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vivalargo
Dec 8, 2005, 9:31 PM
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A) How do you determine the direction of pull on a given climb.
B) How do you fashion your anchor to safeguard against the direction of pull.
C) The liability of NOT fashioning an anchor against the direction of pull.
D) Static vrs. dynamic equalized rigging systems for safeguarding the direction of pull.
Thanks,
JL
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crazywacky
Dec 8, 2005, 10:12 PM
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In reply to: A) How do you determine the direction of pull on a given climb.
I try, however unfortunately it affects the rest of my climb, to mentally calculate where I'll go if I fall before I place my next piece. I imagine this is similar to most other people's methods, but cannot say for sure. I learned gear placement through trial and error... Luckily no major errors, but I definitely learned how not to place a stopper.
In reply to: B) How do you fashion your anchor to safeguard against the direction of pull.
I'm a big guy, and I've found it very unlikely that my skinny little ropegun is going to pull me upwards from an anchor. So I don't typically bother.
However, if I'm leading a pitch, I'll leave a good placement, usually a cam, strategically placed so as to hold my belayer at the anchor, and not let me pull him and the gear skyward as I take my prospective whipper. This will be a piece separate from the main anchor system, attached to him by runner or daisy chain. I try to keep it so that it's not bearing weight unless he is lifted.
In reply to: C) The liability of NOT fashioning an anchor against the direction of pull.
The biggest liability, and the one I think we should be guarding against, is letting the leader take a whipper, and then take the belayer along for the ride.
In reply to: D) Static vrs. dynamic equalized rigging systems for safeguarding the direction of pull.
Sorry, but I've got no answers for this one. I can postulate that the combination of Cordelette and Sliding X might come in handy, but then we have to re-visit the the other post to find the best methodology for that.
Thank you for the questions. As I work out what I actually do when I'm on the rock, it helps me evaluate how I may need to change certain practices or maybe actually practice at all. :-)
Later,
Scott
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philbox
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Dec 9, 2005, 1:10 AM
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In reply to: A) How do you determine the direction of pull on a given climb.
I`m presuming that you are asking in regards to when the leader arrives at a belay and is about to set up the anchor. In that case I will simply look at where my rope has come from and set the anchor for that direction. Of course if the pitch below wanders after the last piece then that will have an effect on how I set the anchor. Mostly though I will pretty much set the anchor so that the direction of pull is straight down although upon reflection this does not always work as the terrain immediately below the anchor will determine where the rope will lay. For instance there may be a notch in the ledge that will determine that even if the second takes a swinging fall the rope will stay put. I will then set the anchor for the pull to occur towards where the rope will naturally lay in the notch.
In reply to: B) How do you fashion your anchor to safeguard against the direction of pull.
Snake pro should be used just before the top out, this will ensure that no falls are encountered by the leader in case of any nasty surprises on the top of the current pitch. This will also double up as a directional for the second and the rope will always be maintained in the correct orientation of pull until just before the second arrives at the anchor. Of course it is not always possible to get snake pro in so one has to do the best with what one is handed by mother nature. If the last piece is a ways down and the pitch then wanders a little then a swinging fall or pendulum then may be a possibility. Edge protection than may be a requirement.
In reply to: C) The liability of NOT fashioning an anchor against the direction of pull.
For bringing up a second I don`t see that there is that big a liability. The fall factors are extremely low.
In reply to: D) Static vrs. dynamic equalized rigging systems for safeguarding the direction of pull.
Dynamic equalisation may not be needed for bringing up a second. I`ve not experienced the conditions for when this may be required.
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tradmania
Dec 9, 2005, 1:59 AM
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In reply to: In reply to: B) How do you fashion your anchor to safeguard against the direction of pull. Snake pro should be used just before the top out, this will ensure that no falls are encountered by the leader in case of any nasty surprises on the top of the current pitch.
What is 'snake pro'? I have never come across that term before.
