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j_ung
Mar 17, 2006, 6:01 PM
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In reply to: BTW, in light of the recent findings I hope that Long changes SRENE to SRELE (or something with the same intent). SOLID--REDUNDANT--EQUALIZED--LIMITED EXTENSION.
The "S" in SRENE actually stands for Simple. :)
Aaaaand... that's a nice segue into what I wanna say. The old pre-equalized tie-off (called a "cordalette" in this thread) is so damn simple. And while I'm absolutely floored by the creativity and imagination of this entire thread, I think the vast majority of anchor systems being bandied about are anything but simple. If they don't require additional biners, they require additional knots or complex rigging that is difficult to learn and more difficult to teach to someone else. Furthermore, most of these anchors don't have a key feature of the "cordalette," namely a shelf, which helps to organize a belay, especially in abnormal situations, such as self rescue. Some of them even sacrifice redundancy for equalization. While I can accept limited extension, I can't accept a lack of redundancy!
Here's what I like the best so far:
http://img506.imageshack.us/...sc0097changed0un.jpghttp://img506.imageshack.us/...sc0098changed4qq.jpghttp://img353.imageshack.us/...sc0099changed0lr.jpg
From left to right: a redundant sliding X (note the additional clip-in point made from the back strand of the clove hitch); a redundant sliding X with one limiter knot to shorten any potential extension even further; a spread version, with the far piece extended via runner.
Tradklime, you'll notice that this is similar to what you just posted. Your rig is sweet, but I think it's still too complex. First off, you don't need that special knot -- a single overhand in the middle of a pre-looped cordalette will work just as well. Second, the rings/biners are extra gear that I just don't want to carry.
The pics above show a rig that equalizes like a champ. By doubling the cordalette, I've effectively limited the potential extension, and by knotting it, I've added redundancy. If you want to limit the extension even further, tie one limiting knot on the side opposite the redundancy knot, a la the middle pic. If the anchor points are too spread out for the doubled cordalette to reach, I can use the same old solution we've all been using for ages: extend the individual pieces with runners, a la the right pic. Also notice that I've constructed a lower clip in point. In the pics, I am anchored to what is now the "shelf."
Match it up tradclimbingfool's new acronym, SRELE (pronounced "surreal" :lol:). It's simple, redundant and equalizing with limited extension. Like the "cordalette," it has one knot, one biner, and you can rig it just as quickly. But most importantly, this rig is very versatile, a quality some of the others lack.
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reg
Mar 17, 2006, 6:21 PM
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j_ung: trixi must be out dancing or she'd have your hide for clippin her dinning room set!
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vivalargo
Mar 17, 2006, 6:34 PM
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You guys gotta come up with another name for the "mhabichtlette." Something simple and catchy. "Mhabichtlette" is a bust.
Also, this looks very promising to me, but I suspect it might be a bit thorny to rig in a vertical carck connecting 3 or 4 pieces. Anyone field test this in this configuration??
Also, the quad can be tied in any length you want-no one is saying you have to use a regular cordelette. The 4 strand set up is overkill for many but for those who guide, top rope or climb on sport anchors, when tied on tech cord, the quad is indestructable and very wear resistant which is the reason for the 4 strands. This is a work horse rig, period. And super fast to set up. Try it and you'll immediately understand why it's so good.
JL
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healyje
Mar 17, 2006, 6:37 PM
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J_lung,
Somehow I managed to avoid ever hearing the term "shelf" before and still am not understanding what it is and how you doubled AE rig provides it any more than any other rig. Could you elaborate a bit. As for your single limited and doubled AE rig itself, it is certainly a simple solution I'll grant you that, better I don't know. It suffers the same extension issues already well discussed in the first 15 pages or so. And while I doubt that the extension is that big a deal in your doubled AE rig I'm pretty enamored with the total control over extension provided by mhabict's. That may subside, but for now I still prefer it and am willing to trade a little simplicity for that control, particularly in an anchor that was going to be less than bomber regardless of one's best efforts.
