|
|
|
|
jt512
Mar 27, 2010, 10:11 PM
Post #251 of 360
(13389 views)
Shortcut
Registered: Apr 12, 2001
Posts: 21904
|
blueeyedclimber wrote: jt512 wrote: blueeyedclimber wrote: jt512 wrote: blueeyedclimber wrote: I use an atc guide and most of the time I belay of the anchor. If I have to give slack, it can be a little bit of a pain, and in this instance a tuber off your harness is DEFINITELY easier. You speak of these "instances" in which you "have to" give slack as if they are rare. But if you are giving a good belay, then every time your second steps down a foot to get a shake, to get a different angle on removing a piece, or to try a move a different way, you should be giving the second slack. Such little retreats are not rare; they're routine. And if you can't pay out slack to accommodate them as quickly as you can take up slack in response to a step upward, then you simply are giving a lousy belay. In reply to: For those who say different are FOS, but the benefits of an autoblock (for me) outweigh that. First of all, at this point in thread, after the counterarguments to these supposed benefits, given by rgold (as quoted by robdotcalm), by robdotcalm himself, by me, by zeke (below), and by others, it is no longer valid to simply assert the existence of these benefits. We've shot down every one that has been mentioned for routine cragging while belaying a single follower. Furthermore, the question shouldn't be whether the benefits (even if they are real) for the belayer outweigh the disadvantages for the second, but whether the benefits (if any) for the second outweigh the disadvantages for the second. You belay primarily for the benefit of the person you are belaying, not for yourself. Jay YAWN. Here we go again. I love how you like to assume what I am inferring. I have to give slack quite a bit, as you say. To state that it is easier when belaying off of your harness is true. But guess what, I can do it pretty fast off the anchor as well. Well, "pretty fast" is still to slow. If you can't let slack out as fast as you can take it in, the quality of the belay you are giving has been compromised, with essentially no compensating benefit. Jay If we're talking at the sport crag, then I agree with you. And once again, I am not sure if we are only talking cragging, because belaying a multipitch route, that may be a full rope length or where you can't see your second or traverses, or is 20 pitches up with night falling, etc, etc... has different considerations. I think it's ridiculous to say that you shouldn't use an autoblock (as long as you know how to use it), just like it's ridiculous to say you SHOULD use one. Josh
Josh, read the thread already. The need to move fast has already been established as one reason you might choose an autoblock, and no one is taking the position that you should never use one.
In reply to: Use what you want.
Or, to generalize, "do what you want." After all, it's not as if actions ever have consequences.
Jay
|
|
|
|
|
blueeyedclimber
Mar 27, 2010, 10:18 PM
Post #252 of 360
(13383 views)
Shortcut
Registered: Nov 19, 2002
Posts: 4602
|
jt512 wrote: blueeyedclimber wrote: jt512 wrote: blueeyedclimber wrote: jt512 wrote: blueeyedclimber wrote: I use an atc guide and most of the time I belay of the anchor. If I have to give slack, it can be a little bit of a pain, and in this instance a tuber off your harness is DEFINITELY easier. You speak of these "instances" in which you "have to" give slack as if they are rare. But if you are giving a good belay, then every time your second steps down a foot to get a shake, to get a different angle on removing a piece, or to try a move a different way, you should be giving the second slack. Such little retreats are not rare; they're routine. And if you can't pay out slack to accommodate them as quickly as you can take up slack in response to a step upward, then you simply are giving a lousy belay. In reply to: For those who say different are FOS, but the benefits of an autoblock (for me) outweigh that. First of all, at this point in thread, after the counterarguments to these supposed benefits, given by rgold (as quoted by robdotcalm), by robdotcalm himself, by me, by zeke (below), and by others, it is no longer valid to simply assert the existence of these benefits. We've shot down every one that has been mentioned for routine cragging while belaying a single follower. Furthermore, the question shouldn't be whether the benefits (even if they are real) for the belayer outweigh the disadvantages for the second, but whether the benefits (if any) for the second outweigh the disadvantages for the second. You belay primarily for the benefit of the person you are belaying, not for yourself. Jay YAWN. Here we go again. I love how you like to assume what I am inferring. I have to give slack quite a bit, as you say. To state that it is easier when belaying off of your harness is true. But guess what, I can do it pretty fast off the anchor as well. Well, "pretty fast" is still to slow. If you can't let slack out as fast as you can take it in, the quality of the belay you are giving has been compromised, with essentially no compensating benefit. Jay If we're talking at the sport crag, then I agree with you. And once again, I am not sure if we are only talking cragging, because belaying a multipitch route, that may be a full rope length or where you can't see your second or traverses, or is 20 pitches up with night falling, etc, etc... has different considerations. I think it's ridiculous to say that you shouldn't use an autoblock (as long as you know how to use it), just like it's ridiculous to say you SHOULD use one. Josh Josh, read the thread already. The need to move fast has already been established as one reason you might choose an autoblock, and no one is taking the position that you should never use one. In reply to: Use what you want. Or, to generalize, "do what you want." After all, it's not as if actions ever have consequences. Jay
Jay, I am not going to read the thread right now, maybe later. If I am arguing about something that is irrelevant in this thread, then I will stop. In my defense, you started arguing with me.
