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Ed Hartouni
Trad climber
Livermore, CA
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Nov 26, 2008 - 10:21pm PT
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the power of a scientifically correct analysis is that it does not depend on common belief, rather, it has to be explainable in a rigorously logical manner and obey physical law.
That being said, most climbers do not care or think about the forces involved in a rare fall (unless you're climbing with Pat, apparently - humor). Instead, climbers utilize a "skill of the craft" approach to building anchors. How you lean this, and what you lean is very dependent on who your mentor is... many of us learned it from someone who was an experienced climber, usually the older ones of us... many others learned it from a book.
What most of us have in common is that we have not been tested on the anchors that we have built. Over the last 13 years I've built 1000s of anchors. In most cases they were not tested by large force falls. Does that mean that all those anchors would have protected me and my partners in the event of a large force fall? I have no way of knowing.
I do pretty much what everyone else does:
 Be thoughtful about where the belay should be with respect to bringing up the second, and belaying the leader on the next pitch.
Select features in the rock that have mechanical integrity, and are not mechanically related.
I try to get three anchor points in, where any of those three would hold the entire fall.
I usually try to "equalize" the anchor system so that the forces are distributed on multiple anchors.
Get a piece of pro in very close to the belay, "protect the belay" I say, where that piece will hold a fall all by itself.
These days I do this all pretty quickly. It is informed by scientific analyses I have done and it doesn't look a whole lot different than what I believe is taught (though there is a difference between what the teacher thinks was taught and what the students learned, especially if there are no tests).
Answer the OP question? "Should the leader clip the belay anchor?", of course it depends. If you can get another piece in, do that. If it is a 3/8" bolt, probably fine to clip... if things are dicey enough to make you worry, then you have to think the whole anchor is sketchy and you have to be really careful leading out to that first piece, or if that isn't possible, maybe just backing off, or moving the belay to a better place.
We make all these choices largely based on our experience and our willingness to accept risk, risk that may not be calculable.
The geeks do have to listen to the cool-cats, but the cool-cats should listen to the geeks as well, good information all around.
Unfortunately, there is very little real good work done to examine our practices. jstan did once upon a time, and Wootles (avatar RIP) had also... we have the misfortune of worrying about this only when one of ours has made a fatal miscalculation...
...then we move on.
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JohnRoe
Trad climber
State College, PA
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Nov 26, 2008 - 10:39pm PT
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I ran some numbers (numerical integration of the equations of motion). These need checking when I am more awake, but they seem plausible. (Edited to give a more plausible rope modulus.)
Karl asked (in the equalette thread)
"1. Let assume the leader clipped the powerpoint of a cordalette anchor as a directional, climbed up 15 feet and fell. The belayer is also hanging low on the cordalette.
versus
2. The belayer is hanging there and belaying off the powerpoint with a gri-gri (assume static belay even though they slip a bit)
How much pully effect in #1 versus #2"
Here are 3 scenarios. In each scenario the belayer is hanging 1 meter below a power point and has 4 meters of rope out to the leader. Assume rope modulus=11.2kN (EDITED) and coeff of friction round top piece = 0.6 Assume 80kg climber and belayer
Scenario 1. No runner: factor 2 fall onto the belayer.
In this case the peak retarding force on the falling climber of 6.8kN is generated 287ms after impact. The peak force on the anchor is then 7.6kN (retard force + weight of belayer)
Scenario 2. Runner through the power point; belayer static (anchored for upward pull).
The peak retarding force on the falling climber is now 6.2kN, 283ms after impact (slightly lower b/c of lower fall factor). The peak force on the anchor is 1.6 times 6.2kN, that is, 9.9kN.
Scenario 3. As scenario 2 but no upward pull anchor; belayer is hanging.
This is the softest catch because the upward movement of the belayer absorbs some force. The peak retarding force on the falling climber is now 5.2kN, generated 228mS after impact. At this instant there is an additional 3.1kN on the belayer, who is headed upwards at approximately 3.5m/s. Thus, the peak total force on the anchor is 8.3kN, still more than in scenario 1. After 372ms, the belay device gets sucked at high speed into the biner on the power point. I didn't attempt to write any equations for what happens after that :-)
I can run more of these if anyone wants (or someone else should check them!) All of these impact forces would be bad news; perhaps we should try again with less rope out. (Edit: looks more realistic now the rope modulus is corrected)
JohnR
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Patrick Oliver
Boulder climber
Fruita, Colorado
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Nov 27, 2008 - 12:20am PT
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I still don't use a belay device and prefer a hip belay, with a carabiner to clip the leader's rope on my swami on the opposite side of the brake hand. Probably sounds archaic, but it has always worked. I mention this only because clipping the anchor would be a bit redundant, in most cases, or unnecessary, with my system and might put the burden of a fall more on the anchor than on me. Unless the anchor is really bombproof, and maybe a triple anchor kind of thing, I can't really imagine clipping the lead rope into it, as I would rather trust myself to hold a fall and let the belay anchor back me up and anchor me to the belay place. I feel a little like someone from the stone age talking to the modern world. I can't imagine anyone would pay any mind to what I say. But they used to call me the master of safety -- an honor in some circles and a dubious distinction in others...
