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glowering
Aug 28, 2006, 6:35 PM
Post #26 of 45
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I switched to cordelettes when the 5.5mm spectra cord came out. It seemed a quick, easy way to build 3 pieces anchors with light, non-bulky gear.
The sliding X thread brought up a number of good ideas as a replacement to the old static knotted cordelette. But when I read the report on the testing of spectra vs. nylon cord, I decided to ditch the spectra cord.
So I'd have to go to 7-8mm cord for a cordelette types system. That's a lot of bulk and weight compared to a couple slings.
A couple disadvantages of all the equalizing cordelette systems. 1. I don't want to tie a number of clove hitches or other knots in each anchor, too time consuming. 2. Many partners won't be familiar with them. 3. They are more difficult to inspect. 4. Most don't fully equalize 33/33/33 anyway.
So I just use a pre-tied sliding X with limited knots in a 48" sling. I keep one strand of the X that goes around the biner a little loose, so it won't bind and reduce equalization. If I want a third piece I just use another sling with a little slack to my master powerpoint biner.
On many anchors this means NO knots. The fastest anchor possible. Equalizes very good on two pieces (all I need 99.99% time, although I often put in a third piece for piece of mind). Redundant and limited extension with a single 48" sling.
If I did run into a very rare situation where I wanted good equalization on 3 pieces I would probably rig a sliding W (3 point sliding X) and use my rope as a backup.
The new-school sliding X is a similar solution. A good idea, but a couple reasons I haven't switched over to it: 1. Partners won't be familiar with it. 2. It requires untying and retying 1 knot at every anchor.
Here's my last post in the sliding X thread:
In reply to: I've searched for the link to the pictures of the sliding x with limiting knots in the outer legs and can't find it. Can anybody post it, please?
Here's some photos of a sliding X with limiter knots.
It pays to dress the limiter knots so they are clean.
I leave it pre-tied and almost never adjust the knots. If one side is too long I'll throw an overhand or 8 in that arm to shorten it. Or if one side is too short, I'll extend to that piece with another sling.
For racking I just leave my master point big locking caribiner clipped in the X, then twist the arms and clip the arms to the master biner.
I have it tied so that the strand that circles the biner has a little slack in it, then there is no binding so it get's the best possible equalization, but there is still redundancy (so I'm not dependant on a single strand of a sling).
I'll clip this to two bolts or two pieces of pro for my anchor. If I want a third piece of pro in my anchor I just use a sling from that piece to my master point caribiner with a little slack in it.
I find this is very fast, often faster than a cordelette and I get the best possible equalization from two pieces with the least amount of gear.
http://img249.imageshack.us/img249/748/x2dr.jpg
Here's the max seperation:
http://img144.imageshack.us/img144/8400/xfar8tq.jpg
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norushnomore
Aug 28, 2006, 10:31 PM
Post #27 of 45
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I think there are flaws with your setup:
1. Limiter knots are not of much use on spectra slings, they will slide all way to the end producing heat and weakening your sling thus compromising your anchor and not limiting extension.
2. Two slings on the bottom will bind onto each other and will not give you dynamic equalization you are hoping for (search for an old alpine equalizer thread where inventor describes his drop tests that lead him to his design with the rings).
3. No good for a trad anchor (covers only 2 pro pieces).
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glowering
Aug 29, 2006, 5:27 AM
Post #28 of 45
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There's flaws with all setups. But to address your concerns.
1. Spectra slings are not a good idea in any anchors IMO.
2. The slings on the bottom don't bind. Here's a photo (still poor though) that shows the modified sliding X a little better. I give the strand that goes around the biner a little extra slack, so the biner runs on the single strand that doesn't wrap around it, the other strands hangs a little loose and out of the way. I suppose it could still get trapped under the other strand and bind, but I haven't seen it happen yet after setting it up this way on many real anchors.
http://img293.imageshack.us/.../3371/loosex26yq.jpg
3. This will equalize as good as possible on two pieces. That is all the strength I need for a trad anchor. I'll usually add a third piece, not equalized, purely as a back up. In the highly unlikely situation that I'll need equalization on 3 pieces I can use something else.
