Mountain Project Logo

Self-equalizing vs. static anchor

Wiled Horse · · Unknown Hometown · Joined Dec 2002 · Points: 3,669
John Long wrote:Quad -JL
whats a Quad?

my 2 sense: Use bomber gear for belay anchors. If there is not bomber gear options, belay somewhere else. I also like to use the rope to anchor off.
mattm · · TX · Joined Jun 2006 · Points: 1,885
Darren Mabe wrote: whats a Quad? my 2 sense: Use bomber gear for belay anchors. If there is not bomber gear options, belay somewhere else. I also like to use the rope to anchor off.
Quad = Google Books Link
berl · · Seattle · Joined Apr 2008 · Points: 25

srene sar-har nerds kiss srele quad acr slidingx. or was that p90x?

Buff Johnson · · Unknown Hometown · Joined Dec 2005 · Points: 1,145
mattm wrote: I'd also be interested in reading about these tests. In my experience, Rescue anchors are only vaguely similar to climbing ones. In SAR-HAR, EVERYTHING is MUCH MUCH stronger, over engineered and redundant. If these tests were with RESCUE anchor systems I'm not at all surprised they held. What you want tested are the FUNKY anchors climbers run into and are forced to use since it's the only option. Weird Rock, small nuts, placements in non-ideal directions etc etc.
This is actually not entirely true. The two things I see different are the need to use less elastic mainlines and larger mass. While the difference in mainlines between what climbers use to soft-catch and what you need to manage an evac is important to take note of, it still gives you a worsened case than what a dynamic rope would do at the anchor. The rocks, ice, mountains, trees, physics, gravity, etc. They are all still the same and trad gear is still trad gear. Although, arguing a crappy set of dogshit placements is worthy of testing as a viable anchor doesn't really tell us anything other than we have a crappy anchor which we already know going into the test.

Increases in the safety factor by doubling up materials and trying to build in added redundancy does not necessarily make the situation more safe nor more operationally effective. It is only perceived that everything needs more, because more is better, right?

To some extent, speed is still safety in a varied environment.

Rich, off the top of my head look at JoshSAR at the ITRS online, though you still would want a larger sample set and you won't see the videos on how they setup anchors which was all pretty much straight forward using climber's mentality of rocks' natural features and keeping things quite simple. They even tried placing bad pro with the good pro.
Kyle Heise · · Unknown Hometown · Joined May 2015 · Points: 0

I have been lurking on mp for a while and I finally decided that I would post. I may be a little late for posting to this thread, but maybe it will add to the discussion.

There are many different acronyms for anchor builind (e.g., SRENE, IDEAL, EARNEST). It should be stated that equalization is important; however, it is not as important as solidity and redundancy. Nonetheless, we still ought to strive for equalization so that we do not place un-needed stress on our anchors. In theory, there are two types of equalization: static equalization and dynamic (self) equalization. I, currently, know the following anchor methods that have been widely accepted , of which only one is hardly used in current practice. These methods all vary in practical use and can look different, but I consider these to be the primary or base methods that are built upon.

#1: Old-school rope tie in (There is no equalization)--You clove hitch/ figure 8 a rope from one anchor point to a second and/or third then the live rope feeds down. It is used for rappelling.

#2: Simple Static Equalization-- A 2-3 point anchor system made with 2-3 separate slings, runners, etc. This supports a specific direction of pull. If the direction is changes it is no longer equalized.

#3: The Cordlette (Static Equalization)-- A 3 point anchor system with a single cord tied with a master knot. There is is a little more extension, but in essence it is the same thing as #2, just as redundant. However, there is more extension (a little extension is a good thing but too much is bad) and it is far simpler and easier to equalize.

#4: The Sliding-X (Dynamic)--This 2 (or 3) point anchor system. form of equalization allows the the system to self-adjust to the direction of pull. People have claimed that this form distributes the weight equally among anchors, but it does not. If the direction of pull is too far off to one side the amount of strain on a particular anchor is great. This is because it changes the angles between the anchor points. A variation to minimize the extension uses 2 limiter knots (usually an overhand) instead of the "magic x". The sliding x is not redundant. The limiter knots are. The equalization in this method is actually really great, but if an anchor fails, there will be a sudden shock for put on the other anchor(s). Although the limiter knots variation reduces this, it is still a concern.

