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dugl33
Feb 8, 2011, 3:11 PM
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Rmsyll2 wrote: A question has been raised about the ability of the belayer to make a proper anchor, as indicating general competence: see Att'd. The rigging used relied on the belay loop with two carabiners not directly connected. I do not know the usual kN for those, but it is usually relied on. I don't see that as an issue here. Majid's drawing seems to show two ways to make a redirect belay; but some posters do not use that, doing it as in the first photo. I think now that an ATC is good only for rappelling, however many do use it for belay. A Reverso now seems much better for belay. Both are always a two-strand pulley, so a redirect makes a four-strand pulley? I suspect now that the accident was directly belayer error, not coordinating his hands correctly to lower under device control, however it was rigged; but that will not be known. I still don't know what should be done for a safe, reliable top-belay. Any method works perfectly -- until a climber falls. LL . Hard to say without seeing more detail. Two pieces look to rely on a somewhat detached block, and one stopper is in a pretty parallel looking crack. A three piece anchor is only solid if the components are solid.
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wwalt822
Feb 8, 2011, 3:23 PM
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Was the belayer perhaps only trained in the use of the BUS belay method?
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dugl33
Feb 8, 2011, 3:27 PM
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Rmsyll2 wrote: D. explained that the problem with the rigging was the direct connection of the rope to A., instead of the rope being put through an master-point at the anchor and then through the device, similar to how it is from the ground.* My understanding of his point is that making a two-strand pulley divides the force on the device in half. You are confused with regards to the mechanical advantage of "pulleys". Belay devices add friction, that's it. They reduce the force needed by the braking hand in comparison to the pull on the load side. A top redirect may add a little more friction but does not provide a mechanical advantage as far as braking. It does put the belayer in a more comfortable orientation for braking and tends to lift him up toward the redirect, rather than down.
Rmsyll2 wrote: Majid's drawing seems to show two ways to make a redirect belay; but some posters do not use that, doing it as in the first photo. I think now that an ATC is good only for rappelling, however many do use it for belay. A Reverso now seems much better for belay. Both are always a two-strand pulley, so a redirect makes a four-strand pulley? I think you are still confused. What is shown in Majids drawing on the left is a way to use a standard atc connected directly to the anchor for a lower. The purpose of the redirect biner here is to orient the pull of the brake strand in the standard lock off orientation, otherwise the strands tend toward parallel and the belayer would have to pull up on the brake strand (weak, awkward, poor control) rather than downward (strong, comfortable, in control). *edit to add context
(This post was edited by dugl33 on Feb 8, 2011, 3:46 PM)
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wwalt822
Feb 8, 2011, 3:39 PM
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In a frictionless world redirecting would double the force on the anchor. Belaying off the harness with a redirect through the anchor nearly doubles the force on the anchor except for the friction of the redirect biner. Belaying off the anchor with a redirect back through the anchor doubles the force minus the friction of the redirect biner and minus the friction of the belay device. Or another way of looking at this is you will have the weight of the climber plus the force of the brake hand on the anchor.
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shoo
Feb 8, 2011, 3:45 PM
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wwalt822 wrote: In a frictionless world redirecting would double the force on the anchor. Belaying off the harness with a redirect through the anchor nearly doubles the force on the anchor except for the friction of the redirect biner. Belaying off the anchor with a redirect back through the anchor doubles the force minus the friction of the redirect biner and minus the friction of the belay device. Or another way of looking at this is you will have the weight of the climber plus the force of the brake hand on the anchor. OMG! It could DOUBLE an extremely small amount of force relative to anchor strength in a scenario so unrealistic as to by totally irrelevant all while making belaying massively more difficult?!?! I MUST WARN THE INTERNETS!!!!
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vegastradguy
Feb 8, 2011, 3:51 PM
Post #32 of 151
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dugl33 wrote: Rmsyll2 wrote: A question has been raised about the ability of the belayer to make a proper anchor, as indicating general competence: see Att'd. The rigging used relied on the belay loop with two carabiners not directly connected. I do not know the usual kN for those, but it is usually relied on. I don't see that as an issue here. Majid's drawing seems to show two ways to make a redirect belay; but some posters do not use that, doing it as in the first photo. I think now that an ATC is good only for rappelling, however many do use it for belay. A Reverso now seems much better for belay. Both are always a two-strand pulley, so a redirect makes a four-strand pulley? I suspect now that the accident was directly belayer error, not coordinating his hands correctly to lower under device control, however it was rigged; but that will not be known. I still don't know what should be done for a safe, reliable top-belay. Any method works perfectly -- until a climber falls. LL . [Image]http://www.rockclimbing.com/cgi-bin/forum/gforum.cgi?do=post_attachment;postatt_id=5526[/image] Hard to say without seeing more detail. Two pieces look to rely on a somewhat detached block, and one stopper is in a pretty parallel looking crack. A three piece anchor is only solid if the components are solid. If i rolled up to a ledge and saw that, i'd be doing some damn close inspection before I trusted it...