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crøtch
climber
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Nov 27, 2008 - 12:47am PT
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"I feel a little like someone from the stone age talking to the modern world."
I'm enjoying this glimpse into the mind and ways of australopithecus eldoradus.
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nick d
Trad climber
nm
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Nov 27, 2008 - 12:58am PT
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As ususal, Mr.Stannard asks the most pertinent question.
Answer up, wannabes! If you dare.
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Curt
Boulder climber
Gilbert, AZ
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Nov 27, 2008 - 01:18am PT
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It's simple. rgold is correct in theory and jstan is correct in practice.
Curt
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Karl Baba
Trad climber
Yosemite, Ca
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Nov 27, 2008 - 01:23am PT
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John, if you could run one more scenario, Factor two fall when the belayer is belaying with a gri-gri directly off the powerpoint, but is hanging on the anchor. (possible aid climb scenario)
Thanks
Pat wrote
"I feel a little like someone from the stone age talking to the modern world."
How much are you of the school of "the leader must not fall!"
It's got to be hard to catch a factor 2 fall with a hip belay when the leader falls behind you and all that force rips into a carabiner clipped into your swami (anything to keep it from sliding back your swami?)
It's true in the modern age that many climbers are more willing to fall long and hard and this just won't wash anymore. I took a factor two fall past my belayer using a hip belay BITD on the second pitch of Mud Flats and it burned his hand.
Peace
Karl
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rgold
Trad climber
Poughkeepsie, NY
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Topic Author's Reply - Nov 27, 2008 - 01:51am PT
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Uh, Karl, the calculations you just thanked JohnR for use the very same pulley effect (mitigated by friction, as I also suggested) you just got done denying. Maybe you're just picking on me? (Boo hoo!)
I did the same calculations about a year ago, including also the break-even ones whose mention seemed to start this debate. I'll have to go back and look at them, but I remember the numbers coming out a little lower, quite possibly because I chose different parameters to start with. John gets a factor two peak load of 14.8 kN, which is well above the UIAA limit for single ropes, and the fall factor of 2 rather than 1.78 wouldn't account for this, if, say, you start out with a rope with UIAA impact force of 9 kN. (I know, they come out of the box with less than that, but on the other hand are almost certainly not that resilient in the field, especially after a little use.)
Happy Thanksgiving everyone. May your anchors, clipped or not, and the rest of your lives for that matter, live up to all your fondest expectations.
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Ed Hartouni
Trad climber
Livermore, CA
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Nov 27, 2008 - 01:54am PT
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have a great thanksgiving Richard,
berg heil!
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WBraun
climber
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Nov 27, 2008 - 01:55am PT
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May your anchors, clipped or not, and the rest of your lives for that matter, live up to all your fondest expectations.
I like that line, and thanks Richard for just being here.
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SteveW
Trad climber
The state of confusion
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Nov 27, 2008 - 02:09am PT
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Wonderful information, you smart people.
I try to do it as you say, and fortunately through the
years it hasn't been tested to the limit.
This is a valuable thread and should be required reading.
Thanks!
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Patrick Oliver
Boulder climber
Fruita, Colorado
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Nov 27, 2008 - 08:35am PT
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Karl,
In a few hundred thousand climbs I've never had that happen, to have someone fall behind me and rip a carabiner around the back. If they first of all start with some kind of decent piece of protection, that won't happen. But if they have to run it out right off the belay, then I position myself so as to be in the right place and facing the right way. Maybe that sounds self-righteous. I hope not. But also if the carabiner is in the right place, it tightens where it is and doesn't slide. It sometimes amazes me when I climb with people who have all the newest gear and gadgetry who can't comprehend how I could survive using the system I do. We weren't so much from the school of "the leader shall not fall" as much as that the leader and belayer work together, that competence and technique and ability to downclimb, and creative ability to protect, and things such as judgment, etc.... contribute to the safest possible ascent. Even on a climb such as Twilight Zone, the safety was in the leader's ability. Pratt's protection was his skill more than any equipment. I would venture a pretty comfortable guess that I am able to belay with my archaic system as well as any climber around with more modern methods. But it takes a few years to learn all the things one needs to know, regardless of the methods you use. It's just another area of mastery one has to achieve. I have known very good climbers who were almost incompetent at certain basics, such as the proper belay... Sacherer was kind of an example of this. He could do those hard pitches but was famous for making mistakes at belaying, anchoring, protecting others, etc.
