely optimistic assumption that I can convince a partner to carry and use one).
Friction:
I've already said that friction could kill the whole show, and that finding ways to reduce it like Ed's teflon coated rings could be the key to any reasonable success. I'm gonna look into his teflon tape idea....
As for comparisons, I don't think that, for example, the Mooselette fairs any better than the Geekqualizer. In my possibly mistaken reading of Gabe's diagram, the Mooselette appears to have seven bends around biners compared to the five bends around rings in the Geekqualizer. Two of the Mooselette bends are at relatively large angles, in some cases (e.g. the indoor picture posted earlier as opposed to the sketch) so large as to be insignificant, in which case the number of bends could in some cases be effectively as low as 5, the same as the Geekqualizer. However, the Mooselette has three strands interacting and possibly binding at the power point biner, whereas the Geekqualizer has no such interactions. I don't see any a priori way of predicting which might be better, and even if they had the same average performance, the binding potential in the Mooselette and other designs raises the possibilty of bad worst-case performances.
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Ed Hartouni
Trad climber
Livermore, CA
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Feb 10, 2007 - 02:26am PT
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nylon-nylon coefficient is reported to be 0.15 to 0.25, which reduces some of the webbing on webbing binding, but the real problem I think is the increased normal force caused by one strand of the webbing being on top of another over a 'biner or ring.
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Ed Hartouni
Trad climber
Livermore, CA
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Feb 10, 2007 - 02:14pm PT
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The tests for measuring the friction of slingage on 'biners is complete and the conclusions are rather interesting. I believe that they may even be informative.
"Executive Summary"
I'll tell the story here with the technical details below for the geeks out there.
There wasn't much difference in using a big pear 'biner or a regular D... hanging a weight on one side and counter balancing it with a weight on the other you find that a 10lb weight can support a 22lb weight because of the friction. This can complicate a system which depends on the sling to slip around to equalize because 2-to-1 forces have to develop to do it... add more 'biners and you add more imbalance.
The sliding-X was really interesting. Using 9/16" webbing you find one strand sitting on the other. A 10 lb weight held a 65 lb weight statically in this configuration. The perlon sliding-X had the strands sitting next to each other, and the frictional forces were greatly reduced, 10 lbs held 25 lbs, slightly higher than just looping the strands.
If you are going to use the sliding-X, use materials that sit next to each other, not on top of each other! I think the common usage of slings to build a sliding-X should probably NOT be recommended as the equalization properties are defeated.
The tests
The test was conducted by hanging the sling over a 'biner so that the loop made 180º contact with the 'biner. Two weights were hung on either side of the sling. One of the weights was increased until the sling moved. The coefficient of static friction can be calculated by using the formula:
mu = ln(F2/F1)/pi
where ln(F2/F1) is the natural logarithm of the ratio of the greater weight to the lesser weight and pi = 3.1415...
The slings used were a 9/16" wide tubular nylon web, and a 7mm perlon cord.
They were looped both in just a single strand, and in the "sliding-X" configuration.
Two 'biners were used, a large pear 'biner that I use for belaying, rappeling, etc, and a "D" 'biner that I use for "normally" for climbing ropes to anchors, etc. I wrapped Teflon tape on the large pear 'biner to see if it had any effect, it did not.
What I find is that the coefficient of friction is in the range of 0.22 to 0.31 for all slings and 'biner configurations. This gives a force ratio of anywhere from 2 to 2.7 on the 'biner, that is, one strand can have as much as 2 to 3 times the force on it than the other. This would be an issue in a belay rig that is stressed close to the breaking strength of the sling, one side might blow first because the sling isn't able to equalize the force by sliding around the 'biner.
The sliding-X configuration was very interesting. The coefficients were much higher in this case, with the 9/16" sling being in the range from 0.5 to 0.6, able to maintain a force ratio in the range of 5 to 7. This is primarily caused by the fact that one strand of the webbing sits on the other.
The 7mm perlon sliding-X did a better job, the strands sit next to each other. Here the coefficients ranged from 0.29 to 0.4 with force ratios from 2.5 to 3.5.
The data
sling,carabiner,configuration,static,F1 (lbs),F2 (lbs),F2/F1,mu
9/16,large pear,looped,yes,3,8,2.67,0.31
9/16,large pear,looped,no,10,25,2.50,0.29
9/16,D,looped,yes,10,22,2.20,0.25
9/16,D,looped,no,10,25,2.50,0.29
9/17,large pear-Teflon,looped,yes,10,22,2.20,0.25
9/18,large pear-Teflon,looped,no,10,25,2.50,0.29
7 mm,large pear,looped,yes,10,20,2.00,0.22
7 mm,large pear,looped,no,10,22,2.20,0.25
7 mm,D,looped,yes,10,22,2.20,0.25
7 mm,D,looped,no,10,25,2.50,0.29
9/16,large pear,sliding X,yes,10,47,4.70,0.49
9/17,large pear,sliding X,no,10,50,5.00,0.51
9/18,D,sliding X,yes,10,65,6.50,0.60
9/19,D,sliding X,no,10,70,7.00,0.62
7mm,large pear,sliding X,yes,10,25,2.50,0.29
7mm,large pear,sliding X,no,10,30,3.00,0.35
7mm,D,sliding X,yes,10,30,3.00,0.35
7mm,D,sliding X,no,10,35,3.50,0.40
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Paul Raphaelson
Ice climber
Brooklyn, NY
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Feb 10, 2007 - 03:02pm PT
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Has anyone looked at the friction properties of the sliding W?