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dugl33
Feb 8, 2011, 3:55 PM
Post #33 of 151
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wwalt822 wrote: In a frictionless world redirecting would double the force on the anchor. Belaying off the harness with a redirect through the anchor nearly doubles the force on the anchor except for the friction of the redirect biner. Belaying off the anchor with a redirect back through the anchor doubles the force minus the friction of the redirect biner and minus the friction of the belay device. Or another way of looking at this is you will have the weight of the climber plus the force of the brake hand on the anchor. I understand this but this is not the nuance of what was being implied by the OP. The OP referred to a non-existent mechanical advantage to braking, not a genuine mechanical disadvantage on the anchor. Reread the post...
Rmsyll2 wrote: D. explained that the problem with the rigging was the direct connection of the rope to A., instead of the rope being put through an master-point at the anchor and then through the device, similar to how it is from the ground.* My understanding of his point is that making a two-strand pulley divides the force on the device in half. The bolded part is incorrect and suggests a 2:1 mechanical advantage with regards to braking where none exists, at least in your frictionless world. See the difference?
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wwalt822
Feb 8, 2011, 4:02 PM
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shoo wrote: wwalt822 wrote: In a frictionless world redirecting would double the force on the anchor. Belaying off the harness with a redirect through the anchor nearly doubles the force on the anchor except for the friction of the redirect biner. Belaying off the anchor with a redirect back through the anchor doubles the force minus the friction of the redirect biner and minus the friction of the belay device. Or another way of looking at this is you will have the weight of the climber plus the force of the brake hand on the anchor. OMG! It could DOUBLE an extremely small amount of force relative to anchor strength in a scenario so unrealistic as to by totally irrelevant all while making belaying massively more difficult?!?! I MUST WARN THE INTERNETS!!!! Did I say there was a problem with doing it any of these ways? And the only unrealistic scenario is the frictionless one. Someone was confused about how changing your belay setup changes the force on the anchor so I explained as best I could. I still want to know if the belayer was a BUS method user...
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notapplicable
Feb 8, 2011, 4:02 PM
Post #35 of 151
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shoo wrote: wwalt822 wrote: In a frictionless world redirecting would double the force on the anchor. Belaying off the harness with a redirect through the anchor nearly doubles the force on the anchor except for the friction of the redirect biner. Belaying off the anchor with a redirect back through the anchor doubles the force minus the friction of the redirect biner and minus the friction of the belay device. Or another way of looking at this is you will have the weight of the climber plus the force of the brake hand on the anchor. OMG! It could DOUBLE an extremely small amount of force relative to anchor strength in a scenario so unrealistic as to by totally irrelevant all while making belaying massively more difficult?!?! I MUST WARN THE INTERNETS!!!!
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vegastradguy
Feb 8, 2011, 4:14 PM
Post #36 of 151
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wwalt822 wrote: shoo wrote: wwalt822 wrote: In a frictionless world redirecting would double the force on the anchor. Belaying off the harness with a redirect through the anchor nearly doubles the force on the anchor except for the friction of the redirect biner. Belaying off the anchor with a redirect back through the anchor doubles the force minus the friction of the redirect biner and minus the friction of the belay device. Or another way of looking at this is you will have the weight of the climber plus the force of the brake hand on the anchor. OMG! It could DOUBLE an extremely small amount of force relative to anchor strength in a scenario so unrealistic as to by totally irrelevant all while making belaying massively more difficult?!?! I MUST WARN THE INTERNETS!!!! Did I say there was a problem with doing it any of these ways? And the only unrealistic scenario is the frictionless one. Someone was confused about how changing your belay setup changes the force on the anchor so I explained as best I could. I still want to know if the belayer was a BUS method user... I would bet he was a pinch and slider, but thats conjecture at best given that he was lowering his partner when the accident occurred.
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justroberto
Feb 8, 2011, 4:17 PM
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j_ung wrote: healyje wrote: They most likely just brought the two rope strands together in front of them and gravity did the rest. From the sound of it both D and A were in over their heads and experience level for this incident to have occurred as it did. Agree. Of course, it's a guess, but I'm inclined to chalk this up almost entirely to the belayer being caught off guard by the weighted re-orientation of every part of the system away from what he's used to. The climber's poor choice to climb on is certainly also to blame. ^This. Your belayer doesn't seem to be trying to hide anything, but when people end up with ropeburns on their hands, it screams that they let go of the brake and grabbed the belayer climber end of the rope. When relatively inexperienced belayers get surprised by something unexpected, sometimes this is their first instinct. Is that Pilot? Because friends don't let friends climb there. I also lay some of the blame on their friends.