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philbox
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Dec 9, 2005, 2:11 AM
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Snake pro is the piece that you put in before you get to the topout or a ladege. This is put in in case there is a snake sitting on the ledge that you are just about to reach. A lot of people will run it out on the easieir ground near the top of a route. Caution needs to be exercised in case you come across a surprise at the top. Thus the snake pro.
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tradklime
Dec 9, 2005, 4:57 PM
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My guess is that John is referring to concerns in establishing an anchor for belaying the leader, not so much the follower/ 2nd.
In all honesty, the majority of my anchors consist of good pro, a good stance, and the rope. In this situation, I feel confident that I can handle all loads in all likely directions. While true equalization isn't always happenning, between rope stretch, the fact that all pieces are indivually bomber, and using my body weight against the direction of pull, I am comfortable. I guess this falls into the category of determining "liability". It's all about risk assessment and making your own decision based on the situation, incuding time and efficiency.
In the somewhat rare instance that my belay anchor is suspect, it also seems to be accompanied with a lack of options, so you really kind of just deal with what you have, and maintain optimism.
I feel that you can usually anticipate the general direction of the climbing above the anchor by just looking at the rock. If I feel there is a need for an oppositional piece, I will rig the anchor with the oppositional piece appropriately, if it is possible. But in my experience this is rare. I am usually most concern with rigging the anchor against the factor 2 fall, and feel much better when the leader gets some good pro in, the sooner the better.
I tend towards "dynamic" equalization when I set a power point anchor. However, I rarely set a power point style anchor, when I do, it is usually with a group of 3. Therefore, with multiple people hanging on the same anchor, I am more concerned with a shifiting load. I use knots to limit extension. I also often incorporate dynamic equalization into my rope anchors when I want to equalize two, less adequate pieces.
John, I really don't envy you in writing books like this, and I applaud your efforts. If I wrote a book on anchors, it would probably be one page that says: "It depends on the specific circumstance, rely on your experience to make the best judgement. If you don't have the appropriate experience, get it under the direction of an experienced mentor."
Obviously, my "book" would be worthless.
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vivalargo
Dec 9, 2005, 5:22 PM
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In reply to: My guess is that John is referring to concerns in establishing an anchor for belaying the leader, not so much the follower/ 2nd. In all honesty, the majority of my anchors consist of good pro, a good stance, and the rope. In this situation, I feel confident that I can handle all loads in all likely directions. While true equalization isn't always happenning, between rope stretch, the fact that all pieces are indivually bomber, and using my body weight against the direction of pull, I am comfortable. I guess this falls into the category of determining "liability". It's all about risk assessment and making your own decision based on the situation, incuding time and efficiency. In the somewhat rare instance that my belay anchor is suspect, it also seems to be accompanied with a lack of options, so you really kind of just deal with what you have, and maintain optimism. I feel that you can usually anticipate the general direction of the climbing above the anchor by just looking at the rock. If I feel there is a need for an oppositional piece, I will rig the anchor with the oppositional piece appropriately, if it is possible. But in my experience this is rare. I am usually most concern with rigging the anchor against the factor 2 fall, and feel much better when the leader gets some good pro in, the sooner the better. I tend towards "dynamic" equalization when I set a power point anchor. However, I rarely set a power point style anchor, when I do, it is usually with a group of 3. Therefore, with multiple people hanging on the same anchor, I am more concerned with a shifiting load. I use knots to limit extension. I also often incorporate dynamic equalization into my rope anchors when I want to equalize two, less adequate pieces. John, I really don't envy you in writing books like this, and I applaud your efforts. If I wrote a book on anchors, it would probably be one page that says: "It depends on the specific circumstance, rely on your experience to make the best judgement. If you don't have the appropriate experience, get it under the direction of an experienced mentor." Obviously, my "book" would be worthless.
Yeah, it's a pain in the ass. The temptation is to short hand the info instead of talking the stuff all the way through, which involves a lot of equivocal stuff and few absolutes. But I'm getting there.
JL
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iclime
Dec 9, 2005, 5:44 PM
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A: Unless the gear is suspect, I expect the pull to be toward the first piece of gear (belaying the leader) or the last (belaying a second).
