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walkonyourhands
Nov 2, 2007, 2:39 PM
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Sorry if that's been covered before, I couldn't find a thing.
Over the last year, I've heard quite a bit about some new studies by the German Alpine Association that seem to show (the study is to be published in the next couple weeks) limited real-world equalizing abilities of the sliding -x. Their new porposal seems to be the following:
The pic was taken from a thread on an Austrian board and is not mine. The thread is: http://www.bergsteigen.at/.../Thema.aspx?ID=57091
The 'eye' that is clipped to the lower bolt ist formed using a double bowline and is meant to be the power point. The clove hitch at the other bolt shortens the sling so much that it takes a part of the weight. (kind of pre-equalizing; prolly not short enough in the pic)
Of course, it's only for two-bomber-bolt-belays.
Last winter, a friend of mine who is a guide showed me this method and uses it almost exclusively himself when the belays are bolted. Meanwhile, I prefer it over most other methods, too, if the circumstances allow it. It's especially nice if you're a party of three as it is a clean setup.
You propably know that us Euros don't use the cordelette/equalette at all, so this seems to be the next innovation in our guidebooks.
What I like especially with this setup is that I can carry it pre-tied around my shoulder with all necessary 'biners clipped to it. No power-point-tieing required at the belay.
What's your opinion on that?
btw...one more thing came to my mind...
How about tieing a sling parallel to your belay loop with a double bowline, resulting in a plenty strong second donut with a self-belay sling included? No more girth-hitching a sling to your harness? Backup for the belay loop? (To me unnecessary, but well-discussed on rc.com)
Cheers for your comments!
edited the title
(This post was edited by walkonyourhands on Nov 3, 2007, 3:25 PM)
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j_ung
Nov 2, 2007, 2:45 PM
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Most 2-bolt anchors I see have them side by side, not staggered atop each other like here. In such a case, all the weight would be on the bolt holding the powerpoint, with potential for a swinging extension if that bolt fails. Looks pretty good, though, for the bolt configuration in your photo.
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petsfed
Nov 2, 2007, 3:44 PM
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This requires too much consistency in bolt placement, and also fails if there are no bolts. Ergo, good to know, but not supplanting anything else.
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climbingaggie03
Nov 2, 2007, 3:51 PM
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I don't understand how the upper bolt is taking any more load than what is put on it when it is clove hitched, is it equalized? or is it more of two bolts basically in series, but most (probably at least 95%) of the load looks like it is on the lower bolt.
When I know that I'm going to be dealing with 2 bolt anchors, I take a double length sling, and set it up to be a sliding X, then tie knots to limit the extension, clip a carabiner to either end, clip the carabiners to each other, and then carry it over my shoulder.
It carries great, works well as long as the bolts aren't too different, if they are I can throw a QD on the upper bolt or something.
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reg
Nov 2, 2007, 3:57 PM
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there's a small amount of potentail extension for sure. if bottom bolt fails then everybodys hangin on one strand of the runner. i would have put the stitching after the clove but i wouldn't have used that config anyway. i think an x would work equally well as this rig. better if loaded to the right. i don't see any benifit - is this a troll?
(This post was edited by reg on Nov 2, 2007, 3:58 PM)
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walkonyourhands
Nov 2, 2007, 5:01 PM
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j_ung wrote: Most 2-bolt anchors I see have them side by side, not staggered atop each other like here. In such a case, all the weight would be on the bolt holding the powerpoint, with potential for a swinging extension if that bolt fails. Looks pretty good, though, for the bolt configuration in your photo.
It actually works pretty well on two side by side bolts. It you pull it tight enough, the knot will actually be pulled towards the middle between the two bolts, thus you achieve an equalization similar to the sliding x.
In reply to: This requires too much consistency in bolt placement, and also fails if there are no bolts. Ergo, good to know, but not supplanting anything else.
It's less work than setting up a cordelette, that's a good point for lazy me...
I've never had concerns about the sliding x as long as the bolts are fine, but I like the clean attitude of this setup and the fact that not the whole party depends on one power point locker.
In reply to: is this a troll?
Good point, but....no! 
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sweetchuck
Nov 2, 2007, 5:32 PM
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Clean attitude indeed! How is this rig redundant though? If the sling is cut below the bottom biner then that's it. the sliding x needs two strands to be cut to fail. Also, if the bolts are further apart and better aligned horizontally it seems to me that any force the top part does take will be multiplied some.
sc
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maldaly
Nov 2, 2007, 5:44 PM
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That's the coolest thing I've seen for a while. I think I'd tie that upper clove hitch as a double to add redundancy. Plus, it would give you another good loop to clip in to. Don't forget, lab tests by John Long at the Sterling test facilities, have show that shock-loading from extension is so low in climbing situations that it's almost unmeasurable. The main worry you have from extension is it will upset your stance and could cause you to stop belaying.
