Equalizing anchors.

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climbingjones

Trad climber

grass valley,ca

Topic Author's Reply - Jan 13, 2007 - 10:10pm PT

Yeah. I thought. How to place the biner. Sliding or tied off knot? That was my question. I guess I did not simplify it enough. Sorry for the confusion. Just trying to get some climbing related talk going here. No confusion for me. I think the way I outlined is the way. Just trying pick some brains.

Climber 46

Social climber

Ottawa, Ontario

Jan 13, 2007 - 10:18pm PT

I haven't seen Largo's new book yet, but my current practice is to tie a figure 8 so there is no extension of the power point if one of the anchor pieces were to fail. It is possible that the new book will provide updated info....Anyone out there know?

Cheers,

Doug

cintune

climber

Penn's Woods

Jan 13, 2007 - 10:21pm PT

This is one of those potentially endless debates, but either way, screamers are great insurance.

climbingjones

Trad climber

grass valley,ca

Topic Author's Reply - Jan 13, 2007 - 10:21pm PT

It was cool, sorry freezing. The ice is so hard. Rare for this area. Just bouldered some smaller stuff. Some short solos as my partner couldnt make it. Shoe-d around a bit. Scoping for tomorrow. Headed to some FAT formations at Rainbow tomorrow, maybe the tracks near 20 and 80 junction. With the partner this time.

john hansen

climber

Jan 13, 2007 - 10:22pm PT

Any one got a diagram showing a sliding W? I think I know how the tied off figure eight looks.

Ed Hartouni

Trad climber

Livermore, CA

Jan 13, 2007 - 10:28pm PT

boy, this topic was flailed to death on rc.com and then that dead horse was beaten repeatedly...

...John Long's latest edition of the Anchors book has some new data from anchor equalization schemes that everyone should read.

Beer 46

climber

Mountain Room

Jan 13, 2007 - 10:58pm PT

"Equalization"

The bad news is: It's impossible.

The good news is: It's unnecessary (nearly always).

climbingjones

Trad climber

grass valley,ca

Topic Author's Reply - Jan 13, 2007 - 11:26pm PT

Unnecassary? Are you serious? Then why not just use one piece at an anchor? Perfect equalization might be unatainable, but some form of an attempt should be made. Otherwise you are using just one piece, no matter how many you have placed. Please explain.

Tom

Big Wall climber

San Luis Obispo CA

Jan 13, 2007 - 11:42pm PT

The sliding W allows the power point to move down before equalizing the remaining anchors if one fails. This means that a pseudo shock-load hits the remaining anchors.

The figure-8 does load the anchors unevenly, depending on the direction of the load and how much care is taken in tying it. However, if one anchor fails, the others are not as severely loaded during the transition from three to two points.

I only climb walls, which means heavy haul bags. I would never use a sliding W for a wall anchor. Having a haul bag break loose and suddenly fall half a meter onto a few meters of perlon cordelette is not my idea of safe climbing.

A sliding W for equalizing a single aid placement (two or three bad pins, all tied together) is not a bad idea, because the load is shared among the bad pieces. The idea here is that none of the pieces is strong enough, so the concept of statistical strength is used to move up past the bad section. If one of them rips, well, that's why they call it A4/A3 loose.

If your belay pieces are so bad that you need to equalize them with a sliding W, you are on A6, which is beyond the scope of rational climbing, and this forum is not the place to find out how to stay alive.

climbingjones

Trad climber

grass valley,ca

Topic Author's Reply - Jan 13, 2007 - 11:47pm PT

No Tom, I dont use the sliding "W" for aid anchors. Free anchors only. When loaded I have witnessed the sliding "W" move and while doing so I can see that the load is being distibuted evenly. I think there is usefullness to both methods. Different situations require different applications.

WBraun

climber

Jan 13, 2007 - 11:49pm PT

Always equalize, be redundant, make your anchors 10 to one safety factor, visualize your power points, good job, and now have fun.

the Fet

Knackered climber

A bivy sack in the secret campground

Jan 13, 2007 - 11:53pm PT

The sliding W is the most effective thing to equalize 3 pieces, you can back it up with another longer cord or sling tied with an 8 or overhand so it doesn't extend much if one piece blows. On that A6 pitch.

I haven't had the chance to get Largo's new book, but in the rc.com thread he mentions the sling/cord tied with an 8 doesn't equalize, most force is on the shortest arm.