B: I agree strongly with this:
In reply to: Snake pro should be used just before the top out, this will ensure that no falls are encountered by the leader in case of any nasty surprises on the top of the current pitch. This will also double up as a directional for the second and the rope will always be maintained in the correct orientation of pull until just before the second arrives at the anchor.
C: To me, this is mostly a liability when you're using a static equalization method (most cordellete or rope setups). I'll assume that you're talking about some specialized circumstances--traverse, perhaps?--because I think just about everyone figures that the anchor should sorta point towards where the big cord thingy is about to go or where it just came from.
The liability comes from suspect gear and a desire to retain equalization. If you don't predict the the direction very well, you risk hanging you and your partner's butts off of one or maybe two pieces. I have personally encountered this primarily when I top out on a climb and have to go searching for anchor prospects, thus ending up somewhere other than right on top of the last piece.
D: As I said in C, as long as a dynamically equalized system is mostly pointed towards the climb, the direction of pull is accounted for (at a cost to other concerns, see your whole other post on this topic, John). I will say that even when this is a concern, I still usually opt for the cordellette option. I feel like it keeps the integrity of the anchor system more predictably.
M
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xp
Dec 12, 2005, 8:24 PM
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Is it not the case that the direction of pull is the line that bisects the angle between the rope coming in and the rope goint out? Unless there is only one strand coming in, in which case it is the direction where it comes from.
So an anchor that has the belay device attached to it (e.g. bringing up a second or the belayer being attached to the anchor while the leader takes a factor-2 fall before reaching the next anchor) will see just a downward pull, or whereever the load ends up falling. Once the leader clips the next piece, the anchor may see a pull towards that piece, assuming the belayer will be pulled up high enough to load the anchor.
Now, if the belayer is positioned some distance away from the anchor in order to prevent the pure factor-2 fall, that anchor itself might be called the 1st piece. In that case a fall before the next anchor will load that 1st anchor somewhere half-way between down and the direction of the belayer. So the rightmost piece of the anchor better be good. Once the leader clips the next piece, and assuming it holds, the anchor will be loaded towards a line lying somewhere between the belayer and the direction towards that next anchor. Say the belayer is on a horizontal ledge and left of the anchor. The pitch goes up. The load will be somewhere 45 deg. up and to the left. That nut that makes the lefmost part of the anchor can easily fly out of place, uless there was a directional down and to the right. The wider the angle, the less the outward force on the anchor, but it can still be enough to pull out a less secure piece. If the angle is 180 degrees, i.e. the anchor is perfectly in line between the two adjasent ones, there is no pull at all.
The pull on an intermediate anchor may not matter much if the top anchor (on which the leader falls) holds, but a failure of an anchor that has the rope form an angle when passing through it will add fall distance. And if that top piece held just long enough to dislodge the rest and then failed...
Does any of this make sense, or is this Dilbert's attempt to safeguard a climb?
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vivalargo
Dec 15, 2005, 11:45 PM
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That makes perfect sense--the hard part is imparting same in such bonehead language that even my dog can understand and "see" it right off.
Thanks,
JL
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billcoe_
Dec 16, 2005, 9:27 PM
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In reply to: A) How do you determine the direction of pull on a given climb. B) How do you fashion your anchor to safeguard against the direction of pull. C) The liability of NOT fashioning an anchor against the direction of pull. D) Static vrs. dynamic equalized rigging systems for safeguarding the direction of pull. Thanks, JL
What kind of funky crap is this.
John, you already wrote that book. To show up and ask nameless posters (some of who may have learned everything they know on this site) technical questions is turning my world upside down.
Upside down I say.
Regards:
Bill
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el_jerko
Dec 17, 2005, 2:33 PM
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As a nameless poster I swear I have learned very little of value on this site and therefore feel fully qualified to post an answer.
I am not sure this is the way one should approach the problem, but I attempt to use body english to varying degrees.
