Interesting Cordellette Study

[ken4ord]

So anyone know where there is step by step diagram for rigging an equalette, I like to mess around with rigging one this weekend.

 

 

This rig seems pretty cool ACR (alpine cock ring)

 

Hey Ken, lay out your cordalette, start at the center, tie a couple of overhand knots a couple of feet apart, and then tie off your pieces with clove hitches. Seems to take about the same amount of time to rig as a cordalette if you've already got the knots in the middle.

 

Alright now I am seeing it, though I got a few more questions.

 

*First about how far apart are people setting up the knots in the center?

 

*All the pictures I have seen have been 4 point anchors. Setting up a three point would probably be set up the same way though one of the arms you would not have to use clove hitches? I would think that setting a three point anchor would change the load ratio would be 50% on the single piece arm and 25%/25% on the arm with two pieces?

[JayB]

I think you're right about the load distribution.

 

If all three pieces were bomber I'd probably just use another clove for the loop tied to a single piece, but if not I think I'd just tie an overhand or a figure-eight on a bight to adjust the length of the loop and use this arm for the best piece of the three.

 

In super-sketch situations where it'd be worth investing the time in a megacluster, I suppose you could clove one or more of the "arms" to a biner slung on a sliding-X between two pieces...

 

When I was playing around with this rig something around two feet seemed to work most of the time. If you need to belay from a stance that's way to the left or right of the central point of your anchor then you might need more distance between the knots in order to prevent the knot from restricting the equalization.

 

 

[ken4ord]

Hmm, the other question I just remembered was that in the diagrams show the power point with two locker biners, a single locker per strand. Couldn't you just put a twist in one of the strands and similar to what is done in the sliding X?

[Bill_Simpkins]

Everything has its ups and downs.

I usually avaiod a cordellete by using a Self-Equalizing Figure Eight knot with the rope. It's dynamic/self eqaulizing and fast to tie. Just tie a figue eight on a bite then thread the bite back through the top most loop of the figure eight. Bingo, a 2-3 point self equalizing anchor. Not very good for leading in blocks, but good for swapping leads. A cordellette is great for leading in blocks.

 

[plexus]

Wouldn't this have the same drawbacks as the cordellette?

[underworld]

maybe... minus the drawback of carrying a cordellette.

[Otto]

Thanks for the cool and instructive photo, Bill S., makes the technique clear.

This could be used on most pitches, as there is usually some rope left over. Sometimes, however, it's a stretch just getting to the belay...

[David Trippett]

The friction in that modified 8 is so high during a high load as to render it virtually static. The fact that you use dynamic cord to make it is its saving grace, that and that you can adjust the pull direction easily when its not loaded. Another problem is that if the wrong arm fails the whole thing extends. It's a good one to know anyway....I've used it quite a bit.

[catbirdseat]

Everything has its ups and downs.

I usually avaiod a cordellete by using a Self-Equalizing Figure Eight knot with the rope. It's dynamic/self eqaulizing and fast to tie. Just tie a figue eight on a bite then thread the bite back through the top most loop of the figure eight. Bingo, a 2-3 point self equalizing anchor. Not very good for leading in blocks, but good for swapping leads. A cordellette is great for leading in blocks.

 

Realize that with this knot that if a piece fails, you CAN get extension, depending on which piece fails. My guess is that it would be mitigated by a lot of friction as the rope pulls through the knot.

 

Second point is that since the rope is part of the anchor, it is more difficult to handle emergency situations.

[paulraphael]

This rig seems pretty cool ACR (alpine cock ring)

 

If anyone's interested, the info on the ACR has been updated. We've been field testing it all over the Gunks and Will Gadd is going to start testing it in the Rockies. Jim Ewing at Sterling has done some preliminary pull tests and given it the thumbs up.

 

My partner and I find it faster and more versatile than anything else we've tried and are planning to stick with it unless something better comes along.

[catbirdseat]

Thanks for contributing. I can't wait to try it out. Have you considered using a butterfly knot for shortening an arm? Depending on your method of tying it might be harder to do with two strands than a simple overhand.

[JosephH]

I suspect many of the rigs from the original sliding-x thread would perform as well.

We explored any number of similar equalizing alpine rig variants such as the ACR. Here is one

of many that was looked at:

 

 

This one linked in the ACR post is on the simpler side of the various ones explored.

It's pretty much a standard alpine equalization rig with different ways of tying an

extension-limiting knot on one leg which can be put to other uses. In general I don't

find there to be anything particularly compelling about this design over a lot of the

other apline equalization variants.

 

In the end I still prefer the Equalette, Quad, and Michabich's modded equalette (below)

over this 'ACR' design which still suffers badly on the extension front.

