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WBraun
climber
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Jan 16, 2007 - 12:37am PT
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Good anchors are really fun to build and present a wonderful challenge to make them solid and robust to the variables that they are encountered.
I love building anchors. I first learned some cool tips from the masters Bridewell and Porter. The Rigging for Rescue course is also an excellent resource although expensive and mostly geared towards rescue situations. That course will open ones eyes toward systems and their dynamics involved towards good solid fundamental anchors.
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WBraun
climber
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Jan 16, 2007 - 12:59am PT
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Hairball back then?
Back then was a blast.
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climbingjones
Trad climber
grass valley,ca
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Topic Author's Reply - Jan 16, 2007 - 02:08am PT
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Werner, I never said that it was hard to figue out. Not for me anyway. Like I said, different situations require different approaches. I was more into hearing how other people did it. I know many ways of building an anchor, making it safe, and equalizing it as best as possible. Not looking to be schooled, I know what I am doing (not dead yet anyway with many anchors built), but I enjoy reading other peoples perspectives. Especially since there are many out there who are smarter than I am with way more experience. You included. I am just enjoying reading about climbing realted topics on this climbing realted website. Go figure.
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Tom
Big Wall climber
San Luis Obispo CA
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Jan 16, 2007 - 02:30am PT
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Largo is right:
"Trying to achieve the same brute strength with passive camming devices presents another magnitude of difficulty hence the modern day need trend toward equalizing." - Largo
His idea that pounded pins are more akin to CalTrans anchors for anchoring whole sections of roadway should not to be lost upon modern alpinists.
In the old days, pounded pins were so bomber, you could belay off one, or two.
But, removing the pins damaged the rock, and the question was: how many more ascents can be done this way?
All things being equal, a clean anchor is not going to be as strong as well-hammered anchor, at least in Yosemite.
A typical belay with a few wedged stoppers, or cams, is not the same as if well-driven pins are used.
Hence, the need to equalize.
But, regardless of the type of anchor, reducing the potential for a shock-load on any of the pieces seems expedient. A sliding W can shock load anchors, but a tied-8, properly tied, will not.
If you're worried about your belay, there is always another way out: climb a few moves up, and then equalize those pieces back down to the belay. How many pieces you need to go up depends on the pitch. I once used six moves above the belay, because the anchor was a loose block.
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ADK
climber
truckee
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Jan 16, 2007 - 02:47am PT
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The only way to prevent shockloading and ensure equalization is to use one piece of gear. Otherwise its situational. ja
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Tom
Big Wall climber
San Luis Obispo CA
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Jan 16, 2007 - 03:58am PT
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"The only way to prevent shockloading and ensure equalization is to use one piece of gear."
I once - once - saw a great idea of one piece of gear at a belay, and I never climbed with that guy again.
I was "shock-loaded" in the brain upon climbing up and and seeing the setup.
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nutjob
Trad climber
San Jose, CA
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Jan 16, 2007 - 04:27am PT
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OK here's a serious question thrown into this mess. Maybe this is what happens over at rc.com (I never wander in that direction).
I studied all the anchor guidance in Freedom of the Hills and the Largo books in the mid-90s. And I was all anal about following the rules when setting up top-ropes and learning on my own with no mentor.
Nowadays on long trad climbs where speed = getting down before dark = not having to bivvy after getting lost... I strongly favor an ultra simple setup. Mostly I set my pieces and clove hitch the climbing rope directly to them in serial (do a sliding X equalization on 2 or 3 pieces if they're crappy). This is really fast and efficient when swinging leads, and requires less gear (e.g. if I forgot a cordalette). Then I belay off of my harness and bear the shock before loading the anchors (hanging belays are different). If need to lead in blocks, tie in with figure 8 on double biners through strong points of harness, then can switch ends of the rope at belays after clipping in to a backup sling on harness.
Aside from the issue of escaping the belay, does anyone have a problem with this setup? I think escaping the belay is not that big of deal if you're in a situation that really requires it (assuming you have some extra slings and biners and you've practiced it), and belaying off harness avoids shock-loading and blowing out crappy anchors.
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Tom
Big Wall climber
San Luis Obispo CA
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Jan 16, 2007 - 04:28am PT
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"I once used six moves above the belay, because the anchor was a loose block. "
Yikes!
Whatup with that?"
Just below the The Shark's Mouth, on Bermuda Dunes.