Belaying the follower:
In situations where the rope is coming strait off my harness (often the case when extending the anchor to get out on the edge to see the climber) I want to be in a position where I, not the follower, am supported by an equalized anchor. I might be directing the rope in a different direction, but it is more important to me to be comfortable and unencumbered. To do this I might rely on braced legs or simply ass to rock friction i.e. body english. To summarize, when belaying off my harness I equalize the anchor to support me, and I vector the rope.
Belaying the leader:
The ideal situation obviously would be to have the anchor aimed strait at the first piece of gear and your belay device in between. When this is not the case, I think of my body weight as being the first line of defense. I try and position myself such that the falling leader has to move my weight (braced if possible) before the force hits the anchor at an un-equalized angle. It is pretty common for belayers to catch falls without exerting any force on the anchor. I try and position myself so that there is no slack between myself and the anchor, and that the initial force will be directed to the anchor at an equalized an angle as possible. I also want to be situated so that I am not going to hit anything if I am jerked out of position. In the couple of instances that I can recall being jerked up completely out of my belay stance by a high fall factor I feel my weight kept a great deal of the energy from reaching the anchor.
Again, I am not sure this is the way one should approach anchoring, but I think throwing your weight around makes a significant difference and every little bit helps.
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billcoe_
Dec 18, 2005, 12:47 AM
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See?
:D :D :D :D :D :D :D :D :D :D :D
You all know I'm just kidding here?
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rgold
Dec 18, 2005, 3:57 AM
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The only way to equalize three or more pieces is to rig some sort of sliding system like the Trango Equalizer. True equalization, meaning more or less the same load imparted to each piece, can only be obtained via the "block and tackle" effect of strands that are free to move. Sliding systems that have stopper knots to limit extension are no longer equalized and distribute the load according to their geometry when they are loaded. The load distribution need not be "nearly equal" at all. For example, a standard three-piece set-up, rigged with a cordelette or a sliding system with stopper knots, with the three pieces equally spaced in a horizontal crack, will, if perfectly tied, place about 1/3 greater load on the middle piece than on either of the two end pieces when the angle between the outer pair of strands is 60 degrees.
Fixed cordelette-style anchors will typically load a single piece if they are subject to a force in a different direction from the one they were tied to resist. (They may load a single piece in any case, just because they cannot be perfectly tied.) Sliding systems with stopper knots will adjust their geometry and so will continue to distribute forces within their range of motion, although the distribution will not, in general, be an equal one and can, I should empasize again, be quite unequal.
For any particular rigging geometry, it is possible to calculate the load distribution, but there is not a whole lot of practical value to be obtained from such calculations beyond the realization that each individual piece in the anchor really needs to be good and the angles need to be kept small. When this isn't the case, as is sometimes unavoidable, the behavior of the anchor will be pretty hard to predict and I don't think total failure under a big impact is an unlikely outcome.
If the individual pieces aren't really good, then it seems to me (I have to admit that I'm trying to think about this objectively for the first time in a very long climbing career) that a true equalizing system is by far the best bet. (And make no mistake, betting is the right analogy here.) The trick is to have such a system without the potential for a big extension if a piece fails. (You can't have no extension and achieve equalization.) The way to do this is to have a sliding system with arms as small as possible, joined to the actual pieces by slings. (This is the "right" way to limit extension in an equalized system, not by stopper knots that prevent equalization from happening.) Trango actually sells a "short" equalizer that might fit the bill very well, although I haven't seen it in the flesh. I think the short Trango equalizer would have 6" arms for a three-piece anchor, and if one of these failed there'd be a 3" extension. You can rig up something analogous from slings or even with just the rope, but a fair number of biners will be consumed. Even with the short Trango unit, a three-piece anchor will consume six biners, not including the power point biner.
The days of "the leader must not fall" are long gone, but "the leader must not fall directly onto the anchor" is a pretty good try at an absolute, given that we now live in the era of "it depends." Routes with mandatory run-outs on difficult ground above less than perfect anchors are more than X-rated. They are XX or XXX rated, depending on whether there are two or three climbers in the party.
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tradklime
Dec 19, 2005, 5:12 PM
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rgold, thanks for adding to the discussion.