I actually agree with some of your points, as it pertains to cragging, but from my perspective it seemed you were arguing that autoblocks shouldn't be used. I don't agree with that. I also don't agree with people that says the SHOULD be used.
For you to take my comment "Use what you want", and turn it into "Or, to generalize, "do what you want." After all, it's not as if actions ever have consequences," is an ass thing to do. If that's what you think I meant, then WHATEVER!
Josh
|
|
|
|
|
Gmburns2000
Mar 27, 2010, 10:18 PM
Post #253 of 360
(13381 views)
Shortcut
Registered: Mar 6, 2007
Posts: 15266
|
jt512 wrote: blueeyedclimber wrote: I use an atc guide and most of the time I belay of the anchor. If I have to give slack, it can be a little bit of a pain, and in this instance a tuber off your harness is DEFINITELY easier. You speak of these "instances" in which you "have to" give slack as if they are rare. But if you are giving a good belay, then every time your second steps down a foot to get a shake, to get a different angle on removing a piece, or to try a move a different way, you should be giving the second slack. Such little retreats are not rare; they're routine. And if you can't pay out slack to accommodate them as quickly as you can take up slack in response to a step upward, then you simply are giving a lousy belay. In reply to: For those who say different are FOS, but the benefits of an autoblock (for me) outweigh that. First of all, at this point in thread, after the counterarguments to these supposed benefits, given by rgold (as quoted by robdotcalm), by robdotcalm himself, by me, by zeke (below), and by others, it is no longer valid to simply assert the existence of these benefits. We've shot down every one that has been mentioned for routine cragging while belaying a single follower. Furthermore, the question shouldn't be whether the benefits (even if they are real) for the belayer outweigh the disadvantages for the second, but whether the benefits (if any) for the second outweigh the disadvantages for the second. You belay primarily for the benefit of the person you are belaying, not for yourself. Jay
waaaaaaaaait a minute, when did this conversation become specifically about routine cragging? I know that's kinda what happened in the original accident (looooong forgotten in this thread, btw), but I haven't been getting the sense that everyone who likes using an autoblock-type device has been arguing the merits of using one at a regular cragging location.
I climb mostly multi-pitch routes with double ropes; I don't consider that routine cragging. I know that BEC and WW both typically climb in the same places I do, and I'm pretty sure they don't consider that routine cragging either (but, I won't entirely put words in their mouth, so if I'm wrong about that then sorry).
In any case, I was always under the impression this discussion was about the merits of a particular device, not about the merits of a particular device while cragging.
|
|
|
|
|
zeke_sf
Mar 27, 2010, 10:46 PM
Post #254 of 360
(13372 views)
Shortcut
Registered: Apr 28, 2006
Posts: 18730
|
wonderwoman wrote: Belaying off an anchor takes the force of the second's fall off your body and puts it on the anchor. That's one of the perks for using a gri gri or reverso / guide on multi pitch. Not to be done, of course, during a traverse where you should be belaying from your harness.
I don't get it [waits for somebody to "cleverly" snip this phrase out and say "yeah, we get that"], doesn't the anchor also take the force of an autoblock device directly attached to it?
