ACR Anchor Method?

Peter Springs wrote: Is there a reason that it wouldnt be better to tie an Alpine Butterfly? If there isnt, why not tie a knot that doesnt have that possibility? It's not like the Butterfly is hard to tie...

YMMV, but I'm a lot quicker with a figure 8 or overhand.

paulraphael wrote: The pull tests done on the extension limiting knots didn't show this to be an issue, either with 7mm nylon or 6mm technora. Jim Ewing at Sterling said that the weakest of the knots, tied sloppily, held 12KN without trouble. In other words, in a worst case scenario the knotted arm could hold a factor 2 fall all by itself. The knot would be very low on your list of things to worry about.

Paul, thanks for the reply to this thread. I've only posted in the first place to look at the extension issue that some folks had issues with. In my photo, I just wanted folks who hadn't tried this method to see how limiting extension could be done, and what the distances looked like in a real world placing, with real world angles. The placement that I "blew" wasn't really a bad placement at all, it just served for a before-and-after photo. Some people like to get bogged down in minutia.

Thanks to you and Peter for discussing the knot issue and adding something useful to the thread. I've used an alpine butterfly for tying in on a 3 person rope team, but never really weighted it in a fall...with 5mm cord, is one going to be easier to untie? maybe that'd be the tie breaker.

And of course, many thanks to you for introducing a well rounded anchoring method that meets my needs, is versatile when not used in this form, and is pretty cost effective, thus leading its components to be replaced more often (by the average dirt bag climber, anyway...)than say a $35 dollar quasi-equivalent. My partner and I are both climbing on A.C.R.s now.

My concern for bringing up the knot thing is that capsizing knots is a real issue; knots that are pulled in incorrect directions can come undone. I just think that people should be aware of that instead of simply following a diagrammed out thing that they say on the internet that someone told them was pull-tested, and likely it wouldnt fail.

At least all the cards are on the table now (as far as the knot goes) and people can chose for themselves.

As far as which knot would be easier to unload, I'm not sure, you'd have to try them both to know for sure, I think.

For your reading pleasure:
xmission.com/~tmoyer/testin… (these tests are on 11mm dynamic line... imagine what they could be on 5 or 6mm)

Well this is a slice of fried gold! It seems like It could save a lot of time.

What do you guys think about using this stainless steel rap ring for my ACR? Those light weight aluminum ones just dont make me feel warm and fuzzy on the inside.

In case anyone is interested. Best 3 point anchoring method I know of if your so inclined.
rockclimbing.com/cgi-bin/fo…;search_string=dorkalette;#2178398

Basically start out like cordelette clove each piece and your done. Has the best properties.

For two points use the quad. Besides when one isn't worried about strength (bolts etc) why would these two not suffice for just about everything?

Thoughts welcome

Couloirman wrote:What do you guys think about using this stainless steel rap ring for my ACR? Those light weight aluminum ones just dont make me feel warm and fuzzy on the inside.

Well, it's ~3 times heavier (90 grams vs. 31 grams)- but if you don't mind hauling around some training weight then go ahead and use it. With the way the force is distributed in this setup, are you really concerned that you could break an aluminum rap ring? I don't think it's possible unless you're doing some serious static line drops.
I normally use a 3-headed figure-8 knot and the rope when swinging leads, but I use this system now instead when I would otherwise use a cordelette and I feel quite warm and fuzzy (both inside and out).

Couloirman wrote:What do you guys think about using this stainless steel rap ring for my ACR? Those light weight aluminum ones just dont make me feel warm and fuzzy on the inside.

If it's those older rap rings that really don't have a rating, yes, I could see your concern. These newer rings with the rating, which really are more than adequate even adding in a reasonable safety factor; I have no problem using as "light weight" and "unsafe" are not synonymous.

I can't believe the misinformation on this forum, how many of you are making stuff up? There are like 6 people talking about "shockloading"... what the hell is that exactly? You can't serously be thinking about what happens after an anchor absorbs most of the energy of a fall, a peice blows, and then some how between this and the extention there's that magical "shockload" that pulls energy out of it's ass and tries to tear the rest of your anchor apart.

The truth is, there's no such thing as shockloading when there's a dynamic rope in the mix, and blowing a peice on your anchors isn't as scary as it seems.

seems to me there are well balanced posts, including some thoughts I wrote back on the first page of this discussion, saying it's an unwarranted fear to begin with in a typical climbing system.