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slacklinejoe
Aug 29, 2006, 2:12 PM
Post #29 of 45
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In reply to: I think there are flaws with your setup: 1. Limiter knots are not of much use on spectra slings, they will slide all way to the end producing heat and weakening your sling thus compromising your anchor and not limiting extension. 2. Two slings on the bottom will bind onto each other and will not give you dynamic equalization you are hoping for (search for an old alpine equalizer thread where inventor describes his drop tests that lead him to his design with the rings). 3. No good for a trad anchor (covers only 2 pro pieces).
Do you have anything to backup your claim on #1?
#2. The new study by JL pointed out ways of reducing binding to better the distribution of the load. While not perfectly 50/50 just using an anodized biner with the correct shape reduced binding significantly.
For #3, you just use a seperate sling to the equalize an arm to the 3rd piece - a throw back to the original anchors book by John Long will show this in proper use.
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el_jerko
Aug 29, 2006, 2:43 PM
Post #30 of 45
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What exactly is the proper shape for biner?
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microbarn
Aug 29, 2006, 3:13 PM
Post #32 of 45
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pear shaped
HMS style biner
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cracklover
Aug 29, 2006, 4:02 PM
Post #33 of 45
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I've played with several of the anchors in the field. I've settled on just a few that I use.
At the times when I use a cordelette, I'm now almost exclusively using one configuration: the Mooselette. To me, it was the clear winner in all cases except where there's potential for rockfall, in which case I use the CharlesJMM anchor (or two crossed slings).
The mooselette equalizes beautifully, and is extremely quick to set up, especially if you leave the two knots in it, which I do.
I've used the Mooselette dozens of times, have slept on a porteledge on it, etc. Here's what it looks like in action up on Yellow Ridge in Eldorado Canyon:
http://i26.photobucket.com/.../gostriker/anch3.jpg
I have more photos of it in action. If needed, I'm happy to load them up and post them here.
GO
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ericbeyeler
Aug 29, 2006, 4:58 PM
Post #34 of 45
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In reply to: If I did run into a very rare situation where I wanted good equalization on 3 pieces I would probably rig a sliding W (3 point sliding X) and use my rope as a backup.
Can you explain how you would equalize the sliding W?
I would not feel comfortable with an anchor of only 2 pieces of gear. Not enough redundancy for something that has a (relatively) higher chance of failing. I would trust 2 bolts, or 1 large tree. But something rated to only 2000 lbs with a placement that may not be 100% bomber... Say the failure rate for 1 placement is 1 in 100. That means two pieces are 1 in 10,000. Much better, but three pieces puts that at 1 in 1,000,000 which gives me much more confidence. You also have to take into account that if the pieces are truly equalized (unlike the cordelette), the chance for any one failure decreases because each piece only bears a part of the load.
Anyway, enough rambling. Thanks to all who have chimed in so far. I will try to get a picture of the duoglide/mhabicht setup in action this week and post it.
Eric
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glowering
Aug 29, 2006, 8:31 PM
Post #35 of 45
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In reply to: Can you explain how you would equalize the sliding W?
The sliding W will equalize itself as long as you don't put limiter knots in it. Use a large anodized biner to reduce friction. I think the sliding W has the least friction of all 3 piece equalization setups, so equalizes the best.
There is a thread "Solution to the John Long Anchor Challenge" or similar name, that demonstrates this idea. Except the author says use two cordelettes, one as a sliding W, and one as a static tied cordelette as the backup/extension limiter, while I would use a double length webbing sling or cord (preferably cord since I think webbing would probably bind easier) as the sliding W (because I don't carry cordelettes anymore) with extensions to the pro if needed, and clove hitch my rope to the pieces as the backup/extension limiter.