The teeth were menacing.
Great White Shark, but huge.
Hanging down, sharp, like El Cap now turns into a huge shark there, and those loose sharp flakes are looking like his teeth that are expendible, and if you grab onto them, you fall.
Just above and right of the Slack.
The Shark.
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wootles
climber
Gamma Quadrant
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Jan 16, 2007 - 08:19am PT
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God knows I don't want to get too deep in this topic again but...
There's been a few statements about shock loading and the dangers there of. First we need to define what a shock load is and that's not as easy as it sounds. A simple answer is rapid loading. But how rapid? In normal UIAA drop tests the peak force occurs in roughly 0.11 to 0.17 seconds on the first drop with a new rope. Each successive drop the peak force occurs earlier than the previous. So I would think that shock loading would have to occur sooner than that but then again how high does the force need to be to be considered in the definition of shock load?
I performed tests specifically looking for the theoretical shock loading. I think it's in Largo's book, though I have to confess I have not read it entirely. I feel the tests showed quite conclusively that shock loading from extension is a myth. There are only two dangers I see in regards to extension: potential loss of control of the belay due to redirection and if the belayer is easily startled loss of control of the belayer's bowels. Yes there is a transfer of the force but it does NOT exceed the total sum of the force, obviously. There are far too many variables to calculate what the final force would be but for certain if you are tied to the anchor with a dynamic rope there is no shock loading. That said, I did not test using static lanyards such as daisy chains or Dyneema/Spectra slings. I, and some other people, have conducted other tests that show direct connection with static lanyards is a bad practice. You may be better off with nylon slings but ultimately the rope is your safest option.
So then back to the rapid loading. I'm working from memory here but during the shock loading tests I recall the second peak, the one resulting from the transfer, occurred at a time point roughly equal to twice the time it took to reach the first peak. The first peak occurred earlier than the normal UIAA drop test because of the test method. The method was to use a 'fuse' on one leg of the anchor that would blow before what would have been the normal peak force. For example the first peak would occur at roughly 0.07 seconds and the second, and lower peak, would occur at roughly 0.14 seconds. Those might seem to be super fast but the forces were quite low, under 3kN if I recall. I wish I could find the data. Sterling moved to a new building back in August and the computer that has all that stuff in it somehow got damaged and I haven't tried to retrieve anything from it.
Now for the curve ball... All of this goes out the window in rescue scenarios. When hauling litters extension is potentially a really bad thing. WBraun can probably address this more.
If this horse was the son of God we would be celebrating Easter all year long.
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Largo
Sport climber
Venice, Ca
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Jan 16, 2007 - 11:49am PT
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Gee Willikers, am I really diving back into this . . . again??
Jim wrote: "I performed tests specifically looking for the theoretical shock loading. I think it's in Largo's book, though I have to confess I have not read it entirely. I feel the tests showed quite conclusively that shock loading from extension is a myth."
Maybe a better term is "load multiplication," meaing that somehow in the time that the first piece blows, to the time (fractions of a second) that the second piece starts absorbing the load, said load does not magically increase. In fact, it decreases relative to the amount of energy absorbed by the first piece before it blew out. Meaning if you had initial loading of L3 on the anchor, one piece blows out and absorbs L1, then extends to the second piece, the second piece would be subject to L2 of loading, almost to the pound according to the testing.
The whole thing goes out the window with rescue work because there is no tube/crimp belay device in the equation (through which the load is greatly diminished through rope slippage), no body to fold and give and absorb energy, and most of all, no dynamic rope that stretches upon loading. Here (as is probably the case with big haul bags tethered with static lanyards) it is almost certain that you'd see, not load multiplication, but shock loading, meaning the sudden decelleration of a litter or haul bag could quite possibly bust biners and rip anchors.
JL
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wootles
climber
Gamma Quadrant
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Jan 16, 2007 - 12:07pm PT
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Thanks John. That was a much better explanation than mine. Yeah I forgot to mention the energy absorption of the piece blowing out. I'll keep looking around for the data but I'm pretty sure it's locked up in my computer bone yard. My drop tower and slow pull computers didn't survive the move.
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mingleefu
climber
Champaign, IL --> Denver, CO
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Jan 16, 2007 - 12:54pm PT
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WBraun wrote: "make your anchors 10 to one safety factor"
Are you just being facetious, or is this actual practice in your line of work? How does one go about conceptualizing what a 10:1 safety factor looks like? Or do you just build the anchor ultra-beefy until you have that "feel good" fuzzy inside?