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TradIsGood
Chalkless climber
the Gunks end of the country
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Nov 27, 2008 - 09:32am PT
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JohnRoe,
If the belayer's fingers are on the rope above the belay device (non-brake hand), I can tell you what happens. He likely was already gripping the rope and is more likely to squeeze harder in the short instance he has than to let go. It's too late to let go by the time he realizes the error. He gets a compound fracture of the finger that hits the power point, and likely complete tears of tendons (or worse). The next finger down may be injured as well, but much less likely to be fractured. How well the hand can be repaired depends.
The pain will cause him to check his hand to see if the finger was severed. We hope that he retains a grip with the brake hand.
Anyway, Happy Thanksgiving.
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Paul Martzen
Trad climber
Fresno
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Nov 27, 2008 - 11:15am PT
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Happy Thanksgiving!
This is a fascinating thread, and I am really enjoying reading it. I especially appreciate Patrick Oliver's perspective and thoughts.
The position of the belayer's body is something I tend to think about also and it is not unusual for me to use my body as the entire anchor, particularly in scrambling and canyoneering situations. But I love the way you put it, Patrick, to start off thinking about where to position your body first, as if the belay had no other anchor, then go back to establishing additional anchors.
The original question of whether to clip the anchors as the first lead runner is interesting and one I don't think I have thought about much. I am going to try to follow the Geek calculations myself, but probably not before the thread dies. This discussion is giving me a bunch of interesting ideas for empirical simulations though. A question that seems really interesting is, "How big of a fall can you hold, without blowing out very weak anchors?" I have had some super weak anchors at times which thankfully did not get tested, but I recall thinking my body was a big part of the anchor system. Some of the techniques that people have suggested though, are completely new to me. Very cool.
Now I am off to go hike around Zion NP in the rain. My wife and I are visiting her father in St. George this Thanksgiving weekend.
Paul
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guyman
Trad climber
Moorpark, CA.
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Nov 27, 2008 - 11:18am PT
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““We weren't so much from the school of "the leader shall not fall" as much as that the leader and belayer work together, that competence and technique and ability to downclimb, and creative ability to protect, and things such as judgment, etc.... contribute to the safest possible ascent. Even on a climb such as Twilight Zone, the safety was in the leader's ability. Pratt's protection was his skill more than any equipment. I would venture a pretty comfortable guess that I am able to belay with my archaic system as well as any climber around with more modern methods. But it takes a few years to learn all the things one needs to know, regardless of the methods you use. It's just another area of mastery one has to achieve. I have known very good climbers who were almost incompetent at certain basics, such as the proper belay... Sacherer was kind of an example of this. He could do those hard pitches but was famous for making mistakes at belaying, anchoring, protecting others, etc.””
Really good discussion going on here, Patrick hit the nail on the head with this one. IMHO.
I have always thought that climbing is more about your brains and judgment than about the shinny newest piece of gear.
“but what do I know?” …..
Happy Thanksgiving to all.
GK
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sibylle
Trad climber
On the road again!
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Nov 27, 2008 - 11:34am PT
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One question I have, which has not been discussed much, is what if a much smaller climber is belaying much heavier leader? Such as women who weigh 100 - 130 pounds belaying much heavier men?
I've been in serious situations with this weight issue. A few years ago, my climbing partner (6'5", 215 pounds) took a very long fall, but he was close to 180 feet out, so there wasn't much impact. I'd guess he fell about 150 feet and ended up hanging below me. I was able to escape the anchor, and move up about 70 feet to his last pro (a sling around a tree), but could not move him. I had my old nuts on slung perlon, which I used as prusicks, to both escape the belay and to move up.
I talked to him below me, and tried to help him move up to a ledge, but could do nothing. He died three hours later.
I've always wondered since then what one could do, but without carrying pulleys, extra cord, stuff to make anchors, etc., not all of which the second usually carries, it's hard to raise a fallen leader.
I always clip leaders through the anchor, because they are usually heavier than me and I worry about catching someone much heavier if they fall below me and fall onto my harness.
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Ryan Tetz
Trad climber
Flagstaff, AZ
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Nov 27, 2008 - 12:39pm PT
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I didn't have time to read this whole thread but one thing that is IMPORTANT:
Have any of you seen the rigging for rescue video on the daisy chain and sling drop tests? They tested the metolious PAS too.
SPECTRA DAISY CHAINS BREAK UNDER A STATIC DROP OF 2 FEET WITH A 150LB WEIGHT!
That means just jumping off the ledge at the anchor the average guy will rip one of those in half. Take a factor 2 and you got no chance, and how many climbers do you know that use those things to anchor themselves? Probably more than you can count on both hands. Teaching them to clip the belays is the only thing holding the party from the ground if the belay has to hold a real factor 2.