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glowering
Mar 17, 2006, 6:44 PM
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J_lung,
A few issues I see with that setup: I think the limiter knot will effectively kill the equalization. That much cord around the biner will probably bind (as Largo mentioned they discovered in testing) and not equalize well (perhaps 5.5mm would be better).
I think a simpler, similar solution would be to set up two sliding-Ws (triple sliding-Xs) with 4 foot runners (one biner on the bottom of each). I think it would equalize better, and be simpler/faster.
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glowering
Mar 17, 2006, 6:50 PM
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In reply to: You guys gotta come up with another name for the "mhabichtlette." Something simple and catchy. "Mhabichtlette" is a bust.
How about Machete? Or it that too scary, like European Death Knot? :lol:
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hemp22
Mar 17, 2006, 7:23 PM
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Joseph, the Shelf that J_ung is referring to is the point located *Above* the knot on the traditional cordalette setup. i.e. once you set up the cordalette and tie the knot to get your big powerpoint loop, you can also clip in just above the knot. Some people use that location as a "first piece" when leaving they belay on lead, at least until they get another piece in, and others will just use it as a handy place to clip gear for re-racking.
I do think it's a hand place to hang gear to give back to the leader (if you're not swapping leads), but I also think that Mhabricht's rig provides some equally convenient spots to do that.
and I agree w/ glowering that the amount of cord going through the biner on J_ung's rig will probably lead to enough friction that it wouldn't really equalize as well as expected.
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billl7
Mar 17, 2006, 7:24 PM
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In reply to: You guys gotta come up with another name for the "mhabichtlette." Something simple and catchy. "Mhabichtlette" is a bust.
I suspect that Mike suggested hawkette because on a four piece anchor it does sort of have a profile of a raptor. eagle-ette sounds kind of like equalette and indeed it is an extension of same. And raptors in general have a flavor of tenaciousness - worthy in an anchor name.
$0.02
Bill L.
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tradklime
Mar 17, 2006, 7:27 PM
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In reply to: Tradklime, you'll notice that this is similar to what you just posted. Your rig is sweet, but I think it's still too complex. First off, you don't need that special knot -- a single overhand in the middle of a pre-looped cordalette will work just as well. Second, the rings/biners are extra gear that I just don't want to carry.
j_ung, I hear you on the simplicity aspect. The special knot just helps keep the knotted area of the cord limited. I think that having several knots creates additional points that can get bound up and caught on things during adjustment/ equalization. Further, the rings really help keep the adjustment of the rig smooth, all that cord running against itself can create a lot of friction and potential for binding. The other thing the rings help with is having a "power point" that can accommodate multiple biners (that can be clipped easily when weighted). I seem to only do these type of anchors if I'm in a group of 3 or doing all the leading.
Bottom line is that we are all going to have our own preferences, and that's cool because they all involve one compomise or another. They are all better than a traditional cordalette anchor, in my opinion.
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tradklime
Mar 17, 2006, 7:35 PM
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In reply to: In reply to: I agree w/ glowering that the amount of cord going through the biner on J_ung's rig will probably lead to enough friction that it wouldn't really equalize as well as expected. That's what I thought would happen, too, but surprisingly, it didn't bind up at all. It adjusted perfectly in both directions.
Did you try it out fully weighted? Because I've noticed friction issues with a simply "sliding W" with a single spectra sling. Also, JL's drop tests seemed to indicate that even the friction with the simple sliding-x can affect the load distribution.
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vivalargo
Mar 17, 2006, 8:40 PM
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Per the binding or potential binding on Jung's rig--our testing showed that while it might smooth smooth as good Scotch under a few pounds of weight, it might bind when suddenly weighted big time--as in a drop test. I suspect it was the material binding on the aluminum, and this was fixed by using a wide mouthed anodized biner. But you won't know till you test it. That's a lot of material in the mouth you have there, but it might work great--you just can't know a lot till you field and lab test this shite.