I'll admit that I really don't know the physics of it, I just know it's generally accepted you probably don't want to autoblock or redirect on a marginal anchor. Most anchors I've constructed have been truck, entirely eliminating this concern. That's not bragging about my skillzzz, just a function of the major "trade route" type of climbing I do. The major lesson I see here is that belay choice is highly situational, and Jay (T512D) is right, autoblock really shouldn't be the defacto choice.
|
|
|
|
|
yokese
Mar 27, 2010, 10:56 PM
Post #255 of 360
(13369 views)
Shortcut
Registered: Jan 18, 2006
Posts: 672
|
jt512 wrote: So your argument is basically, it's newer, therefore, it's better.
Throughout this thread, you've been using the argument that people use the ATC guide just (or mostly) because is trendy, being "newer" and having the word "guide" on it. I know that you're well aware that the same principle under which the ATC Guide works has been used by many climbers for ages, with the Gigi plates, for reasons other than being "newer" or having the word "guide" on them.
Based on what you wrote in this thread, less knowledgeable climbers might be mislead into thinking that somehow the ATC guide or the reverso introduced a new (and inferior) way of belaying.
|
|
|
|
|
Gmburns2000
Mar 27, 2010, 11:14 PM
Post #256 of 360
(13362 views)
Shortcut
Registered: Mar 6, 2007
Posts: 15266
|
zeke_sf wrote: wonderwoman wrote: Belaying off an anchor takes the force of the second's fall off your body and puts it on the anchor. That's one of the perks for using a gri gri or reverso / guide on multi pitch. Not to be done, of course, during a traverse where you should be belaying from your harness. I don't get it [waits for somebody to "cleverly" snip this phrase out and say "yeah, we get that"], doesn't the anchor also take the force of an autoblock device directly attached to it? I'll admit that I really don't know the physics of it, I just know it's generally accepted you probably don't want to autoblock or redirect on a marginal anchor. Most anchors I've constructed have been truck, entirely eliminating this concern. That's not bragging about my skillzzz, just a function of the major "trade route" type of climbing I do. The major lesson I see here is that belay choice is highly situational, and Jay (T512D) is right, autoblock really shouldn't be the defacto choice.
I'm not getting the sense that is what he's saying. I'm getting the sense that he's saying they are an inferior device, which is different than "defacto."
I don't mean to split hairs here, but I don't get the sense that he's saying there is a situation for them. I think he's saying that even if one could use them there are much better alternatives.
|
|
|
|
|
redlude97
Mar 28, 2010, 12:54 AM
Post #257 of 360
(13340 views)
Shortcut
Registered: Aug 27, 2008
Posts: 990
|
Gmburns2000 wrote: zeke_sf wrote: wonderwoman wrote: Belaying off an anchor takes the force of the second's fall off your body and puts it on the anchor. That's one of the perks for using a gri gri or reverso / guide on multi pitch. Not to be done, of course, during a traverse where you should be belaying from your harness. I don't get it [waits for somebody to "cleverly" snip this phrase out and say "yeah, we get that"], doesn't the anchor also take the force of an autoblock device directly attached to it? I'll admit that I really don't know the physics of it, I just know it's generally accepted you probably don't want to autoblock or redirect on a marginal anchor. Most anchors I've constructed have been truck, entirely eliminating this concern. That's not bragging about my skillzzz, just a function of the major "trade route" type of climbing I do. The major lesson I see here is that belay choice is highly situational, and Jay (T512D) is right, autoblock really shouldn't be the defacto choice. I'm not getting the sense that is what he's saying. I'm getting the sense that he's saying they are an inferior device, which is different than "defacto." I don't mean to split hairs here, but I don't get the sense that he's saying there is a situation for them. I think he's saying that even if one could use them there are much better alternatives.