In reply to: Sliding systems that have stopper knots to limit extension are no longer equalized and distribute the load according to their geometry when they are loaded.
Would you mind expanding on this a little? If we are talking about a sliding-x with extension limiting knots (or multiple sliding-x's to deal with more than 2 pieces) and we are within it's range of motion, how does that really differ from the following:
In reply to: The way to do this is to have a sliding system with arms as small as possible, joined to the actual pieces by slings. (This is the "right" way to limit extension in an equalized system, not by stopper knots that prevent equalization from happening.)
Are you saying it is better equalized due to reduced friction? The trango system will have a limited range of motion, just as the sliding-x's with knots do.
Thanks
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el_jerko
Dec 19, 2005, 5:18 PM
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rgold,
I am interpreting the gist of what you are saying to be that every anchor is essentially a one piece anchor with backup. The other legs of the anchor do not significantly contribute until the primary piece is failing. That being the case should we be building anchors using a different philosophy? The most bomber piece on the shortest leg, the next best piece the next shortest and so on?
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rgold
Dec 20, 2005, 5:34 AM
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TK, it isn't the limited range of motion that is the main point. The question is whether the strands of the sliding system are free to run through all attachment points. If they are, then they will equalize the load. If stopper knots prevent the strands from running, then the load will be whatever is determined by the geometry of the anchor configuration when it is loaded.
Perhaps another way to put it is that there are three types of anchors: Distributed non-orientable (the cordelette), where by non-orientable I mean that distribution occurs only in the direction the anchor was tied for, and most other directions load a single piece, distributed orientable (sliding systems with stopper knots), which means the anchor has some ability to adjust for the direction of load but the load is still distributed to the anchors in a possibly unequal way, and equalized (sliding systems without stopper knots), which equalize the load to all anchors and can orient a range of directions. In counterpoint to the growing list of advantages listed above is a list of increasingly severe extensions if a piece in the system fails.
My comment about the "right" way to equalize was that one ought to use slings to bring all the pulley biners close to a single point and then use a sliding system with relatively little total sling length, so that extension, though not prevented, is minimized. As I said, this may not be very practical in terms of speed of rigging or gear consumption.
EJ, I think most anchor set-ups distribute the load to some extent, unless the pull comes from an unanticipated direction. (If you weight the anchor and there is tension in all the strands, then there must be a load distribution.) The trouble is, in the field it is hard to judge what the distribution will be, not only because of the complexity of the ideal situation but also because in tying the various knots, the absolutely correct arm lengths will not be achieved. As a rough rule of thumb, it is probably true that in most set-ups the shorest strand will develop the highest tension, although the angle of the strands has an effect that counteracts this, and it is hard to know whether the extra tension will be enough to matter.
The real problem happens with less than bombproof anchors. Some people speak as if these never happen, or if they do, that they are prima facie evidence of climber incompetence. But I think anyone who has spent much time climbing will recall having to build anchors where no piece was bombproof. My only practical point is that we shouldn't lull ourselves into a false sense of security by imagining that we can "equalize" such anchors with a simply rigged set-up and thereby make the anchor reliable for big loads. On the other hand, the art of anchor-building still strives for the best solution under the circumstances.
Whether one's judgement about the relative solidity of the various pieces should influence the way the anchor is rigged is an extremely difficult question. There is a simple case that may be worth mentioning: If you have two solid pieces and a not-great piece in a more or less horizontal line and if the not-great piece is leftmost or rightmost, then rather than rigging the cordelette in the usual manner with the center strand running vertically from the knot to the middle piece, it would be better to "skew" the rigging so that the knot is located between the two good pieces, as it would be if there were only the two good pieces. The reason for this is that if the cordelette is rigged in the standard way and the not-so-good piece blows, then the load is transferred entirely to the middle piece and the second good piece does nothing unless the middle piece fails too.
I wish that someone with a bunch of load cells would rig a whold bunch of anchors (with three or more anchor points) and do some pull tests to get a sense of how the loads really distribute in with real set-ups tied by real people.
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