I've been using a sliding X with limiter knots (good equalization, little extension) on the two best or closest pieces. And a seperate sling to a third piece, slightly loose, if I think I need it.

climbingjones

Trad climber

grass valley,ca

Topic Author's Reply - Jan 13, 2007 - 11:57pm PT

That is the way that I do it Fet. Seems bomber. Total confidence I feel. The figure 8 does load unevenly, no matter how well you anticipate to load direction.

the Fet

Knackered climber

A bivy sack in the secret campground

Jan 14, 2007 - 12:13am PT

I've been using this trick to shorten the sling for the third piece. I leave my sliding X with limiter knots pretied, so I usually don't have to tie any knots at the anchor. Very fast.

I don't use it like the picture. The way I use it, the quickdraw in the picture is replaced with a sliding X with limiter knots.

rgold

Trad climber

Poughkeepsie, NY

Jan 14, 2007 - 12:22am PT

Here's a summary of the equalization discussion.

There is a sort of Heisenberg Uncertainty Principle for equalization: It is impossible to obtain equalization with no-extension under anchor point failure. The only way to genuinely equalize the load to multiple anchors is to have some sort of pulley system. But if an arm of a pulley system fails, there will be extension.

Until recently, most climbers used fixed-arm set-ups that cannot equalize in theory and do not equalize in practice. Such anchors are distributed anchors, not equalized anchors, and there is a chance that if loaded to anchor point failure, the load will be applied sequentially to single points rather than divided amongst them.

Pulley systems that allow for large extensions if a single piece fails are undesirable, so the challenge of practical equalization is to produce a pulley component with relatively little rope or webbing in it so that not much extension is possible.

There are three further challenges here.

One is that you don't want to burn up too much gear at belays. Many of the systems proposed on the rc.com extravaganza use five or six biners, not counting the power point attachments, for a three-point anchor. That's ten to twelve biners from your rack devoted to a pair of belay stations, too much unless you're on a big wall and lugging the kit that goes with it.

The second challenge, a much more daunting one, is friction. A pulley system won't equalize if the frictional losses around components are too great.

The third challenge is complexity. A system should be highly adaptable and deploy rapidly with little or no potential for disasterous mistakes.

There is a another challenge, advanced by Largo, that anchoring solutions should be obtained with simple gear like slings and cordelettes. I haven't listed this as one of the challenges to be met because I think the only way to make real progress is to concoct some specialized gear. Although I am deeply sympathetic to any aversion to gadgetry, I also have to admit, looking at all the mechanical doo-hickies hanging from my harness, that we are several decades past anything like true economy of gear.

Largo's equalette meets the challenges for two-point anchors, but is a half-measure for three (or more) point anchors. The sliding W mentioned by climbingjones fails both the friction test and the extension test and so is a poor candidate for a solution in my opinion.

Most climbers are happy with their fixed-arm rigging, but that could change if equalizing solutions for multiple anchors are devised, solutions that meet the three challenges listed above.

Beer 46

climber

Mountain Room

Jan 14, 2007 - 12:23am PT

Do as Werner sez.

Seriously though, Mr. Goldstone has mentioned some of the difficulties in actually achieving "equalization". In the real world, it aint gone to happen.

Some people seem fixated on the idea of equalizing, thinking it's always required. Nonsense. Equalization is actually a relatively new idea (last 30 years or so). The fact is the gear is strong enough (usually) without equalization. In most cases, you want more than one piece to provide backup for the unexpected, not because one isn't strong enough.

Of course, there are exceptions, in which case, load sharing (a far more accurate term) strategies are called for. If you're in such a fix, you should also be thinking about other survival strategies, like "Don't Fall".

Rocky5000

Trad climber

Falls Church, VA

Jan 14, 2007 - 12:38am PT

Clever sling-shortening, though by instinct I get queasy when sling material rubs against itself. Not a factor, though, on this minor scale. Just keep a paranoid eyeball glued to it.

There is no perfect anchor, ever; it's an unlimited opportunity for creativity. If you have two really strong pieces, you can make it simple and quick, if the force vector is fairly definite. If all you have is marginal garbage, you have to pull out all your tricks and go nuts - screamers, cordlettes, sliding W with backups to brass micronuts duct-taped onto a rugosity - whatever. If if if. Although it's fun to browse J. Long's many interesting photos of anchors, I never remember any of that when I'm up there; I have to respond to whatever unique weirdness is thrown at me, and do it right.