(This post was edited by justroberto on Feb 8, 2011, 4:43 PM)
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dugl33
Feb 8, 2011, 4:24 PM
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justroberto wrote: j_ung wrote: healyje wrote: They most likely just brought the two rope strands together in front of them and gravity did the rest. From the sound of it both D and A were in over their heads and experience level for this incident to have occurred as it did. Agree. Of course, it's a guess, but I'm inclined to chalk this up almost entirely to the belayer being caught off guard by the weighted re-orientation of every part of the system away from what he's used to. The climber's poor choice to climb on is certainly also to blame. ^This. Your belayer doesn't seem to be trying to hide anything, but when people end up with ropeburns on their hands, it screams that they let go of the brake and grabbed the belayer end of the rope. When relatively inexperienced belayers get surprised by something unexpected, sometimes this is their first instinct. Is that Pilot? Because friends don't let friends climb there. I also lay some of the blame on their friends. Uh, you mean climber side? If so, agreed!
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Rmsyll2
Feb 8, 2011, 4:24 PM
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"I do not know the usual kN for [belay loops]" My BD, I just found out, is 15 kN. Carabiners in-line are much more than that, half that cross or open.
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potreroed
Feb 8, 2011, 4:25 PM
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If the belayer had been using a gri gri and a re-direct this accident would prolly not have happened.
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shoo
Feb 8, 2011, 4:31 PM
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potreroed wrote: If the belayer had been using a gri gri and a re-direct this accident would prolly not have happened. Fixed.
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justroberto
Feb 8, 2011, 4:42 PM
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dugl33 wrote: justroberto wrote: j_ung wrote: healyje wrote: They most likely just brought the two rope strands together in front of them and gravity did the rest. From the sound of it both D and A were in over their heads and experience level for this incident to have occurred as it did. Agree. Of course, it's a guess, but I'm inclined to chalk this up almost entirely to the belayer being caught off guard by the weighted re-orientation of every part of the system away from what he's used to. The climber's poor choice to climb on is certainly also to blame. ^This. Your belayer doesn't seem to be trying to hide anything, but when people end up with ropeburns on their hands, it screams that they let go of the brake and grabbed the belayer end of the rope. When relatively inexperienced belayers get surprised by something unexpected, sometimes this is their first instinct. Is that Pilot? Because friends don't let friends climb there. I also lay some of the blame on their friends. Uh, you mean climber side? If so, agreed! Doh! That's what I meant.
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shockabuku
Feb 8, 2011, 4:43 PM
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The gear ratings and placements (apparently) aren't the contributing factors to the accident discussed here. They may or may not have been good placements, but nothing appears to have broken or pulled out. The error is (apparently) entirely attributable to the belayer doing something wrong. It's most likely that error was either (1) grabbing the climber's side of the rope or (2) not understanding how to orient the brake strand relative to the direction of pull.
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Rmsyll2
Feb 8, 2011, 4:47 PM
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"I think you are still confused." Therefore, this post -- and it may be getting worse, at least for me. What is "the BUS method"? The term "redirect" means to me having the system go beyond the belayer to an anchor, so that the person is only or primarily handling the friction method. The point of pulley advantage seems to be moving away from the belayer's efforts, which Jay raised earlier, and onto the anchor. If a change in direction, with a carabiner as a pulley wheel and possibly in a redirect belay, does increase force on the anchor, that confirms the advantage on the brake hand. And some are still saying they don't use anchors on top-belay anyway. A person standing or sitting on a rim won't be pulled off by a falling climber? Consensus is a foolish expectation with this forum. But I am heartened that only one reply misspelled "brake" as effectively its opposite. .
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wwalt822
Feb 8, 2011, 4:51 PM
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I'm going to guess he was BUS user. I agree with the others in that he was probably used to pulling the rope downward to brake. The BUS method instills the muscle memory of driving the rope downwards between your legs to brake which is useless when belaying off the harness from above I'm a palm up pinch and slide user (ZOMG my climber's gonna die!!!11exclamationone1121240!) and my reaction is always to lock my hand next to my hip. This will apply braking power whether belaying from below or belaying off my harness from above. EDIT: BUS method explained http://www.youtube.com/watch?v=2-a0FLqwPL8
(This post was edited by wwalt822 on Feb 8, 2011, 4:52 PM)
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shoo
Feb 8, 2011, 4:56 PM
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Rmsyll2 wrote: "I think you are still confused." Therefore, this post -- and it may be getting worse, at least for me. What is "the BUS method"? The term "redirect" means to me having the system go beyond the belayer to an anchor, so that the person is only or primarily handling the friction method. The point of pulley advantage seems to be moving away from the belayer's efforts, which Jay raised earlier, and onto the anchor. If a change in direction, with a carabiner as a pulley wheel and possibly in a redirect belay, does increase force on the anchor, that confirms the advantage on the brake hand. And some are still saying they don't use anchors on top-belay anyway. A person standing or sitting on a rim won't be pulled off by a falling climber? Consensus is a foolish expectation with this forum. But I am heartened that only one reply misspelled "brake" as effectively its opposite. . I am now slightly less convinced that this post is genuine, and now suspect elaborate troll. And if it not a troll, to the OP: you are severely misunderstanding what has been said here. Please do yourself a favor. Log off the internet and go hire a guide or convince and experienced and well qualified climber to teach you these things in person.