|
|
|
|
|
jt512
Mar 28, 2010, 1:04 AM
Post #258 of 360
(13334 views)
Shortcut
Registered: Apr 12, 2001
Posts: 21904
|
Gmburns2000 wrote: jt512 wrote: blueeyedclimber wrote: I use an atc guide and most of the time I belay of the anchor. If I have to give slack, it can be a little bit of a pain, and in this instance a tuber off your harness is DEFINITELY easier. You speak of these "instances" in which you "have to" give slack as if they are rare. But if you are giving a good belay, then every time your second steps down a foot to get a shake, to get a different angle on removing a piece, or to try a move a different way, you should be giving the second slack. Such little retreats are not rare; they're routine. And if you can't pay out slack to accommodate them as quickly as you can take up slack in response to a step upward, then you simply are giving a lousy belay. In reply to: For those who say different are FOS, but the benefits of an autoblock (for me) outweigh that. First of all, at this point in thread, after the counterarguments to these supposed benefits, given by rgold (as quoted by robdotcalm), by robdotcalm himself, by me, by zeke (below), and by others, it is no longer valid to simply assert the existence of these benefits. We've shot down every one that has been mentioned for routine cragging while belaying a single follower. Furthermore, the question shouldn't be whether the benefits (even if they are real) for the belayer outweigh the disadvantages for the second, but whether the benefits (if any) for the second outweigh the disadvantages for the second. You belay primarily for the benefit of the person you are belaying, not for yourself. Jay waaaaaaaaait a minute, when did this conversation become specifically about routine cragging?
*facepalm*
Please take a class in logic.
Jay
|
|
|
|
|
jt512
Mar 28, 2010, 1:06 AM
Post #259 of 360
(13332 views)
Shortcut
Registered: Apr 12, 2001
Posts: 21904
|
yokese wrote: jt512 wrote: So your argument is basically, it's newer, therefore, it's better. Throughout this thread, you've been using the argument that people use the ATC guide just (or mostly) because is trendy, being "newer" and having the word "guide" on it. I know that you're well aware that the same principle under which the ATC Guide works has been used by many climbers for ages, with the Gigi plates, for reasons other than being "newer" or having the word "guide" on them. Based on what you wrote in this thread, less knowledgeable climbers might be mislead into thinking that somehow the ATC guide or the reverso introduced a new (and inferior) way of belaying.
I don't why they would be misled into thinking that, or even why it is relevant to the discussion.
Jay
|
|
|
|
|
jt512
Mar 28, 2010, 1:09 AM
Post #260 of 360
(13328 views)
Shortcut
Registered: Apr 12, 2001
Posts: 21904
|
Gmburns2000 wrote: zeke_sf wrote: wonderwoman wrote: Belaying off an anchor takes the force of the second's fall off your body and puts it on the anchor. That's one of the perks for using a gri gri or reverso / guide on multi pitch. Not to be done, of course, during a traverse where you should be belaying from your harness. I don't get it [waits for somebody to "cleverly" snip this phrase out and say "yeah, we get that"], doesn't the anchor also take the force of an autoblock device directly attached to it? I'll admit that I really don't know the physics of it, I just know it's generally accepted you probably don't want to autoblock or redirect on a marginal anchor. Most anchors I've constructed have been truck, entirely eliminating this concern. That's not bragging about my skillzzz, just a function of the major "trade route" type of climbing I do. The major lesson I see here is that belay choice is highly situational, and Jay (T512D) is right, autoblock really shouldn't be the defacto choice. I'm not getting the sense that is what he's saying. I'm getting the sense that he's saying they are an inferior device, which is different than "defacto."
Then take a reading comprehension class along with your logic class.
And I think the term you guys are looking for is "default," not "de facto."
Jay
|
|
|
|
|
jt512
Mar 28, 2010, 1:27 AM
Post #261 of 360
(13320 views)
Shortcut
Registered: Apr 12, 2001
Posts: 21904
|
Gmburns2000 wrote: I climb mostly multi-pitch routes with double ropes; I don't consider that routine cragging.
Sorry to inform you, but that is indeed routine cragging.
How many blog entries did that realization just negate?
Jay
|
|
|
|
|
cracklover
Mar 28, 2010, 2:13 AM
Post #262 of 360
(13296 views)
Shortcut
Registered: Nov 14, 2002
Posts: 10162
|
jt512 wrote: Gmburns2000 wrote: I climb mostly multi-pitch routes with double ropes; I don't consider that routine cragging. Sorry to inform you, but that is indeed routine cragging. How many blog entries did that realization just negate? Jay
Not to derail the thread, but there does seem to be a disconnect here. Can we all agree that routine cragging is any rock or ice route at grade III or under?