Russell Bangert wrote:I can't believe the misinformation on this forum, how many of you are making stuff up? There are like 6 people talking about "shockloading"... what the hell is that exactly? You can't serously be thinking about what happens after an anchor absorbs most of the energy of a fall, a peice blows, and then some how between this and the extention there's that magical "shockload" that pulls energy out of it's ass and tries to tear the rest of your anchor apart. The truth is, there's no such thing as shockloading when there's a dynamic rope in the mix, and blowing a peice on your anchors isn't as scary as it seems.

You are right that there really isn't any good operating definition of a shock load. You seem to have made up one that legislates all shock loads out of existence. But what people mean when they use this basically undefined term is a load that results from a weight free-falling a certain distance and then being arrested, usually by a dynamic climbing rope. All climbing falls are shock loads, under this definition, the polar opposite of your vacuous term, and any anchor that takes the loading applied by a climbing fall is subjected to a shock load.

One might hope to define shock load in terms of the rapidity of loading. But with a cordelette, blowing a piece means the load will be distributed in some fashion to the remaining pieces, which guarantees that at least one of those pieces will see a very rapid increase in its load. This increase, which occurs just as rapidly as the load imposed by a fall, is not referred to as a shock load by climbers because there was no additional loss of altitude engendering it.

In spite of the fact that, in some sense, shockloading happens in every climbing fall, and in spite of the fact that an anchor is arguably shock-loaded when a piece fails, whether or not there is any extension, when the issue of "shockloading" is mentioned with respect to anchors, it refers to the load resulting from one or more pieces blow and the anchor extending.

When this extension happens, a new or, if you wish, additional fall occurs. In the worst-case scenario, this involves the belayer and the fallen leader. This new or additional fall introduces a new quantity of energy to be absorbed, and so no one's ass is required to pull anything, fall energy included, out of.

The remaining pieces of the anchor are going to have to absorb this new fall energy that is the result of the anchor extension, something they wouldn't have to do with a classical cordelette configuration.

Tests by Jim Ewing have suggested that that extension doesn't matter, which has been translated to mean that shockloading, in the fatally flawed sense used above, does not matter. Unfortunately, these tests were not done in a way that properly mimics what could happen with an anchor, and the negative results observed are a simple theoretical consequence of the configuration used.

This means that we don't know for sure how much or when shock loading in a belay anchor matters. But it is beyond question, frankly, that it could be a very serious consideration, and so the spreading mantra that extension doesn't matter is simply not true.

Forgetting all about the more complicated dynamical model of, essentially, a pair of coupled (damped) harmonic oscillators, and just imagining the leader and belayer falling through whatever distance is dictated by the anchor extension, the classical first-order approximation for peak load says that the peak load will depend on the length of the anchor extension divided by the length of the belay tie-in. This is because, in this oversimplified model, all the energy of the anchor extension is absorbed by the belay tie-in, and the ratio just given is the classical H/L fall factor. It follows that a short tie-in relative to the anchor extension would result in a high "fall factor" and a high load to the remaining pieces, far more than would be predicted for a fixed-leg anchor. In the imprecise common parlance, shock loading could matter a lot.

I might add that using any kind of sling material rather than a dynamic rope as the tie-in to the anchor will exacerbate this problem enormously.

The solution to the issue is, first of all, to limit anchor extension as much as possible if one is using a potentially extending anchor, and then tie in to the anchor with as long a length of the climbing rope as is practical. Under those circumstances, anchor extension involves a small fall-factor, and so the "additional" load to the remaining pieces as a result of extension will be minimized.

I guess I should have just quoted the book.

"While you want to avoid excessive extension in your rigging, a little extension will only lead to the fall being slightly longer, thus increasing the force a little bit."

All references I noticed to "shockloading" were to the forces that come about when an anchor blows in an extendable system. I in no way said that you should ignore extension, just that a failed anchor in a system that would allow it isn't producing the forces most people are imagining.

...and the whole point of my post is that the forces people are "imagining" are possible.

Rgold mentions many factors that could be significant, and one that we can assume is significant: extension that causes the belayer to drop onto the anchor. This would come into play any time the belayer is hanging or partially hanging from the anchor, or any time catching the fall pulls the belayer off his or her stance.

It stands to reason that there are situations when the extension of an anchor could be a prime factor in pulling the belayer off the stance and onto the anchor. This is why I believe that anchors that can extend a lot (more than a foot or two) can introduce fundamentally different problems and forces than ones that just extend a few inches.

When I look for ways to limit the extension of dynamically equallizing anchors, I'm thinking primarily of keeping the belayer from getting yanked off the ledge, and onto the same remaining pieces that are holding the fallen climber.

Well, as usual the DAV have done this one (Panorama 2/2009, also interesting for the dynamic and static tests on various sling materials tied with a clove hitch).

5m drop, 80kg, dynamic rope belayed with HMS on sliding X with 60cm legs. Hanging belayer weight 65kg.