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wwalt822
Feb 8, 2011, 4:59 PM
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Rmsyll2 wrote: "I think you are still confused." Therefore, this post -- and it may be getting worse, at least for me. What is "the BUS method"? The term "redirect" means to me having the system go beyond the belayer to an anchor, so that the person is only or primarily handling the friction method. The point of pulley advantage seems to be moving away from the belayer's efforts, which Jay raised earlier, and onto the anchor. If a change in direction, with a carabiner as a pulley wheel and possibly in a redirect belay, does increase force on the anchor, that confirms the advantage on the brake hand. And some are still saying they don't use anchors on top-belay anyway. A person standing or sitting on a rim won't be pulled off by a falling climber? Consensus is a foolish expectation with this forum. But I am heartened that only one reply misspelled "brake" as effectively its opposite. . You seem to be very confused. A belay device is only a friction creator. Unless you were to make a complicated and useless z pulley setup of some kind on the brake strand only you do not get any mechanical advantage from a redirect. A redirect is exactly what it sounds like. It redirects the force coming out of the belay device through the anchor or some other piece of protection. The advantage of this is that the belayer can sit back in his harness and belay in pretty much the same way as if he were at the bottom of the cliff belaying a top roper. I suggest you read up on block and tackle physics. I don't know anyone that would belay or climb with belayer that was not anchored in unless it was very mellow terrain. I'm guessing when they say they dont use the anchor they mean that they don't belay directly off the anchor.
(This post was edited by wwalt822 on Feb 8, 2011, 5:03 PM)
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shockabuku
Feb 8, 2011, 5:00 PM
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What do you mean by "the friction method"?
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wwalt822
Feb 8, 2011, 5:00 PM
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shoo wrote: Rmsyll2 wrote: "I think you are still confused." Therefore, this post -- and it may be getting worse, at least for me. What is "the BUS method"? The term "redirect" means to me having the system go beyond the belayer to an anchor, so that the person is only or primarily handling the friction method. The point of pulley advantage seems to be moving away from the belayer's efforts, which Jay raised earlier, and onto the anchor. If a change in direction, with a carabiner as a pulley wheel and possibly in a redirect belay, does increase force on the anchor, that confirms the advantage on the brake hand. And some are still saying they don't use anchors on top-belay anyway. A person standing or sitting on a rim won't be pulled off by a falling climber? Consensus is a foolish expectation with this forum. But I am heartened that only one reply misspelled "brake" as effectively its opposite. . I am now slightly less convinced that this post is genuine, and now suspect elaborate troll. And if it not a troll, to the OP: you are severely misunderstanding what has been said here. Please do yourself a favor. Log off the internet and go hire a guide or convince and experienced and well qualified climber to teach you these things in person. Come on Rmsyll, admit you dropped your climber...
(This post was edited by wwalt822 on Feb 8, 2011, 5:11 PM)
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dugl33
Feb 8, 2011, 5:19 PM
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Rmsyll2 wrote: "I think you are still confused." Therefore, this post -- and it may be getting worse, at least for me. What is "the BUS method"? The term "redirect" means to me having the system go beyond the belayer to an anchor, so that the person is only or primarily handling the friction method. The point of pulley advantage seems to be moving away from the belayer's efforts, which Jay raised earlier, and onto the anchor. If a change in direction, with a carabiner as a pulley wheel and possibly in a redirect belay, does increase force on the anchor, that confirms the advantage on the brake hand. And some are still saying they don't use anchors on top-belay anyway. A person standing or sitting on a rim won't be pulled off by a falling climber? Consensus is a foolish expectation with this forum. But I am heartened that only one reply misspelled "brake" as effectively its opposite. . No! No it doesn't. Here, this may help. Note the difference between the first diagram and the second. The first diagram shows a change in direction with no mechanical advantage with regards to braking, the second one would create a 2:1 mechanical advantage with regards to raising. Consider your frame of reference.... consider loads on each component. Put 200 lbs on the left side of the pulley in the first diagram, you will have 200 lbs of load on the right side. The fact that the load on the pulley point of connection is now holding 400 lbs doesn't change the fact that you are still holding 200 lbs. http://www.southeastclimbing.com/faq/faq_pulley.htm
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