The PAS, nylon, and spectra slings and daisy chains were all tested. While the fancy ones like yates daisys with screamers built in held a little higher they all failed when they dropped the 200lb weight 2 feet. Even the PAS.
The only thing that held up regularly were nylon daisies and nylon slings which many climbing shops have stopped carrying in favor of the new sexy light stuff. The rationale was that nylon stretches while the spectra and dyneema are totally static.
The only recommended tie in by AMGA guides to a single anchor is the climbing rope. A clove hitch tied correctly with the load strand toward the spine or a 8 on a bight. If don't do this you got to clip in twice with say the rope and a sling.
When I climb with half my buddies still insisting on carrying the daisy chain. I insist they tie in again to the anchor with the rope up higher or use a second sling or I will not leave the belay PERIOD.
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tito
climber
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Nov 27, 2008 - 02:30pm PT
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> SPECTRA DAISY CHAINS BREAK UNDER A STATIC DROP OF 2 FEET WITH
> A 150LB WEIGHT!
> That means just jumping off the ledge at the anchor the average guy will
> rip one of those in half. Take a factor 2 and you got no chance
So are you recommending that people not lead out on daisy chains?
> and how many climbers do you know that use those things to anchor themselves?
One.
> Teaching them to clip the belays is the only thing holding the party
> from the ground if the belay has to hold a real factor 2.
No matter how many times I read that, I have no idea what that means. Translation please?
Consider this: I clip in tight to the power point of a cordalette anchor with a daisy chain. My belay device starts slipping at 3 kN. I belay the leader directly off my waist. The leader falls before getting any pro in. Are you saying that it is highly likely that we are both going to hit the deck?
> The only recommended tie in by AMGA guides to a single anchor is
> the climbing rope.
The AMGA is now recommending single anchor belays?
> When I climb with half my buddies still insisting on carrying the daisy chain.
> I insist they tie in again to the anchor with the rope up higher or use a second
> sling or I will not leave the belay PERIOD.
What does making them clip in with a second sling get you?
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Karl Baba
Trad climber
Yosemite, Ca
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Nov 27, 2008 - 02:54pm PT
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RGold wrote
"Uh, Karl, the calculations you just thanked JohnR for use the very same pulley effect (mitigated by friction, as I also suggested) you just got done denying. Maybe you're just picking on me? (Boo hoo!) "
I thanked him for taking the time. He didn't address my scenario and it should be obvious from the numbers that he came up with that they are sheer geek numbers with little relation to reality. Obviously these anchors aren't going to get 10-20kn forces under almost any circumstance. Everything would break! Now, there is SOME chance that we can take some relative wisdom from John's numbers, just in relation to each other, but because each scenario has so many unaccounted factors, who really knows?
Theoretically, a daisy fall should break your body. I've taken a few and they didn't. It's complicated.
Which is what bugs me about these threads. The number and forces that geeks come up with just can't account for all the friction, give, and ju-ju that are all over the system so they reach conclusions that don't match the obvious. Folks should be having their anchors and belays fail all the time but those things are actually quite rare in reality.
I think the geeks would be better off studying psychology and communications, which are almost non-sciences but could be more accurate in predicting climbing dangers. What really happens? Stuff like the leader falling because he expects to be lowered from the chains while his belayer thinks a rappel is next. Stuff like slipping off the descent ledge or going off rappel before clipping the next anchor. Factors of inattention and fatigue are the real climbing killers. These geek threads have their place. I'm not saying don't write in them. You just have to put up with me interjecting this bit of disclaimer in them.
I don't deny the pulley effect, just that it doesn't double the force on the anchor and that if you are hanging on the anchor anyway and belaying through the powerpoint, it adds even less to the issue.
Which John nor you haven't really addressed. Tell me. If two guys hang on one piece using their separate daisies, how much less force is exerted on that piece than if those two guys hang on that piece using a rope that connects them? Get it?
Thanks for your response Pat. Obviously, when an experienced person does what they know within the limits of the climbing where what they know works, then they have a system that works for them. I doubt your system would be good for somebody working 5.13 routes, taking repeated 50 foot whippers, like we see on some routes these days, but then, if that were you climbing like that, I'm sure you'd adjust your gear accordingly.
Peace and Happy Thanksgiving. I'm grateful there is a God and Karma, which is why this dangerous climbing stuff doesn't kill a dozen of us a day! It's amazing there's not thousands of people dying on the highways every day!
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WBraun
climber
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Nov 27, 2008 - 04:08pm PT
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The Purcell prussik system works pretty good and is what I use for daisy on free climbs. In the example below it says use 6mm but mine is 7mm and 8mm would be even better. I'm gonna change mine to 8mm soon. Since it's fast and adjustable on the fly it's ideal and it's nylon without the problematic properties that spectra and dyneema exhibit.
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