Curious about the concept.
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TradIsGood
Happy and Healthy climber
the Gunks end of the country
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Jan 16, 2007 - 01:07pm PT
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Largo, that explanation of loads and energies is pretty confused.
Meaning if you had initial loading of L3 on the anchor, one piece blows out and absorbs L1, then extends to the second piece, the second piece would be subject to L2 of loading, almost to the pound according to the testing.
Load would certainly be a measurement of force and not energy. The idea that L3 = L1 + L2 is vague as to the definitions of the L's, and likely not right with any reasonable definitions even if you define them to be energy instead of forces.
Measurements are important. One thing that changes after the first piece blows is the elasticity of the rope. It is now "less dynamic", since it will not immediately shrink to its unstretched length.
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Ed Hartouni
Trad climber
Livermore, CA
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Jan 16, 2007 - 10:40pm PT
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god knows I never get this stuff right the first time, but I did do an analysis of the cordolette and the "magic x" equalization of two points and got what I thought was something consistent with the drop tests that wootles did.
My main conclusion from that was basically, don't use stiff slings... nylon slings, as with nylon ropes, have a lower bulk Young's modulus which lowers the force considerably. The difference of lenghts of the arms of the cordolette will cause differnt forces for each of the pieces of protection they are attached to, thus defeating the idea of equalization. However, if you keep this in mind, and if you make sure that the arms are long, rather than short, the differences may be within the margin that your anchors might be able to take.
What you have to be aware of is the cordolette does not equalize.
What I take to be shock loading is simply that the dynamic forces generated have to do with the change of momentum:
F = dP/dt
where P is the momentum... P = m*v and the difference in the momentum is proportional to the velocity that gets stopped, and the time it takes to stop it. This is the same force calculated in the "force factor" equations, so you can get an idea of the dt by first calculating that force, then calculating the change in momentum, and solving the above for dt:
dt = dP/F
When you have a failure of an anchor at some force, some amount of momentum is decreased, which means the falling person has a lower velocity... this sets an upper limit on the force the next anchor will be subject to. This force will be less than the force that would have been generated if the piece that blew wasn't there in the first place.
Anyway, I've had way too much to drink tonight to be at all coherent... another way of thinking about shock loading is to consider how a hammer works. If you push on a nail with the same force you would swing a hammer, you would not press the nail into the wood. But the hammer generates a lot of force because of the the change of momentum over a very short time. F = dP/dt...
That's going to happen in a belay situation. It is possible that practically it is not an issue for blown pieces on a set of closely spaced, closely coupled anchors, but if you had a very long sling connecting the pieces it might be more of an issue.
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GOclimb
Trad climber
Boston, MA
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Jan 17, 2007 - 05:39pm PT
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>> I wrote:
>> There were several excellent solutions proposed on
>> that thread which, while untested by JL's crew, showed
>> slightly more promise than the "accepted" method proposed by
>> JL. Of course, they won't sell any books - which must be why
>> they're considered impertinent. Apparantly the fact that they
>> just might save lives seems not to be as important.
> To which RG responded:
> Perhaps this is what Joe was warning about when he suggested
> not opening this can of worms again. I'm always astonished
> when people pretend to know other people's motives, especially
> when they are ready to ascribe the basest motivations to
> people they don't know for actions they have no basis for
> judging. I hope you find yourself able to apologize for this
> one Gabe, it is way out of line, and contributes nothing but
> rancor to a discussion that might otherwise be useful.
I didn't say he thought the discussion was impertinent, he said that. As for why he would be so dismissive of all ideas but the one presented in the book, I admit - I really can't (and shouldn't presume to) answer that question. But I sure do find the idea of tarring the entire discussion with the dismissive word "impertinent" to be a bit galling. Still, I'll try to remain productive, despite the fact that many find any input (by better minds than mine) so completely valueless.
And by the way, in regards the importance of factoring in the force a falling belayer creates when a piece extends, I could not agree more. As it happens, I introduced that question in the original thread, and (perhaps too) strenuously argued about its importance. I even suggested what I thought was a reasonably simple change to the testing environment to measure this factor. More impertinence on my part, no doubt! ;)
> healyje wrote:
> Wanna share which ones? Preferrably with a pic of each (if you
> can find them). And if you were posting over on the rc thread
> were you doing it under GoClimb there as well (sorry, my
> memory isn't what it used to be...)?