In reply to: I would not feel comfortable with an anchor of only 2 pieces of gear. Not enough redundancy for something that has a (relatively) higher chance of failing. I would trust 2 bolts, or 1 large tree. But something rated to only 2000 lbs with a placement that may not be 100% bomber...
I actually feel more comfortable with 2 pieces of my own gear (with bomber placements) than two bolts. I know the history of my gear, I don't know if a bolt was overtorqued when installed and ready to shear, or is rusty inside.
On a big ledge, with a good stance I only use two pieces of bomber gear. On a hanging belay, etc. I use two pieces of bomber gear with a limited knot sliding X (with a modified powerpoint to reduce binding and improve equalization), then I'll back that up with another piece of bomber gear with another sling to the powerpoint biner. If I run into a belay with non-bomber placements I could do a sliding W for 3 pieces (with a backup), or two sliding Xs joined with a third sliding X for 4 pieces.
The sliding X thread was great in that it got us all thinking about our assumptions and trying new things. When it was pointed out that the static tied cordelette didn't eqaualize, JL threw out the challenge to find a replacement that actually equalized and had similar attributes: uses a small amount of familiar gear, quick, KISS. A lot of good ideas where presented but non were truly KISS IMO.
I used the static tied cordelette for about 95%+ of my anchors from 2000 until earlier this year when it's shortcomings were brought to light. In looking for a replacement I wanted something that could stay on my rack and still be used 95%+ of the time. I tried all the various cordelette based solutions, but none were KISS. The need to fully equalize among 3 pieces is so rare in my climbing, I just don't see the need to use an elaborate solution all the time. As mentioned, the static tied cordelette still works in most anchors when all placements are bomber, however I still like the idea of equalizing the force on at least two pieces for true redundancy. (two piece in series, i.e. one blows after the other, are backed up, while two pieces in parallel, i.e. equalized, is true redundancy).
Even the duo-glide (equalette) is more than I want to deal with. I don't want to tie 3 clove hitches for every anchor. And I don't want to use 5.5mm spectra cord anymore (actual failure figures are alarming) or carry 7mm cords.
My spectra cordelettes are destined to become slings at rap stations, and I'll probably start carrying two 4' 7mm cord slings for trees, bail slings, rescue, etc, in addition to the 2' cord slings I already carry for emergencies.
The solution for binding of the powerpoint on the duo-glide is to use two locking biners on two strands for the powerpoint, but I like to use 1 big locker as my Powerpoint (for Trad), to which I clip another locker with my clove hitch, a locker with my partners clove hitch, and a locker for the belay re-direct. I don't want to put those 3 lockers through 2 lockers for the powerpoint, kind of defeats the purpose of an easy to clip in and out (even when weighted) powerpoint. So I use my modified sliding X, but it's never been tested, so use at your own risk.
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billl7
Sep 4, 2006, 11:18 PM
Post #36 of 45
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In reply to: In reply to: well, now that i think about, it seems to me that even 7mm nylon is problematic. 7mm perlon is only rated to 9kN, so each arm of the new school sliding x starts off at 9kN, but there are several knots in the cord which weakens it. the duoglide suffers from the same problem. On top of all of that, the weakest point will likely be the clove hitch. If the cord breaks there, redundancy introduced by the clove hitch is lost.
My perlon is rated to 11 kN. Assuming 30% total loss on a side for the limiter knot and/or bend around the locker, I come up with a remaining total "strength" for the anchor of ~30 kN (~6700 pounds). So I don't see an issue at the limiter knots and below. But ...
If the direction of pull is unexpected then probably 2 pieces take the load. In that case and looking just above the limiter knots, all the initial load goes through 2 strands and 2 clove hitches. Assuming 30% reduction on a side for 1 clove hitch, we are now at ~15 kN or 3,388 pounds total anchor "strength."
Does that make folks uncomfortable? Maybe only 30% loss for a clove hitch falls a little short?
Anyway, if a clove hitch breaks then isn't the other clove hitch on that side of the anchor still intact? Granted, if there is enough energy to break both hitches on one side or break 1 and cause the other to slip far enough to release then we are toast if the other side of the anchor likewise failed. I'll venture that total failure due to cordage breakage seems adequately unlikely.