Single leg failure gave 40% higher force than the same test with no extension.

Jim

@ Robb Kranz - You really should consider retying your ACR cordellette so that the tails on your fisherman's knot are longer than a 1/4 inch. A fall onto that could very realistically pull the knot right out.

What ever happened to keeping it simple? Unless you're not swinging leads or need every single damn inch of cord, just use your rope. Why get all in a twist over a 6mm cordalette and its flaws when you have a beefy, dynamic rope at your disposal?

kellycordes.wordpress.com/2…

Simplicity is efficient. Efficiency means speed. Speed means more time to climb.

Most of the materials I've read cover systems utilizing a static cord. I've been using an equalette for about 4 years now. Where should I go to learn the appropriate technique for building an anchor with the rope? I'm curious to know how equalization is achieved...

alpineinstitute.blogspot.co…

Hey Colin. There are many, many ways to tie in with the rope, and you could have a long thread about only that topic. I don't feel like writing that much right now (sorry) but I cut & pasted a hastily written & overall inadequate post I wrote in another thread to get you started. It is geared towards those anchoring with daisy chains, and specifically towards daisy chain users that said using the rope doesn't work when swapping leads, but hopefully it will give a general idea of a few of the methods. HTH.

... I generally prefer tying in with the rope. As I have said before, you are already tied in with the strongest, most dynamic part of the climbing system, so use it.

I will occasionally use Rgold's method, mostly for complex anchor systems, but am not efficient enough with it to adopt it's regular use. Instead I generally use one of the following systems:

For simple anchors (and most anchors are simple) I generally use some version of the double 8 (aka atomic 8, aka bunny eared 8, etc...) and, if necessary, a clove hitch. For example:

-For bolted belays (which are becoming increasingly common, even on old-school MP trad climbs) grab the rope below your tie-in and tie a double 8. Clip one loop to each bolt, then tie your knot of choice (I prefer a butterfly) below the double 8 for a power point to belay off of. This method takes only seconds, as you only tie 2 simple knots with the thing you are already tied in to. Simple, fast, dynamic, easily adjustable (for equalization) and strong. Furthermore, if you desire the option of an adjustable tether & have some extra rope, just leave yourself a long tether by tying your double 8 further down the rope, then clove in wherever you want. When the second arrives, they simply tie a double 8 and clip one loop to each bolt under yours. If needed, tie a second knot to re-direct the lead belay.

-For simple gear anchors (which IMHO is probably 90% of them) the double 8 (or double bowline if you prefer) still often works well. I will generally...
a) in solid rock with at least one super bomber placement, clip each ear of the double 8 to a piece, then below the knot tie a clove to the strongest piece, then tie the power point in between. Give yourself an adjustable tether if you want. The second clips in the same way under the leader.
OR
b) Put 2 pieces together (side-by-side or in series) then another 2 pieces together. Clip each pair with one ear of the double 8, then tie a power point just below with your knot of choice. Leave yourself an adjustable tether if you want. The second clips in the same way under the leader.
OR
c) Tie a triple bowline, clip one loop to each of the 3 pieces, then tie the power point. Leave an adjustable tether if you want, and have the second clip in the samer way under the leader.

As with the first method, all of these methods should take less than 1 minute (not counting placing the pieces, which are the same either way) and are simple, fast, dynamic, easily adjustable (for equalization) and strong.

-For slinging trees/boulders/horns, using the rope is incredibly easy and should already be in the toolbox of trad leaders.

-For more complex anchors, some version of the above methods will often still work. Also this is when a series of cloves (a la Rgold) works well. If I have any slings left over I may incorporate those into the anchor, mostly to extend placements. Sometimes when using small pieces in crappy rock I will use a sling & sliding X to perfectly equalize 2 sketchy pieces before incorporating that leg into the system.

-When using double/twin ropes tying in with the rope is even better. tie the left rope the the left piece(s) with a clove/8/double 8, clip the right rope to the right piece(s), then tie both ropes together into a master point below the knots.

I have used these methods extensively over the years and have come to believe that they are the best way for me. I have used them to lead every pitch, lead in blocks, swap leads, guide clients (where I am definitely leading every pitch) and when following.

I like cordelettes, web-o-lettes, equalettes, & sliding X's, and use them when situations dictate. There is no '1 true path' when it comes to anchor building philosophy, and if always using a cordelette & daisy chain is working for you then by all means stick to it. However making the statement that anchoring with the rope "just doesn't work" seems strange because it works great for me & others I know.

Maybe MP.com should have an Anchor Olympics sometime to get the real truth. I bet Rgold would smoke us all.

Sorry for the long & probably confusing post.
-Mike