Mal
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wannabe
Nov 2, 2007, 5:50 PM
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It looks like a good alternative to a cordalette setup, with an exception, get your climbing rope directly on on of those bolts! A failure of the sling would have bad consequences and it is very simple to back it up with the rope.
I feel the same way about the cordalette setup, always tie in with the rope on one of your pieces.
Doesn't everyone do this? They should.
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reg
Nov 2, 2007, 5:52 PM
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sweetchuck wrote: ... the sliding x needs two strands to be cut to fail. sc
how u figure that? the SX protects you if one legs gear or bolt fails - cut any part of the sling and ur gone
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moose_droppings
Nov 2, 2007, 6:07 PM
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^^
He must mean a sliding X with limiter knots.
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reg
Nov 2, 2007, 6:12 PM
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wannabe wrote: It looks like a good alternative to a cordalette setup, with an exception, get your climbing rope directly on on of those bolts! A failure of the sling would have bad consequences and it is very simple to back it up with the rope. I feel the same way about the cordalette setup, always tie in with the rope on one of your pieces. Doesn't everyone do this? They should.
i agree - probably the safest way to anchor yourself
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shimanilami
Nov 2, 2007, 7:30 PM
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Something about the assymetry of it throws me off. It looks like you're basically anchoring to a single bolt, with a second bolt as a back-up. As sound as it may be, I don't see myself using it.
I definitely like Mal's idea of doubling the upper clove hitch, though, if I were to use that set-up.
On another note, how does one rap off that anchor? Do you only use the one bolt? It seems to me that if the bolts are staggered in this way, then the upper bolt should have chains.
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walkonyourhands
Nov 2, 2007, 8:37 PM
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maldaly wrote: That's the coolest thing I've seen for a while. I think I'd tie that upper clove hitch as a double to add redundancy. Plus, it would give you another good loop to clip in to. Don't forget, lab tests by John Long at the Sterling test facilities, have show that shock-loading from extension is so low in climbing situations that it's almost unmeasurable. The main worry you have from extension is it will upset your stance and could cause you to stop belaying. Mal
Nice to hear such a comment from you, Mal.
Do you know (and I think you do) how likely dyneema slings are to slip in a shockload situation? 'cause if you tie that clove as a double (and if I get you right) and the main bolt fails, the tail might just slip through and you go for a flight....hypothetically
Would nylon be a beter choice here?
In reply to: Something about the assymetry of it throws me off. It looks like you're basically anchoring to a single bolt, with a second bolt as a back-up. As sound as it may be, I don't see myself using it. I definitely like Mal's idea of doubling the upper clove hitch, though, if I were to use that set-up. On another note, how does one rap off that anchor? Do you only use the one bolt? It seems to me that if the bolts are staggered in this way, then the upper bolt should have chains.
Well, if the bolts aren't too far apart (which would create a larger angle and thus load multiplication), you can kind of equalize the whole thing by tensioning the leg to the clove.
I don't know if that's supposed to be a rap anchor, as mentioned, the photo is not mine.
I also tried using an overhand instead of the clove hitch...that would add the second strand to the system, but I'm not sure how it would perform if the other bolt failed.
I'm sure, Chris Semmel, who suceeded Pit Schubert in the DAV Safety Commitee, will explain further detail in his study...I'll try to post an excerpt when I can get my hands on it (might take some time)
Any idea about the belay loop thing? It's only hypothetical so far as I'm concerned about slippage here, too
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maldaly
Nov 2, 2007, 8:55 PM
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Before I used the double clove setup I'd test it pretty throrughly. I've never seen dyneema slip. I've tested all then knots you're likely to use, bad knots, wet knots etc. The old Spectra used to slip but there's more nylon in the Dyneema blends plus, they weave a solid thread of it along the edges. I think that's why it holds well.
When I pull test a clove hitch around a carabiner, the Dyneema fails at the throat of the knot at between 16 and 18kN. If I use a double strand the carabiner breaks.