Am I missing something?
Bill L
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billl7
Sep 5, 2006, 12:59 AM
Post #37 of 45
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For those who have worked a bit with the duoglide/equalette, what do you use for the power point or main access point? No right or wrong answers in my view at this point.
For instance and for swapping leads, the 1st at the anchor could tie in with the rope via a bowline on a bight locked into both lockers. Then the second merely locks into the loops of the bowline, gear is swapped, and the second (now the leader of the second pitch) unclips from the bowline.
For leading in blocks, each could anchor/unanchor using their knotted bight of rope by individually (and carefully) unlocking and relocking the 2 lockers.
Another idea for leading in blocks is to put a couple loops of webbing through both lockers to serve as the main point for clipping into the anchor.
Thoughts? Alternatives?
Bill L
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ericbeyeler
Sep 6, 2006, 2:33 AM
Post #38 of 45
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In reply to: For those who have worked a bit with the duoglide/equalette, what do you use for the power point or main access point? No right or wrong answers in my view at this point. For instance and for swapping leads, the 1st at the anchor could tie in with the rope via a bowline on a bight locked into both lockers. Then the second merely locks into the loops of the bowline, gear is swapped, and the second (now the leader of the second pitch) unclips from the bowline. For leading in blocks, each could anchor/unanchor using their knotted bight of rope by individually (and carefully) unlocking and relocking the 2 lockers. Another idea for leading in blocks is to put a couple loops of webbing through both lockers to serve as the main point for clipping into the anchor. Thoughts? Alternatives? Bill L
I put small loops of runners through the two power point biners and clip into the loops. It makes it cleaner to attach everything like that. Then each climber can attach / detach easily without affecting anything else.
Eric
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dingus
Sep 6, 2006, 3:12 AM
Post #39 of 45
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In reply to: 1. Limiter knots are not of much use on spectra slings, they will slide all way to the end producing heat and weakening your sling thus compromising your anchor and not limiting extension.
You speak as if this were an absolute given. Got anything to back it up? Certainly doesn't jive with my experience using spectra slings on climbs and such.
DMT
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beesty511
Sep 6, 2006, 8:59 PM
Post #40 of 45
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In reply to: 2. The slings on the bottom don't bind. Here's a photo (still poor though) that shows the modified sliding X a little better. I give the strand that goes around the biner a little extra slack, so the biner runs on the single strand that doesn't wrap around it, the other strands hangs a little loose and out of the way. http://img293.imageshack.us/.../3371/loosex26yq.jpg
In reply to: In reply to: I think there are flaws with your setup: 1. Limiter knots are not of much use on spectra slings, they will slide all way to the end producing heat and weakening your sling thus compromising your anchor and not limiting extension. Do you have anything to backup your claim on #1?
i don't see how. maybe in an idealized frictionless environment. but in your picture, you have 5 strands running over the master point biner, as well as 4 strands of cord running over two biners higher up. that isn't going to equalize properly because all of the friction produced by the cord sliding against the biners will keep the impact forces from distributing equally to each piece of pro.
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dingus
Sep 6, 2006, 9:29 PM
Post #41 of 45
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http://www.trango.com/prod.php?id=19
I'd much sooner go with this rig (have used my buddy's, works as advertised) than I would frig around with 6 carabiners, cloves, overhands and all that other complicated procedure. Their very complexity instantly rules them out imo.
But then again, I think most of this equalization and no extension worry is unfounded bullshit. I don't think its important at all for a large % of the routes I climb and only marginally important for a lot of the others. I think only occasionally is it truly an important thing to worry over.
I'd be a LOT more worried about that tired partner of mine up there, trying to rig one of those complicated 'gotta equalize the world' setups, perhaps in the fading light of day.
A simple cordelette is far preferrable, from a pilot error standpoint.
IMO of course.