GO
|
|
|
|
|
stagg54
Mar 28, 2010, 2:24 AM
Post #263 of 360
(13294 views)
Shortcut
Registered: Apr 28, 2005
Posts: 190
|
blueeyedclimber wrote: I agree Jay. I get a kick out of people who have read a self-rescue book, and all of a sudden their answer to everything is to just set up a haul. There are some very common and simple situations that would render a haul useless. Josh
Yes I have read a self-rescue book. Anyone who is serious about climbing should read one at some point. But I've actually done it as well. I've hauled my 150lb partner 15-20 feet several times and yes it does work. It's not easy, but not as bad as your making it out to be either. I've also hauled people out of crevasses on a few occassions.
Does it always work in every situation- obviously not. It's hard to haul someone through a piece of gear.
It's easy to sit back and throw insults, but what do you have to add to the conversation?
edited for my bad spelling
(This post was edited by stagg54 on Mar 28, 2010, 2:26 AM)
|
|
|
|
|
wonderwoman
Mar 28, 2010, 2:29 AM
Post #264 of 360
(13277 views)
Shortcut
Registered: Dec 14, 2002
Posts: 4275
|
zeke_sf wrote: wonderwoman wrote: Belaying off an anchor takes the force of the second's fall off your body and puts it on the anchor. That's one of the perks for using a gri gri or reverso / guide on multi pitch. Not to be done, of course, during a traverse where you should be belaying from your harness. I don't get it [waits for somebody to "cleverly" snip this phrase out and say "yeah, we get that"], doesn't the anchor also take the force of an autoblock device directly attached to it? I'll admit that I really don't know the physics of it, I just know it's generally accepted you probably don't want to autoblock or redirect on a marginal anchor. Most anchors I've constructed have been truck, entirely eliminating this concern. That's not bragging about my skillzzz, just a function of the major "trade route" type of climbing I do. The major lesson I see here is that belay choice is highly situational, and Jay (T512D) is right, autoblock really shouldn't be the defacto choice.
I agree that you should not belay directly off a marginal anchor. It's always a good idea to assess the situation & make a decision on how to set up your belay. Thinking outside of the box & not relying on a 'one size fits all' method certainly certainly helps out in a lot of climbing situations.
|
|
|
|
|
zeke_sf
Mar 28, 2010, 2:43 AM
Post #265 of 360
(13271 views)
Shortcut
Registered: Apr 28, 2006
Posts: 18730
|
wonderwoman wrote: zeke_sf wrote: wonderwoman wrote: Belaying off an anchor takes the force of the second's fall off your body and puts it on the anchor. That's one of the perks for using a gri gri or reverso / guide on multi pitch. Not to be done, of course, during a traverse where you should be belaying from your harness. I don't get it [waits for somebody to "cleverly" snip this phrase out and say "yeah, we get that"], doesn't the anchor also take the force of an autoblock device directly attached to it? I'll admit that I really don't know the physics of it, I just know it's generally accepted you probably don't want to autoblock or redirect on a marginal anchor. Most anchors I've constructed have been truck, entirely eliminating this concern. That's not bragging about my skillzzz, just a function of the major "trade route" type of climbing I do. The major lesson I see here is that belay choice is highly situational, and Jay (T512D) is right, autoblock really shouldn't be the defacto choice. I agree that you should not belay directly off a marginal anchor. It's always a good idea to assess the situation & make a decision on how to set up your belay. Thinking outside of the box & not relying on a 'one size fits all' method certainly certainly helps out in a lot of climbing situations.
Yes, I agree, I'm sure many here have employed a different belay type per each given pitch/partner/situation, but you didn't answer my first question. Does a redirect apply a significantly greater amount of force to an anchor than an autoblock setup? I would be interested to know and am assuredly too lazy to look up the answer myself.
|
|
|
|
|
ClimbClimb
Mar 28, 2010, 2:52 AM
Post #266 of 360
(13261 views)
Shortcut
Registered: Jan 5, 2009
Posts: 389
|
I come away from this discussion thinking the following:
There appears to be a significant risk associated with the ATC Guide used in a specific situation (autoblock + lowering) that can result in climber being dropped even by well-experienced climbers. Manufacturer's own instructions are somewhat unclear and may actually be wrong. In this accident, serious injury resulted (and even more serious injury was avoied through belayer's heroics) due to this flaw. Based on comments to manufacturer's instructions, it appears that at least one very similar incident occurred last year when someone was testing the device. It appears that many people currently using the dvice are likely to be unaware of the risk in that paritcular situation.