There's definitely a lot of friction going on. I'm actually less concerned about perfect equalization than I am about what happens if a piece blows and there's extension. I worry that that much cord sliding over itself could cause some burning/shredding ... especially troublesome since the configuration doesn't have built-in redundancy.
If this isn't likely to be an issue, then I'm going to pursue variations on it as a solution.
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Ain't no flatlander
climber
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Feb 10, 2007 - 03:31pm PT
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First, it's "pear" not "pair" though it would be interesting to see how a pair of pears performs. Largo suggests that anodized biners slide better too. Please try your tests with the new generations of 8mm Spectra webbing, which is becoming much more common on many climber's racks.
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Ed Hartouni
Trad climber
Livermore, CA
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Feb 10, 2007 - 04:43pm PT
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my guess is that you can't tell the difference between the spectra and the nylon tube...
I did change the spelling....somedays are just like that though...
the friction is dominated by the schmutz on the surfaces... we all know that a dirty rope has more friction moving in a belay device.
and the 'biner used to be anodized, but if you use them a reasonable amount they aren't pretty quickly.
multiple 'biners also shouldn't change things, the way they work with a belay or a rap is to increase the contact angle, in this set up it probably wouldn't do that (angle would still be pi).
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jstan
climber
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Feb 10, 2007 - 05:23pm PT
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Sloppy, but hey. Good enough for Topo work.
sling---carabiner--------config.----static---F1(#)---F2(#)---F2/F1--mu
9/16-----lg pear--------------looped-----yes-----3----------8-----=2.67-----0.31
9/16-----lg pear------------- looped-----no------10--------25-----2.50-----0.29
9/16-----D---------------------looped-----yes-----10-------22-----2.20-----0.25
9/16-----D---------------------looped-----no------10--------25-----2.50-----0.29
9/17----- lg pear,Teflon---looped-----yes----10--------22-----2.20-----0.25
9/18----- lg pear -Teflon--looped-----no-----10---------25-----2.50-----0.29
7 mm----- lg pear --------- looped-----yes---10--------20-----2.00-----0.22
7 mm----- lg pear ----------looped-----no-----10--------22-----2.20-----0.25
7 mm-----D-------------------looped-----yes----10-------22-----2.20-----0.25
7 mm-----D-------------------looped-----no-----10--------25-----2.50-----0.29
9/16----- lg pear -----------sliding X-----yes--10-------47-----4.70-----0.49
9/17----- lg pear -----------sliding X-----no----10------50-----5.00-----0.51
9/18-----D-------------------- sliding X-----yes--10------65-----6.50-----0.60
9/19-----D---------------------sliding X-----no----10------70-----7.00-----0.62
7mm----- lg pear ---------- sliding X-----yes--10------25-----2.50-----0.29
7mm----- lg pear -----------sliding X-----no----10-----30-----3.00-----0.35
7mm-----D---------------------sliding X-----yes---10----30-----3.00-----0.35
7mm-----D-------------------- sliding X-----no-----10----35-----3.50-----0.40
Does "No" in the static column mean it is a test of sliding friction? If so, I remember coef. static friction as generally being larger than sliding friction. ?
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Jingy
Social climber
Flatland, Ca
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Feb 10, 2007 - 05:31pm PT
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I never do it. I boulder. No fuss no muss.
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Ain't no flatlander
climber
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Feb 10, 2007 - 05:33pm PT
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I suspect the 8mm spectra will test closer to your 7mm cord due to slipperiness and a shape that is nearer to round.
As for anodizing, if it's shown to make a significant difference then that may be an argument for using hard anodizing on locking biners instead of the soft sulfuric anodizing that is currently used. Nobody makes a hard anodized biner...yet.
c'mon AAC, get your feces cohesive and do something useful for a change.
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Ed Hartouni
Trad climber
Livermore, CA
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Feb 10, 2007 - 07:10pm PT
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"No" means it did not hold statically, so the actual value of sliding is somewhere in between those two. Since the range is small, probably smaller than the variations in the coeff. I just bracket the values (usually within about 10% of the total weight)...
I also got a BD dynema sling to see what that's all about, but now I'll have to go back and get a new pear 'biner with anodization... which I don't think is work while. The schmutz factor will dominate any surface preparation.
You used to be able to get a nice nylon pully that fit in the 'biner. Something like that could be made out of teflon (or some other slippery material) and used in this "special" case...
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