#5. The Equallete (hybrid mixture between static and dynamic) -- A 3-4 point anchor system which typically uses 20ft of 7mm perlon cord. This method tries to overcome the extension/friction elongation of the sliding-x and the poor equalization of the cordlette. This method seems complicated, but with some practice it makes sense and is actually pretty easy (or it was for me). The tie in point has limited knots to the sides. The ope extending to the anchors on either side for two loops (one per side. The can use a figure 8 on a bight (usually if one side has one anchor point) or the rope can be attached with combinations of clove hitches, sliding-x's, etc. The tie in point has two loops just like the variation on #4. You can use one carabiner (if so, put a half twist in one of the strands), or two carabiners (one on each strand). This system takes a little more time to set up, but addresses some of the critical issues with the other methods.

--addendum-- I have read (but never tried) if you use a master knot of some sort (such as an overhand, figure 8 on a bight, bowline on a bight. double alpine butterfly, etc) you can place a piece of pro that pulls in the opposite direction of the anchors and attach it to the safest part of the knot. You wouldn't make the connection taught, because that would put stress on the anchors. The purpose would be to keep the direction of pull in the place you had intended. Any thoughts?

Now, which should you use? The answer really depends on what sort of climbing you are going to be doing. I think there is a time and place for both static and self equalizing anchors. Every climber should know how to create them. I would say that if you are a top-roper, you may not need to worry as much because there are hardly and serious falls. At least not like those seen for sport and trad.

If I said something that was wrong, please correct me. Anchors are life and death. If I was unclear, ask and I'll rephrase it.

Sources:
Mountaineering: The Freedom of the Hills, 8th Ed.(The Mountaineers Books, 2013)
The Outdoor Knots Book by Clyde Soles (The Mountaineers Books, 2008)
The Complete Guide to Rope Techniques by Nigel Shepherd (Falcon Guide, 2007)
Anchors in Earnest by Cyril Shokoples (RescueDynamics.ca, 2008)
Climbing Anchors, 2nd Ed. by John Long (Falcon Guide, 2006)

patto · · Unknown Hometown · Joined Jul 2012 · Points: 25
Kyle Heise wrote:I have been lurking on mp for a while and I finally decided that I would post. I may be a little late for posting to this thread, but maybe it will add to the discussion.
This discussion will continue for decades more...

Out of all those thing you listed you neglected listing the strongest, minimalist, and most versatile approach. Using your climbing rope for an equalised anchor.
eli poss · · Durango, CO · Joined May 2014 · Points: 525

1 use the rope if swinging leads
2 with good placements, speed and simplicity are much more important than getting perfect load distribution. i'd try to equalize 2 strong, multi-directional pieces and back it up by 1 or 2 more if it saves me 5 min setting up and breaking down
3 if you really wanna get good load distribution go with an equallete. it's the best balance between load distribution (ACR, AE, sliding X) and redundancy and limiting extension (cordallete) and doesn't take too long to set up with some practice. if using a cordallete, using cloves on ends instead of a tied loop will help mitigate stretching due to the lack of a knot. if i know i have bolted anchors, a pre-built quad is extremely fast to set up and about as bomber as it gets. it's just 2 clips and a clove on a locker thats already there and then you're off belay
4 you will be much faster when it matters if you practice setting up and breaking down anchors at home, for example on a rainy day when you can't climb.

Malcolm Daly · · Hailey, ID · Joined Jan 2001 · Points: 380

All this is moot if all your anchors are bomber and it is multi-directional.

John mac · · Boulder, CO · Joined Oct 2008 · Points: 105

I just clicked on this an laughed when I realized I was the one who opened up this can of worms 4 years ago!

cdec · · SLC, UT · Joined Jan 2007 · Points: 654

Funny you should ask. Folks seem to only talk about a piece blowing. Well I was involved in an accident earlier this year that resulted in one leg of our pre-equalized, two bolt anchor being chopped. If I had Magic-X'd I would be dead, no question. Doesn't happen often but it happened at least once.

Here's a link to the thread here on MP.
mountainproject.com/v/rock-…

Unless there is a large change in direction between the last point of protection and the anchor I can think of few reasons to go self equalizing.