Actions would then be:
1. Make more people aware of this specific risk of dropping climber.
2. People make their own choices about the risk.
Fair summary?
|
|
|
|
|
jt512
Mar 28, 2010, 2:56 AM
Post #267 of 360
(13260 views)
Shortcut
Registered: Apr 12, 2001
Posts: 21904
|
zeke_sf wrote: Does a redirect apply a significantly greater amount of force to an anchor than an autoblock setup? I would be interested to know and am assuredly too lazy to look up the answer myself.
Yes, because there is a pulley effect with a redirect, but not (in principle) with an autoblock. If the tension on the climber's side of the rope is T, then the force on the autblock would be T, but the force on a redirect would be about 5T/3.
Edit: That assumes static belays, a reasonable assumption for the autoblock, but not so much for the redirect. Even if the belayer is anchored, there will still be some reduction of the impact force from deformation of the belayer's harness and body. Additionally, a regular ATC will slip at some reasonable load (~400 lbf?). I don't know at what force autoblock devices will slip, but I would guess that it would be higher.
Jay
(This post was edited by jt512 on Mar 28, 2010, 3:15 AM)
|
|
|
|
|
jt512
Mar 28, 2010, 3:03 AM
Post #268 of 360
(13257 views)
Shortcut
Registered: Apr 12, 2001
Posts: 21904
|
ClimbClimb wrote: I come away from this discussion thinking the following: There appears to be a significant risk associated with the ATC Guide used in a specific situation (autoblock + lowering) that can result in climber being dropped even by well-experienced climbers. Manufacturer's own instructions are somewhat unclear and may actually be wrong. In this accident, serious injury resulted (and even more serious injury was avoied through belayer's heroics) due to this flaw. Based on comments to manufacturer's instructions, it appears that at least one very similar incident occurred last year when someone was testing the device. It appears that many people currently using the dvice are likely to be unaware of the risk in that paritcular situation. Actions would then be: 1. Make more people aware of this specific risk of dropping climber. 2. People make their own choices about the risk. Fair summary?
Not really. It doesn't address the point that this risk can be entirely eliminated by not using the device (as an autoblock) in the first place, which is the most logical solution, since it is an inferior choice for most climbing situations.
Jay
|
|
|
|
|
wonderwoman
Mar 28, 2010, 3:12 AM
Post #269 of 360
(13253 views)
Shortcut
Registered: Dec 14, 2002
Posts: 4275
|
zeke_sf wrote: wonderwoman wrote: zeke_sf wrote: wonderwoman wrote: Belaying off an anchor takes the force of the second's fall off your body and puts it on the anchor. That's one of the perks for using a gri gri or reverso / guide on multi pitch. Not to be done, of course, during a traverse where you should be belaying from your harness. I don't get it [waits for somebody to "cleverly" snip this phrase out and say "yeah, we get that"], doesn't the anchor also take the force of an autoblock device directly attached to it? I'll admit that I really don't know the physics of it, I just know it's generally accepted you probably don't want to autoblock or redirect on a marginal anchor. Most anchors I've constructed have been truck, entirely eliminating this concern. That's not bragging about my skillzzz, just a function of the major "trade route" type of climbing I do. The major lesson I see here is that belay choice is highly situational, and Jay (T512D) is right, autoblock really shouldn't be the defacto choice. I agree that you should not belay directly off a marginal anchor. It's always a good idea to assess the situation & make a decision on how to set up your belay. Thinking outside of the box & not relying on a 'one size fits all' method certainly certainly helps out in a lot of climbing situations. Yes, I agree, I'm sure many here have employed a different belay type per each given pitch/partner/situation, but you didn't answer my first question. Does a redirect apply a significantly greater amount of force to an anchor than an autoblock setup? I would be interested to know and am assuredly too lazy to look up the answer myself.