Mal
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rgold
Nov 3, 2007, 8:14 PM
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Walkonyourhands, I hope you can find the time to post links to some of the testing information. (Or better, if you could translate it for us!) The tests on the equalizing ability of the sliding X that I've seen have come to contradictory conclusions, and the results may well depend on whether the test is a slow pull test or a dynamic one (with equalization coming out better in the dynamic test).
I also think that caution is advisable with respect to the Sterling lab tests about the impact loads imposed by extension. Those tests were done as drop tests with a relatively long length of rope that aguably could be effective in absorbing the extra energy of a short extension in the anchor rigging (the extension, being small compared to the length of rope, produces only a very small change in the fall factor). When, more realistically, the same impact has to be absorbed by a climber's tie-in that is approximately the same length as the extension itself, we might possibly see the much higher loads associated with a factor-1 fall. For this reason, I wouldn't be comfortable asserting that extension has negligible effect until some tests can be done that model the belayer tied in short and catching the falling leader.
As for the "new" rigging set-up, I have the usual (for me) set of observations:
(1) On good bolts as pictured, equalization is really of little concern. Any method of tying in that will allow one bolt to back up the other by sharing the load equally or just sequentially really should be fine. I agree with Mal that the double clove-hitch is the way to go at the upper bolt.
(2) If the bolts are suspect, then genuine equalization becomes important and I don't think there's anything better than the equalette for that, but suspect bolts at belays on popular routes are getting pretty rare nowadays.
(3) Getting back to good bolt anchors, it is hard to beat sequential clove-hitching of the anchors with the climbing rope for speed, security, and effectiveness. If climbing with two ropes, one rope clove-hitched to each bolt and you're done. You only need an installed power point if the leader is going to lead more than one pitch in a row.
(4) Ok, Ok, nowadays belaying the second directly off the anchor seems to have become the norm and so the simple methods of (3) don't work. If using two ropes, one can immediately gather the strands hanging from the bolts, tie a figure eight, and use that for installing the belay device. If using one rope, then clove to the first bolt, tie a butterfly knot power point, and clove to the second bolt.
In view of the additional strength, security, and energy-absorbing capabilities of direct rope tie-ins, there are almost no good arguments, in my opinion, for using independent slings of any type unless the leader is going to lead multiple pitches in succession or the route is a big wall. In fact, the only arguments I've heard that carry any weight have to do with belay escape and rescue scenarios, which are decidedly more complicated if the belayer is tied directly to the anchor. My personal feeling is that most of these scenarios are hypothetical exercises with little or no practical utility, so the additional complication does not seem to me to weigh heavily in the decision process.
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ja1484
Nov 3, 2007, 10:24 PM
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rgold makes wonderful insightful points per usual. My perspective re: two bolt anchors:
1) If the bolts are bomber and you're swapping leads, I prefer to tie off a double-loop fig-8 on a bight and clip a loop to each bolt. This not only secures the anchor quickly, directly out of the rope, and with a minimum of gear and fuss, but it also secures the leader as well. Once in place, a directional 8 tied into the second's end of the line allows for a quick direct-belay attachment point at the anchor.
The business is adjusting length of the knot away from the harness - too long is not a problem, as shorting things with a clove hitch is quick business. Too short is a pain and usually requires re-tying the knot. Also, this of course assumes the pitches aren't maxing the length of your rope. One of these anchors requires about a minimum of 10-15 spare feet for the knots.
Other disadvantage: Technically, doesn't equalize as well as other options *in theory*. I suspect that the stretch of the rope helps more in this regard than is immediately apparent AND, furthermore, on truly bomber bolts in good rock equalization really doesn't mean much. Either bolt by itself is still about twice what you need, and with the redudancy on hand...
Edit: In an attempt to pre-empt some of the less perceptive redundancy babies, no, this does not offer a redudant anchor for either climber, technically, as if the rope is cut that's the ball game. However, I fail to see how that situation is different during the climbing itself, so I pretty much consider the point moot. If you trust the rope enough to take a lead fall on it, you can damn sure trust it as the anchor.
2) Anything else, such as a single leader leading multiple pitches, questionable bolts, or bolts of offset placement (much like the picture in the OPs post), and it's hard to beat an equallette with an 8 on a bight on each arm at the appropriate length. Good equalization, limited extension, high utility are all easily yours. Additionally, one can leave it pre-tied for the duration of the climb if the belays are known to be bolted and slap it on to the anchors in a matter of seconds upon reaching the belay.
I prefer the three-strand variation of the equallette myself. Your mileage may vary.
If this helps anyone...