Redundancy saved my life.

june m · · elmore, vt · Joined Jun 2011 · Points: 110

The one down side of equalizing with your rope is if you have to self rescue you have to escape the system first. I personally like an ovbious power point for my second to clip into.

john strand · · southern colo · Joined May 2008 · Points: 1,640

I'll bite..escaping the anchor is the stupidist god damn thing ever..what will you do / downclimb..rappel with no rope ?? WHAT

You never ,, ever can really equalize an anchor..not really.

Build your anchor the best you can, use your ROPE to tie in end of story.

csproul · · Pittsboro...sort of, NC · Joined Dec 2009 · Points: 330
john strand wrote:I'll bite..escaping the anchor is the stupidist god damn thing ever..what will you do / downclimb..rappel with no rope ?? WHAT You never ,, ever can really equalize an anchor..not really. Build your anchor the best you can, use your ROPE to tie in end of story.
No, but you can ascend/descend the rope, anchor your injured partner, and take the rope to rap off; or rap down with your injured partner. Both of these options require you to escape the belay. Of course, this can be done even with a rope anchor, it just has to be done differently than with an independent anchor. How I anchor in, either with the rope or with a cord, is not decided by the extremely remote possibility that I may have to escape the belay.
Kyle Heise · · Unknown Hometown · Joined May 2015 · Points: 0
patto wrote: Out of all those thing you listed you neglected listing the strongest, minimalist, and most versatile approach. Using your climbing rope for an equalised anchor.
Thank you patto! I spend most of my time on tr, mainly because I lead trips for grade school-aged kids. Also, being a Wisconsin based climber I have not had the opportunity to multipitch. I have read about that anchor at one point, but it slipped my mind. I would say that it is a great option, being minimalist and versatile; however, I my gut tells me to contend with "strongest". Before I can do that though I'll have to try it and read up on it a bit.

Does anyone have any thoughts about the addendum part, with the opposing anchor to maintain the direction of pull centered? Is it even worth it really?

ps- I was a bit surprised that anyone would comment after me. So this is great!
RangerJ · · Denver, CO · Joined Jan 2012 · Points: 65
Kyle Heise · · Unknown Hometown · Joined May 2015 · Points: 0
JBennett wrote:http://blackdiamondequipment.com/en/experience-story?cid=qc-lab-sling-strength-in-3-different-anchor-configurations
I think to some extent this is a fair point. However, Clyde Soles makes the point, "Lab tests don't tell the full story of how well a rope works in the field. Some ropes are designed to do little more than look good on tests. They are safe when used properly but may handle poorly and wear out quickly" (The Outdoor Knots Book, 35). Consider the difference between Perlon, Spectra, Spectra-A, and Black Diamond's Gemini.

Strength Comparison of Prospective Cordelette Materials*

1. Tensile Strength (Single Strand)

12 kN-7 mm Perlon (Sterling)
17 kN-5.5 mm Spectra (Blue Water Titan)
18 kN-5.5 mm Spectra A (Maxim)
22 kN-5 mm Gemini (Black Diamond)aka: Tech Cord(Maxim)

2.Loss in Strength When Knotted with a Figure Eight

8%-7 mm Perlon
47%-5.5 mm Spectra
39%-5.5 mm Spectra A
60%-5 mm Gemini

3.Cordelette Strength (One Anchor)

22 kN-7 mm Perlon
17 kN-5.5 mm Spectra
23 kN-5.5 mm Spectra A
18 kN-5 mm Gemini

4. Loss in Strength After 200 Flexing/Bending Cycles

0%-7 mm Perlon
6%-5.5 mm Spectra
40%-5.5 mm Spectra A
45%-5 mm Gemini

5. Cordelette Strength after 200 Flexing/Bending Cycles

22 kN-7 mm Perlon
16 kN-5.5 mm Spectra
14 kN-5.5 mm Spectra A
10 kN-5 mm Gemini

  • Data taken from “Comparative Testing of High Strength Cord,” presented by Tom Moyer and Chris Harmston at the International Technical Rescue Symposium in October 2000. Recorded in "Choosing Material for Your Cordelette" by the Seattle Mountaineers Climbing Committee, 2001; which also says, "It is interesting that once you consider the loss in strength due to flexing, the materials with the highest tensile strength make the weakest cordelettes".