DMT
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glowering
Sep 7, 2006, 8:49 PM
Post #42 of 45
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In reply to: the problem with that setup is that all of the force goes on one strand. 7mm perlon is rated to about 9kN, and you lose up to a 30% of that when you tie a knot in it. so the weight bearing strand may only hold about 6kN. is that enough? if the force breaks the first strand, it can then impact the loose backup strand and break it.
Like I mentioned in my other post I've moved from cord in my anchors to webbing, that photo was just to illustrate a concept better.
Probably the only time you are going to face forces high enough to worry about is a leader fall on the anchor. In that case you can redirect the belay off the anchor with a screamer, or belay directly off your waist with a good stance (tie in with the rope).
In reply to: 1. Limiter knots are not of much use on spectra slings, they will slide all way to the end producing heat and weakening your sling thus compromising your anchor and not limiting extension.
Limiter knots in the middle of a sling aren't going to slide to the end. I still wouldn't use spectra slings in an anchor but the forces on a limiter knot (an overhand tied in the middle of a sling) are just going to cause the knot to get tighter, not slide.
Dingleberry is right. How often are we going to need anything special? With 3 bomber pieces most things work fine: static tied cordelettes, sliding Xs, clove hitch to each piece, etc. The only time you need equalization on more than two pieces is if you have 3 non-bomber pieces and you can't place you first lead piece from the belay. I've never faced that, but if I did I'd use a 3 way sliding X (W) for the least friction and hence best equalization possible, and back it up for non-extension seperately.
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cracklover
Sep 8, 2006, 4:30 PM
Post #43 of 45
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In reply to: i don't see how. maybe in an idealized frictionless environment. but in your picture, you have 5 strands running over the master point biner, as well as 4 strands of cord running over two biners higher up. that isn't going to equalize properly because all of the friction produced by the cord sliding against the biners will keep the impact forces from distributing equally to each piece of pro.
Two responses.
First, since this is a thread about what happens in practical use, let me share what my experience has been. in practice, I have found that it does!
In normal use, only one of those five strands is actually moving through the powerpoint, so unlike some of the other rigs in which multiple strands are moving in opposite directions at various speeds, the movement here is very clean and singular. To assure that there's plenty of room, I have been using an HMS or Pear, with the big end up.
Okay, so that's the deal when nothing rips. What happens when something does rip? When an outer piece is removed, again only one strand slides, so you get clean movement. When the middle piece is removed, there is essentially no sliding at all!
Second response. In principle, I agree with your argument! While I know from experience that the loads distribute, I cannot know exactly how efficiently the sides equalize in real-time. This would take sophisticated equipment to answer.
Jim at Sterling, who ran the tests for JL, could do it, but this takes time, and time is money. I figured that the only person with the pull (no pun intended) to get some of the new (and apparently superior) anchor setups tested for force distribution is JL. I suggested as well as I could to him in the original thread that this would be a huge service to the community. I have also done so in person to Jim, since then.
But really, John has a path he's already gone down, and a book that's basically already published, so I can understand that this would really seem like no more than an unwelcome distraction to him. Especially since I'm just some faceless nobody posting on the internet. So I don't expect it ever to happen.
Short version - the Mooselette clearly distributes the forces well. Whether it equalizes them is anybody's guess. But for now, well distributed forces is good enough for me.
GO
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jimdavis
Sep 8, 2006, 11:38 PM
Post #44 of 45
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In reply to: In reply to: As long as you don't lost spectra for this set up... Saw an article recently which talked about how spectra knots fail at much much lower forces than nylon. well, now that i think about, it seems to me that even 7mm nylon is problematic. 7mm perlon is only rated to 9kN, so each arm of the new school sliding x starts off at 9kN, but there are several knots in the cord which weakens it. the duoglide suffers from the same problem.
Can you guys think of any failures of 7mm nylon or spectra sling material, that wasn't due to sharp edge cuts?
I can't.
Cheers,
Jim
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patto
Sep 9, 2006, 12:44 AM
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I use the cordalette.
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