I think it all depends. If your second falls while on redirect, the anchor takes the weight of your climber plus your weight of having to hold them at a stance. If there is a lot of friction in the system this might not make a difference at all. If you weigh a lot less than you second, it helps to belay off the anchor so you don't get pulled into the anchor.
|
|
|
|
|
zeke_sf
Mar 28, 2010, 3:14 AM
Post #270 of 360
(13251 views)
Shortcut
Registered: Apr 28, 2006
Posts: 18730
|
jt512 wrote: zeke_sf wrote: Does a redirect apply a significantly greater amount of force to an anchor than an autoblock setup? I would be interested to know and am assuredly too lazy to look up the answer myself. Yes, because there is a pulley effect with a redirect, but not (in principle) with an autoblock. If the tension on the climber's side of the rope is T, then the force on the autblock would be T, but the force on a redirect would be about 5T/3. Edit: That assumes static belays, a reasonable assumption for the autoblock, but not so much for the redirect. Even if the belayer is anchored, there will still be some reduction of the impact force from deformation of the belayer's harness and body. Additionally, a regular ATC will slip at some reasonable load (~400 lbf?), but I don't know at what force autoblock devices will slip. Jay
Thanks. So, for a 150 pound climber that's 250 pounds of tension, as opposed to the straight 150 Practically, that difference shouldn't be a big deal. But, then again, if it's a big deal, it's a BIG deal.
|
|
|
|
|
ClimbClimb
Mar 28, 2010, 3:20 AM
Post #271 of 360
(13243 views)
Shortcut
Registered: Jan 5, 2009
Posts: 389
|
jt512 wrote: Not really. It doesn't address the point that this risk can be entirely eliminated by not using the device (as an autoblock) in the first place, which is the most logical solution, since it is an inferior choice for most climbing situations.
FWIW, I agree with you -- it is disturbing that the device can causea fall when used in a way that it is only subtly different from the manufacturer's instructions, and it is disturbing that this fault was apparently noticed and reported to the manufacturer before this incident.
Clearly, others make a different judgment based on either risk/benefit analysis (they get more benfit from these than we can fathom) or feel that they were already well aware of the risk ("it's not news to me that it does that"). People may agree to disagree on that.
My summary was meant to be the minimum that everyone should be able to agree to in relation to this incident.
Really, it's shocking what happened here, if you take a step back. This shouldnt' be shrugged off as "noobs hurting themselves" -- seemingly experienced people using a popular device and having it go out of control on them.
|
|
|
|
|
blueeyedclimber
Mar 28, 2010, 3:37 AM
Post #272 of 360
(13225 views)
Shortcut
Registered: Nov 19, 2002
Posts: 4602
|
stagg54 wrote: blueeyedclimber wrote: I agree Jay. I get a kick out of people who have read a self-rescue book, and all of a sudden their answer to everything is to just set up a haul. There are some very common and simple situations that would render a haul useless. Josh Yes I have read a self-rescue book. Anyone who is serious about climbing should read one at some point. But I've actually done it as well. I've hauled my 150lb partner 15-20 feet several times and yes it does work. It's not easy, but not as bad as your making it out to be either. I've also hauled people out of crevasses on a few occassions. Does it always work in every situation- obviously not. It's hard to haul someone through a piece of gear. It's easy to sit back and throw insults, but what do you have to add to the conversation? edited for my bad spelling
It wasn't meant to be an insult. A lot of climbers (myself included) when first learning and applying self-rescue techniques mistakenly think that using a haul will be easy or work in every situation. I wasn't talking about pulling someone through gear, but about too much friction in the system to make a haul ineffective at best. The most effective one I have used, is the 2:1 assisted (I think that's what it's called).
You also need to stop pushing your partners into crevasses 
Josh
|
|
|
|
|
jt512
Mar 28, 2010, 3:38 AM
Post #273 of 360
(13223 views)
Shortcut
Registered: Apr 12, 2001
Posts: 21904
|
ClimbClimb wrote: jt512 wrote: Not really. It doesn't address the point that this risk can be entirely eliminated by not using the device (as an autoblock) in the first place, which is the most logical solution, since it is an inferior choice for most climbing situations. FWIW, I agree with you -- it is disturbing that the device can causea fall when used in a way that it is only subtly different from the manufacturer's instructions, and it is disturbing that this fault was apparently noticed and reported to the manufacturer before this incident. Clearly, others make a different judgment based on either risk/benefit analysis (they get more benfit from these than we can fathom) or feel that they were already well aware of the risk ("it's not news to me that it does that"). People may agree to disagree on that. My summary was meant to be the minimum that everyone should be able to agree to in relation to this incident. Really, it's shocking what happened here, if you take a step back. This shouldnt' be shrugged off as "noobs hurting themselves" -- seemingly experienced people using a popular device and having it go out of control on them.