The 48" runner they used, was likely made of HMPE (i.e., Spectra to Americans or Dyneema to Europeans). This material looses strength when knotted, when Perlon (which is basicaly nylon for all intents and purposes) does not. They claim, "[K]nots reduce the ultimate strength by anywhere from 40-60% and the failure mode is always at the knot". If your point was to say, go with the sliding-x, I think the lab test evidence says yes and no at the same time. It is true that knots weaken ropes/cords/webbing because it "pinches" the the material. The knot type is also important. The overhand knot reduces strength to 58-68%. Whereas the figure-9 is at 68-84%. My point is this: Strength is never the real issue. The Black Diamond link preformed a test only comparing the measurements of strength using all of the same material and had everything controlled. That is how you conduct a test. However, there are other variables to consider. The link states, " I'm not going to get into the merits or negatives of each situation (e.g., shock loading if one anchor placement blows, how "equalized" they actually are, etc)". Their test means very little.

I do not thing that the strength of gear even comes into question (unless you do not inspect it and then it fails). The larger concern is pro placement and how it is affected by the system you use. If a system is not equalized well, you run the potential risk of loading an anchor point too much. If you placed pro poorly and it is loaded more than the others the probability of failure is greater.
eli poss · · Durango, CO · Joined May 2014 · Points: 525
Malcolm Daly wrote:All this is moot if all your anchors are bomber and it is multi-directional.
As much as i hate to disagree with someone with much more experience than myself, i think that making such a broad statement is dangerous. i would guess that most climbers, other than the most experienced ones, cannot determine exactly how strong their pieces are as they are very rarely significantly tested. i think most of us can tell a shitty placement from a good one but in many cases the line between good and totally bomber is quite blurry. additionally, i remember reading a statement from metolius that said, basically, 1 in 20 seemingly "bomber" cam placements (considering the placements were judged by doug phillips, i trust that they were actually bomber) failed.
on the other hand, given that a high factor fall is quite rare and that dynamic ropes limit the impact force, speed and efficiency is more important that amazing load distribution. you shouldn't spend more than 3 min building a 3 or 4 piece anchor (not including the time to get good placements).

since i am much less experienced than most of y'all, here's a quote from rgold on the taco.
rgold wrote:He may have consciously or unconsciously settled on 1/20, as it is the threshold probability for deciding on statistical significance. No matter what, I think the message is that our ability to judge well-placed cams is nowhere near perfect, and that failures, although surely unwelcome, are also intrinsic to the very complicated processes that make a cam hold. Small differences in the friction properties of the crack interior, small differences in the solidity of the crack interior, small differences in the "impurities" of the crack interior (water, grass, mud), and small differences in the configuration of the crack interior can all potentially have a large effect on cam performance. The fact that a cam may move, sometimes considerably during a fall, means that the original placement may not be the one that is operative. Really the only response to most of these uncertainties is to make sure the cam lobes are compressed enough that they will be able to tolerate an unexpected change in crack dimensions. There's nothing to be done about unanticipted frictional anomalies.
coldfinger · · Unknown Hometown · Joined Oct 2010 · Points: 55

J Mac.....

The sliding X is no longer an accepted practice, lots of risk and little reward.

Since you should always have a piece in ASAP to protect the belay (or a bomber bolt if it's multi pitch sport) your belay will be predictably loaded anyway.

coldfinger · · Unknown Hometown · Joined Oct 2010 · Points: 55

And as for all these citations of single strand 6mm strengths......

IF you use multiple strands and a good knot, the cordelette strength with be 150% with one loop (because it's a loop and with the knot included) and much more if you use two.

mountaineeringlife.com/wp-c…

wivanoff · · Northeast, USA · Joined Mar 2012 · Points: 674

You guys realize you're posting to a 4 year old thread? Some thinking about what is and what is not acceptable may have changed since the first post.

Anyway, this might be of interest:
reddit.com/r/tradclimbing/c…

Guideline #1: Don't be a jerk.

General Climbing
Post a Reply to "Self-equalizing vs. static anchor"

Log In to Reply

Join the Community

Create your FREE account today!
Already have an account? Login to close this notice.

Get Started.