(This post was edited by ja1484 on Nov 3, 2007, 10:38 PM)
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mr_belay
Nov 4, 2007, 3:03 AM
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i like this set up. quick clean and fast. using the rope if enough is available is even faster option but on long grade III or IV climbs in the wilderness this type of set up is the order of the day. if i came up on the station and found that set up by my leader i would count my self lucky and think about adding some extra pitches to my day :) on a side note id suggest some lighter gear over a beer, later on though.
(This post was edited by mr_belay on Nov 4, 2007, 4:33 AM)
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walkonyourhands
Nov 4, 2007, 9:50 PM
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Doubling the clove should indeed be a good idea, by clipping a twisted loop to the 'biner after doing the clove you could even get the whole sling into the system again without having to worry about the tail slipping through.
Clipping bolts directly with your rope is of course the quickest, cleanest setup, especially with doubles/twins.
But the fact that keeps me from doing so ist that I usually belay the leader from the anchors with a munter for several reasons. (bolted belay)
Here, the discussed setup offers the advantage, that in case of a fall, the belay biner can only move within the 'eye' and not getting out of reach or lifting the belayer with the whole system.
Anyways, as I mentioned above, I completely trust the sliding x and other well-used systems on bolted belays, let's stay on the hypothetic level.
rgold, as soon as I can get my hands on the whole study (right now I only have the rumor that it comes out this month), I'll let you know about it here.
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gobennyjo
Nov 4, 2007, 11:44 PM
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reg wrote: sweetchuck wrote: ... the sliding x needs two strands to be cut to fail. sc how u figure that? the SX protects you if one legs gear or bolt fails - cut any part of the sling and ur gone
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altelis
Nov 5, 2007, 12:57 AM
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walkonyourhands wrote: Clipping bolts directly with your rope is of course the quickest, cleanest setup, especially with doubles/twins. But the fact that keeps me from doing so ist that I usually belay the leader from the anchors with a munter for several reasons....[/quote "walkonyourhands"] as a quick aside----if you are using singles, doubles, whatever, the fast way to go if you are swinging leads on a bolted belay: 1) figure out how long you need your 'attachment" to the anchor to be. at that distance from your harness tie a double loop figure eight but don't cinch it tight 2) clip each bight to a bolt and then cinch it down so that it is equalized 3) in the free end of the rope coming out of the anchor/knot tie butterfly knot. 4)clip a biner into the knot, tie your munter, attach the guide/reverso/b52/what-have-you voila, fast, simple, uses the rope and you have a master point
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fulton
Nov 5, 2007, 1:15 AM
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walkonyourhands wrote: What's your opinion on that? Cheers for your comments!
You are a RETARD.
We're all stupider for having looked at this.
You deserve to die - and you will - using bullshit like that.
To this guy's partner: Find someone else to climb with - unless this is a suicide pact.
Cheers.
_____________
no part of this post is a joke, I really do think you are stupid
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ja1484
Nov 5, 2007, 1:19 AM
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fulton wrote: walkonyourhands wrote: [image]http://bergsteigen.at/pic/Forum/backup/8802d333-cd37-4ec2-8ba2-29fe1fc0753a.jpg[/image] What's your opinion on that? Cheers for your comments! You are a RETARD. We're all stupider for having looked at this. You deserve to die - and you will - using bullshit like that. To this guy's partner: Find someone else to climb with - unless this is a suicide pact. Cheers. _____________ no part of this post is a joke, I really do think you are stupid
Come again? As anchors go, what's pictured above is fine. You could probably come up with (as many of us have suggested in this thread) faster/cleaner methods of rigging, but there's nothing inherently wrong with what the OP posted.
I would love for you to expound on your little diatribe there as to what's so wrong with that anchor.
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stagg54
Nov 5, 2007, 3:07 AM
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sweetchuck wrote: the sliding x needs two strands to be cut to fail.
WHAT??
to the op: You Euroes sure are weird. I see no reason to rig a belay this way.
Here is a much easier method.
Take a double length sling.
Clip it to both bolts
Pull down middle
tie overhand.
Easy and simple. I know someone is going to say it is not equalized but I disagree. 9/10s of the time You're going to have a piece directly below you a few feet. When you tie the knot equalize it so that it pulls in that direction. Problem solved.
Works 95% of the time.
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LostinMaine
Nov 5, 2007, 2:14 PM
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Some good comments so far. I'm curious why the locker is clipped through the rap ring on the left bolt, though. I can't see what kind of ring it is clearly, but to have the MP attached to an aluminum ring seems unwise (although it does look like a nice beefy ring on this particular anchor).
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