I don't think I made myself clear. The reason that autoblocks are an inferior choice for most climbing situations—at least the reason I was referring to—is that they provide an inferior belay to the second. Unless there is some compelling, overriding reason, putting a competent climber on an autoblock is selfish, disrespectful, paternalistic, and condescending. A competent second who wants to free climb the pitch is entitled to the best belay you can give him, not one in which your ability to sense his movements through tactile feedback from the rope is impaired, and your ability to let out slack, should he want to downclimb even a foot, is almost nonexistent.
Jay
|
|
|
|
|
jt512
Mar 28, 2010, 3:46 AM
Post #274 of 360
(13219 views)
Shortcut
Registered: Apr 12, 2001
Posts: 21904
|
zeke_sf wrote: jt512 wrote: zeke_sf wrote: Does a redirect apply a significantly greater amount of force to an anchor than an autoblock setup? I would be interested to know and am assuredly too lazy to look up the answer myself. Yes, because there is a pulley effect with a redirect, but not (in principle) with an autoblock. If the tension on the climber's side of the rope is T, then the force on the autblock would be T, but the force on a redirect would be about 5T/3. Edit: That assumes static belays, a reasonable assumption for the autoblock, but not so much for the redirect. Even if the belayer is anchored, there will still be some reduction of the impact force from deformation of the belayer's harness and body. Additionally, a regular ATC will slip at some reasonable load (~400 lbf?), but I don't know at what force autoblock devices will slip. Jay Thanks. So, for a 150 pound climber that's 250 pounds of tension, as opposed to the straight 150 Practically, that difference shouldn't be a big deal. But, then again, if it's a big deal, it's a BIG deal.
You have to at least double both those numbers. If a 150-lb climber on top rope, with no tension in the rope and no slack, "falls," then the fall is a factor-0 fall; and the maximum impact force on his side of the rope will be twice his weight, resulting in forces of 300 and 500 lb, respectively, for an autoblock and a redirect. That's the minimum. If there is any slack in the rope, then the fall will be greater than factor 0, and the impact forces higher.
Jay
|
|
|
|
|
zeke_sf
Mar 28, 2010, 4:02 AM
Post #275 of 360
(13210 views)
Shortcut
Registered: Apr 28, 2006
Posts: 18730
|
jt512 wrote: zeke_sf wrote: jt512 wrote: zeke_sf wrote: Does a redirect apply a significantly greater amount of force to an anchor than an autoblock setup? I would be interested to know and am assuredly too lazy to look up the answer myself. Yes, because there is a pulley effect with a redirect, but not (in principle) with an autoblock. If the tension on the climber's side of the rope is T, then the force on the autblock would be T, but the force on a redirect would be about 5T/3. Edit: That assumes static belays, a reasonable assumption for the autoblock, but not so much for the redirect. Even if the belayer is anchored, there will still be some reduction of the impact force from deformation of the belayer's harness and body. Additionally, a regular ATC will slip at some reasonable load (~400 lbf?), but I don't know at what force autoblock devices will slip. Jay Thanks. So, for a 150 pound climber that's 250 pounds of tension, as opposed to the straight 150 Practically, that difference shouldn't be a big deal. But, then again, if it's a big deal, it's a BIG deal. You have to at least double both those numbers. If a 150-lb climber on top rope, with no tension in the rope and no slack, "falls," then the fall is a factor-0 fall; and the maximum impact force on his side of the rope will be twice his weight, resulting in forces of 300 and 500 lb, respectively, for an autoblock and a redirect. That's the minimum. If there is any slack in the rope, then the fall will be greater than factor 0, and the impact forces higher. Jay
Oh. I just assumed T was equal to the weight of the climber. Still, how many anchors have been pulled out by the force of a redirect? I imagine most anchor failures are because of lead falls. 'Course, it wouldn't be the first time I was mistaken in this discussion.
|
|
|
|
|
|
|
|
|