Also, since so many anchors are set up in vertical cracks, I would encourage you guys to keep that in mind. if a rig has too many doodads they really get in the way when the lines are strung over each other (as happens in vertical cracks).
JL
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knudenoggin
Mar 18, 2006, 12:33 AM
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In reply to: also this from same poster: "My biggest concern is the reliance on single strands of cord going to each piece. " that's all you have anyway! ie; cordelette rigged ( the old JL way) to three pieces and an 8 to finish at the power point you end up with three loops going to the gear but each loop is one pass over the biner (same as one strand)
In some of the systems presented--i.p. mine & Papounet's, that one strand
could be of stouter material, which comes in more dynamic forms (retired 9mm
climbing rope, e.g.).
But in consideration of the single-strand concern, for use with a cordelette
chopped into two pieces, I presented (on other thread) this.
http://tinypic.com/rldjb7.jpg
The 60cm HMPE "dental floss" slings used mid-level (TWO of these) are in a "dogbone"
orientation, so are double-strand in forming the 'biner-slide "V", the twin cord
making the triangle-closing "spanner" segment between (& forming) the limiter knots
(the Becket hitches).
Belay-end sling IS single-strand: use bomber (12mm HMPE?) sling, or double up
with the skinny stuff, which readily fits 2 per 'biner.
*kN*
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sixleggedinsect
Mar 18, 2006, 2:27 AM
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In reply to: Noticeing all the rigging with clove hitches has got me wondering as to their strenght in a sudden force. Now I've trusted dearly many times in a clove hitch, but I'm just wondering if there is any stats (or anyone in the know) on slippage when there loaded quite suddenly with a good force, or any difference if tied with cord or webbing? Just need to ease my mind, thanks.
clove hitches are used as a tie-in knot for free climbing rope soloing. they have been tested as such by the Real World Lab, and I believe ive read posts by russ walling on this site about dropping loads out of trees onto them, with no problems coming up.
good to go, it would seem.
anthony
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radistrad
Mar 18, 2006, 3:06 AM
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Since when was the sliding x used on anything except for two bomber bolts?
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knudenoggin
Mar 18, 2006, 4:16 AM
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In reply to: In reply to: Noticeing all the rigging with clove hitches has got me wondering as to their strenght in a sudden force. Now I've trusted dearly many times in a clove hitch, but I'm just wondering if there is any stats (or anyone in the know) on slippage when there loaded quite suddenly with a good force, or any difference if tied with cord or webbing? they have been tested as such by the Real World Lab, and I believe ive read posts by russ walling on this site about dropping loads out of trees onto them, with no problems coming up. good to go, it would seem.
But I'd not want to have the Clove h. taking aload w/o further precaution.
Lyon Equipment's 2001 report on life safety ropes (low-elongation) found
that, "on most of the tests with low-stretch rope, the clove hitches slipped
without breaking, at widely varying forces ...", whereas, "with the dynamic
rope (Beal Apollo 11mm) the knots broke on every test at forces comparable
with the overhand knot." (They have a "double overhand" by which they mean
the Overhand loopknot--60%+.)
Now it's worth remarking that they tested using a slow-pull device (typical),
so the results (and for one dynamic rope, rather large) don't necessarily show
behavior of a real fall force. But we're tying off low-elongation cordage when
tying cordelette material--static, if hi-mod 5.xmm stuff. (I'd guess that
slippage increases with diameter of tied object. It's not clear on a quick scan
as to what Lyon tied the clove hitch, but it might have been larger than a 'biner.
In this testing, one can see the danger of transferring some knot into a new
environment.
One can secure the clove hitch in various ways: tie a stopper knot in the end
(e.g., slip-knot); tie a half-hitch & stopper around the loaded end; make
a Collared Clove H..
*knudeNoggin*
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healyje
Mar 18, 2006, 5:16 AM
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Given they've been testing the equalette, and came to the conclusions they have, I'd say John's crew has clearly shown the cloves are in fact holding up better than simply good enough.