 

[paulraphael]

Thanks for contributing. I can't wait to try it out. Have you considered using a butterfly knot for shortening an arm? Depending on your method of tying it might be harder to do with two strands than a simple overhand.

 

Yeah, we tried the butterfly, but it was too hard to tie in a double strand. The whole idea was an anchor that was fast and simple in the field, not just on paper.

 

The fat adjusting knot was our biggest concern until Jim Ewing tested it. He found it to be more than strong enough, even when tied sloppily (which we always do) in either 7mm nylon or technora.

[paulraphael]

I ... this 'ACR' design which still suffers badly on the extension front.

 

In most cases it's easy to limit extension to 6 inches or less.

 

How much extension you're willing to tolerate is a whole other conversation, but the biggest concern is making sure the belayer doesn't get yanked off the ledge. I tend to be more worried about extension if the pro is sketchy, if it's a hanging belay, or if it's a precarious ledge. Other times it's pretty much a non-issue, and speed and simplicity are more important to me.

[Bill_Simpkins]

This is nice too.

[mattp]

I find all of this very interesting, and I can think of a couple of occasions in the last few years where I might have wanted to use one of these more complex equalized anchors but I wonder just how often all of this complexity is warranted.

 

Whether in the mountains or at the crags, 99% of the time I simply tie in to the closest and or most secure anchor to where I want to sit or stand, and make sure I have one or two "back up" anchors attached by whatever is the most convenient combination of slings or the main belay rope.

 

I appreciate the information, and next time I want to take some time out of a climbing day to "play with anchors" I will try some of this stuff, but failing belay anchors seem to me to be one of the least important things to worry about and way down the list beyond inadequate pro, edges that have the potential to cut the rope, or just plain rope management. Am I missing something?

[paulraphael]

This is nice too.

 

I used a web-o-lette for years. it's basically a cordelette (with all the associated stengths and shortcomings), with the advantage of compactness, and the disadvantage of being made out of extremely static webbing, which Long and Ewing found to increase forces and decrease load distribution. In general I'm more comfortable with 7mm nylon, based on tests I've seen.

[paulraphael]

... failing belay anchors seem to me to be one of the least important things to worry about and way down the list beyond inadequate pro, edges that have the potential to cut the rope, or just plain rope management. Am I missing something?

 

I agree with that. The odds of anchor failure are really low (mostly because anchors are almost never tested ... people seem to know better than to fall directly on them).

 

The issue is that the stakes are so high. When anchors do fail, it's usually the end for everyone involved. And since there have been a few high profile (and fatal) anchor failures in recent years, and since recent studies show that most of the common techniques leave something to be desired, the subject is worth a second thought.

 

But I would never switch to something slow and complex that introduces whole new dangers just because it works well on paper or in the lab. I'm only interested in solutions that are fast and versatile, and difficult to screw up.

[catbirdseat]

Here are the things I like about ACR:

 

1) It is as fast as the old way I've been using which is tying off in a knot.

2) It equalizes much better.

3) It makes more cord available when anchors are widely spaced.

4) One can better adjust the location of the power point, just by adjusting the length of the loop on the overhand knot.

5) Extension is really minimal. Usually what you have in an anchor is two short arms and one long one. By putting the overhand on the long leg, you've got a limiter knot right where you want it.

6) It doesn't have permanent limiter knots in it like the Equalette that I'd have to untie to use the cord in other applications like the Quad, or lassoing a boulder.

 

Commenting on the setup that Joseph showed: It is as easy to tie as the ACR, but its disadvantage is that you can't tie a limiter knot in any of the legs. These setups can have one and only one limiter knot, or they won't slide. The fixed power point in Joe's setup is equivalent to a limiter knot.

Edited June 23, 2007 by catbirdseat

[paulraphael]

you can't tie a limiter knot in any of the legs. These setups can have one and only one limiter knot, or they won't slide. The fixed power point in Joe's setup is equivalent to a limiter knot.

 

Same is true for Trango's Alpine Equalizer (which uses the same basic design). You have to chose between dynamic equalization and limited extension, but you can't have both.

[catbirdseat]

If you use the shorter Alpine Equalizer and slings to extend the legs to the pro, you don't have as much extension, but then of course you've made everything more complicated by having to use slings.

[paulraphael]

If you use the shorter Alpine Equalizer and slings to extend the legs to the pro, you don't have as much extension, but then of course you've made everything more complicated by having to use slings.

 

Right. And then there's the versatility issue, like what if you need to tie off 4 pieces, or if you want to sling a big block or tree or icicle.