The moniker GOclimb was taken on rc.com, so I'm Cracklover over there.
Here are the ones I'm most taken with for a typical three point anchor. The pros and cons of each are all available in that thread, though I also have my own views on them after using them for a season:
The Mooselette:
The CharlesJMM anchor:
And the two crossed slings:
Werner I ain't, and greater minds and more experienced climbers seem to want this conversation to end, so I'm not going to take the time to detail my thoughts on these unless requested. Briefly, my preference goes from top to bottom, with the Mooselette equalizing the best and being quickest to set up (once you get accustomed to it, and in situations where it's appropriate), CharlesJMM rig being in the middle, and two crossed slings taking the longest to set up, and equalizing the worst.
Cheers,
GO
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rgold
Trad climber
Poughkeepsie, NY
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Jan 17, 2007 - 07:52pm PT
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GoClimb wrote: I didn't say he thought the discussion was impertinent, he said that.
The I-word wasn't used by Largo. It was Wootles who said
...as much as you all love to bust on rc.com everything is pretty well covered over there, that is if you can wade through the 1000 or so impertinent posts.
GoClimb wrote: As for why he would be so dismissive of all ideas but the one presented in the book, I admit - I really can't (and shouldn't presume to) answer that question.
Since the quote isn't from Largo, you are relieved of even presuming to to figure out why he said it. Meanwhile you have let stand your claim
Of course, they won't sell any books...Apparantly the fact that they just might save lives seems not to be as important.
which says that Largo, who never said what you say he said, is by virtue of those misappropriated words more concerned about book sales than human life.
Moreover, even though they aren't Largo's words, the quote itself, far from being dismissive, clearly expresses the author's appreciation for the rc.com thread, even in the face of this site's reflexive inclination to denigrate anything from rcNOOB.com. The I-word supplies a touch of irony and can hardly be read as a "tarring of the entire discussion."
Largo obviously could care less, but I still think a real apology would still be the decent thing to do here, not that decency is particularly high on any list of internet discussion desiderata.
..........
By the way, to return to the topic at hand and highlight a point Largo made previously, in 49 years of climbing I've had to hold one factor 2 fall directly onto the belay. The anchor was a single 1" angle, pounded zealously into a perfect horizontal crack. The belay was, of course, a hip belay.
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healyje
Trad climber
Portland, Oregon
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Jan 17, 2007 - 08:02pm PT
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"By the way, to return to the topic at hand and highlight a point Largo made previously, in 49 years of climbing I've had to hold one factor 2 fall directly onto the belay. The anchor was a single 1" angle, pounded zealously into a perfect horizontal crack. The belay was, of course, a hip belay."
I can't speak to the fall factors involved, but I've held a few hard drops directly on to hip belays. I'm always categorically stunned - stunned - at the number of [smart, experienced] folks who have never hip belayed who don't consider it a "real" belay. For the uninitiated, hip belaying when done right is highly effective, can be fairly technical and is best considered integral with a more technical perspective on stancing than is commonly in evidence today.
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WBraun
climber
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Jan 17, 2007 - 08:20pm PT
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Well ....
To tell you the truth, I'm so glad I don't have to hip belay no more. You have to be so damn attentive to the point of being anal to do it properly so that if a fall does occur that the rope doesn't rip out of my hands.
So glory hallelujah rgold, the one f'ckin pin held. Why did we all even live through that crazy sh#t we did back then?
Now I'm scared to belay without my grigri and have to tie off 10 twigs instead of just one .......
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maldaly
Trad climber
Boulder, CO
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Jan 17, 2007 - 08:25pm PT
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With all due respect....I'm starting to feel like I'm over at rc.com.
Lot's of good stuff here but I'm with nutjob, despite the unfortunate handle. If the rock is good and the anchors sound, I place two down (EQ'd) and one up. Tie in with the rope, twnsion with a clove hitch and swing leads.
I'm not dead yet.
Mal
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rgold
Trad climber
Poughkeepsie, NY
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Jan 17, 2007 - 08:29pm PT
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Now I'm scared to belay without my grigri and have to tie off 10 twigs instead of just one .......
Y'know, I recently tied off ten twigs for a belay anchor and caught a load of flak for it. Man, those twigs were bomber!
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