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moose_droppings
Mar 18, 2006, 5:44 AM
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In reply to: Given they've been testing the equalette, and came to the conclusions they have, I'd say John's crew has clearly shown the cloves are in fact holding up better than simply good enough.
Good point
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glowering
Mar 18, 2006, 6:22 AM
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moved content to pg. 50
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justthemaid
Mar 18, 2006, 3:37 PM
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In reply to: You guys gotta come up with another name for the "mhabichtlette." Something simple and catchy. "Mhabichtlette" is a bust.
I agree. When I made up "mhabichtlette" I was being totally facetious. I didn't intend it for real use. (Cracks me up you guys keep using it).
How about "Mike's slider" for now?
In reply to: Also, this looks very promising to me, but I suspect it might be a bit thorny to rig in a vertical crack connecting 3 or 4 pieces. Anyone field test this in this configuration? JL
I've done my preliminary "trellis test" in the vertical and with odd placements. It actually works just fine. You sometimes have to add slings to the longer arm(s) to get the power-point bight where you need it, so it is a little harder than in the horizontal.(But then again- you frequently add slings to vertical set-ups regardless of what system you are using. )
With 3 placements in a vertical, I'm still trying to figure which arm should be the "odd" (no biner) arm. You save a lot of cord if the odd arm is the longest (top) arm.
I'll try to get outside and throw some actual body weight on this set up this weekend.
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billl7
Mar 18, 2006, 5:28 PM
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How does one tie the knot below in the picture labeled "CharlesJMM"? It looks like the knot in Joseph's rig for which I saw someone else's note about how to tie: double over a bite and tie a figure eight with the 4 strands. But that leaves 4 strands coming out top and bottom while the CharlesJMM knot appears to have 2 strands on the bottom and 4 strands (2 loops) out the top. Are my prescription lenses out of date? :D
Bill L. http://www.cs.unm.edu/...les_special_knot.jpg
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knudenoggin
Mar 18, 2006, 9:53 PM
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In reply to: How does one tie the knot below in the picture labeled "CharlesJMM"?
be tying a bowline using a bight for the end--for the rabbit-out-of-hole,
aournd-tree, & back-into-hole part--which bight-end would serve for the
short eye.
With that patterned rope, it's hard to discern what the CharlesJMM knot is,
but I"ll guess that it's a double-eye Fig.8 (don't usually find exotic knots here),
carefully adjusted to size the "bunny ears" appropriately to this task.
*kN*
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charlesjmm
Mar 18, 2006, 11:27 PM
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Edited to reduce picture size.
In reply to: How does one tie the knot below in the picture labeled "CharlesJMM"? It looks like the knot in Joseph's rig for which I saw someone else's note about how to tie: double over a bite and tie a figure eight with the 4 strands. But that leaves 4 strands coming out top and bottom while the CharlesJMM knot appears to have 2 strands on the bottom and 4 strands (2 loops) out the top. Are my prescription lenses out of date? :D Bill L.
Here´s an illustration of how to tie the Double Figure 8. From this configuration, to create uneven loops you simple take in some of the cord of one loop which will feed the other one.
You could also obtain a similar result with a Bowline on a bight.
http://i49.photobucket.com/...8andBowLineBight.jpg
CharlesJMM
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fingertrouble
Mar 20, 2006, 8:42 AM
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Inclement weather this weekend prevented me from skiing, climbing, or addressing my numerous unfinished home improvement projects, so I thought I'd spend some time in my garage looking into one of the underlying issues of this thread: sliding friction at the master point of anchors.
Warnings: Me: my academic and professional careers have involved making, analyzing, and reporting sensitive scientific and engineering measurements, and I'm acquainted with the stick/slip and slide rate issues when measuring friction. I didn't do drop tests or attempt any kind of abrupt loading. I can no longer dead lift a Volkswagen like I could in grad school so I didn't attempt to simulate fall forces. What I did was make a number of 2-placement anchors in a consistent geometry using a variety of materials, hang a heavy weight at the master point, and use an accurate spring scale to measure the force required to pull the master point sideways through its equilibrium position (referring to this force as indicative of friction, in this discussion). I didn't make enough measurements to do statistical studies (no standard deviation, no chi squared tests, none of that), but if I had to guess I'd say the standard error would be maybe 20%. No observations were earthshaking or inexplicable. If these warnings make you think such measurements would be useless, not germane to this thread, or misleading, now would be a good time to stop reading.
Otherwise, here's what I observed.
I set up 3 different anchor designs: the sliding-X, the 2-anchor equalette, and the "troublette," which is a name I'm using for discussion purposes for the anchor in this illustration from my book, The Mountaineering Handbook:
http://i2.tinypic.com/rab134.jpg
The troublette supports the main locker by two strands, but John Long has posted on this thread that strands in good condition simply do not break (with any anchor design). The troublette can be made backed-up by clipping another biner, not necessarily a matching locker, from the unused main strand to the main locker or even to the rope; the strands between the limiter knots don't have to be equal (a significant benefit, as it appears). The sliding-X and the equalette can be configured with one limiter knot, but the troublette cannot.
* Normalizing to the sliding friction of the sliding-X, I measured the sliding friction of the equalette to be about half that. The sliding friction of the troublette measured about half that of the equalette (1/4 that of the sliding-X), which is what you'd expect just by looking at their designs. This was true will all the soft materials I tested. These observations refer to an equalette without limiter knots. Tying limiter knots in the equalette decreases the measured sliding friction. I interpret this to reflect the difficulty of tying limiter knots that create perfectly equal length strands between them (in their final position as they support the carabiners, necessary for perfect force balance at the master point) and perhaps to irregular orientation possibilities of the two identical lockers. This is another illustration of the dictum already brought out, that perfect equalization requires cord/webbing slip around the anchoring carabiner and that limiter knots prevent this. I didn't test it, but likely a sliding-X with limiter knots would have the same issue. In other words, limiter knots tend to make the equalette perform more like a troublette, which is good in terms of reducing sliding friction but not in terms of balancing the loads on the two strands.
* I could not resolve a difference in the sliding friction of 11/16 (18 mm) climb spec webbing and 7 mm accessory cord, in any of the anchor configurations.
* There appeared to be a reduction in sliding friction going from 7 mm cord, to 6 mm cord, to 5.5 mm Tech Cord, but the effect, if there, was small in all 3 configurations.
* I measured a significant decrease in sliding friction using Spectra/Dyneema webbing, compared to nylon. The difference was almost a factor of 2, meaning that a sliding-X with Spectra/Dyneema webbing would perform almost the same as an equalette made with 11/16 nylon webbing or 7 mm cord. I question whether limiter knots or hitches tied in Spectra/Dyneema material would hold satisfactorily.
* I could not resolve a difference in the sliding friction in any anchor design between ordinary 1/2" Spectra/Dyneema webbing and a Mammut 8 mm Dyneema dental floss sling.
* I did notice an improvement in sliding friction when using a "wide mouth anodized pear biner," compared to non-anodized HMS/pear lockers (which had apparently larger rope bearing radii), but I tested this only with the sliding-X and troublette because I didn't have two matching anodized HMS/pear biners with their anodizing intact. While the effect was noticeable, it was near the resolution limit of my testing.
* Presumably, lower sliding friction is better, because that will allow better balancing of forces during the instant of peak fall force, thus better achieving the design objectives of the anchor, but applying these observations to or making conclusions about any anchor design when impacted by real fall forces is outside the scope of my inquiry this weekend.
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healyje
Mar 20, 2006, 8:55 AM
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In reply to: The sliding-X and the equalette can be configured with one limiter knot, but the troublette cannot.
The equalette wouldn't be an equalette without both limiter knots...
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