Soft catch vs. hard catch
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20 kN wrote: You and Jeff are right, but there is (at least) one scenario where adding slack gives a soft catch. Picture the leader on a vertical or overhanging climb just above a bolt/piece such that there's only about 2 feet of rope between his knot and the draw. If you take out all/most of the slack, (assuming you're close to the weight of the climber) you'll slam them into the wall if they fall; a.k.a. short-roping them. I make sure that there's enough slack that the rope comes tight about 5-6' below the bolt, then allow myself to be pulled forward, step up, etc. for a soft catch, since I usually outweigh my leader. The loop might be longer if the bolt is just above a roof, so they don't slam their face into the rock when their feet go under it. So I have a "sport loop" out but it disappears as the leader gets higher above the bolt. I learned a phrase, "Give 'em a smile, not a mile" to describe how much slack to have out, and I think it's a good mnemonic. When you see 10' feet of slack lying on the ground... that's just stupid. |
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Patrik wrote: Overhanging doesn't mean a huge roof coming out it just means the wall is not straight vertical and I have only spent a day at jtree but everything I climbed there wasn't that hard but had overhanging sections on it. Not a giant roof sticking out but still small bulges coming out. Most major climbing areas in NC are all overhanging... pilot mountain, moore's wall, table rock (linville gorge), laurel's knob, etc. The only thing in NC I have been that doesn't have a large amount of some kinda overhang would be stone mountain. Alot of the areas you mention I have not been but alot of the pictures from there have overhangs in them. I am starting to think maybe you think an overhang is a completely upside down section of climbing. An overhang can be really small. Take this photo very small overhang but it is still overhanging and not "5.12" only 5.8, second photo only 5.7, third 5.8 entire thing is overhanging. |
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I'm rephrasing/reiterating my question upthread, because "ask your climber" only works if they actually understand light/heavy dynamics. I know experienced climbers who do not, simply because it just isn't something they run into much. This is my reality, so I'm the one who needs to know, to keep my climbers safe. For those of you who advocate a soft catch for the sake of the gear, wouldn't it be best to deliver that catch actively, by jumping just ahead of, or as, the rope comes taut? Rather than a passive soft catch when the climbers weight pulls you up, but has already put the full hit on the top piece. It seems to me, without the preemptive hop, only the climber gets the soft catch, not the gear. I'm asking as I'm the light belayer, and have direct experience with a ripped gear fall. Should I be prepared to give a soft catch even for the heavier climbers? Obviously taking everything else in consideration too. Thanks! Helen |
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Old lady H wrote: Many have tried, few succeeded. It's almost impossible to time your jump, and if you jump too soon, you make it worse. If you're anchored, well, there's not much you can do but perhaps let some rope slip through your device. But in trad climbing, you often just want to stop them ASAP. It Depends(tm). Use your best judgement. But if you're sport climbing, one thing you can do is squat if you know the fall is coming. This delays the weight of your legs coming onto the rope. Try it, it works. Alternatively, take an extra step away from the wall and allow yourself to be pulled forward. Be ready to get your feet in front of you!
Ripped gear is, and should be, very uncommon. Getting good gear is not the belayer's responsibility. As a light belayer there's not much you need, or should, do to soften the catch. Just protect yourself so you don't lose control of the belay. |
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The whole subject is a bottomless morass of poorly-understood phenomena, unacknowledged assumptions, physics confusion, and unjustifiable finger-pointing. By and large, the "soft catch" concept isn't even well-defined, as it confuses maximum rope tension and wall-impact velocities from pendulums. Soft catch strategies can increase one of these measures while decreasing the other. The videos are a welcome and among the first publicly-available steps in sorting some of this out, but they have their own problems in terms of indirect measurements and repeatability of results and of course can't come anywhere near addressing the myriad conditions that obtain in real situations. Meanwhile, the modern desire for simplistic answers to highly complex problems, perhaps conditioned by technology that falsely suggests such solutions are possible, has given rise to a new genre of blame-shifting, in which a belayer who has failed to provide a "soft catch" is the "cause" of a wall-impact injury sustained by a falling leader, as if the party ever returned to the site with exactly the same gear and all variables on-the-nose identical and re-did the fall to see if a "soft catch" (which version please) would have made any difference. By all means strive for belay strategies that will minimize the chance of injury to the leader, recognizing that some of these strategies require split-second decisions balancing competing demands about a very complex situation, and depend on actions that are effective only within very narrow time constraints. And sure, belayers have to have some real competence and on top of that be able to pay attention for a moderately sustained time period, and as neither of these qualities can be assumed, some belaying is surely worthy of condemnation. Having grasped all of this, understand that when you go climbing, you might get hurt, and much as we would like to pretend we are in control by blaming someone for a bad outcome, the reality is that the only real blame is that you made a decision to go climbing. By and large, you broke your ankles because you went climbing and took a fall, not because your belayer mis-timed a jump that might not have made any difference anyway. |
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Thank you, sirs! I'm not at high alert for every moment of every climb, no one is, but I am looking ahead for possible problems. I know everyone cares, as a belayer, but I do think having started with my own son on the sharp end ramped that up. Now, that's the default setting. Besides, it's more fun, anyway, and crucial if they really want to work something hard. Then, it's a real partnership! Best, Helen |
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rgold wrote: I think this is the major improvement in this video from previous videos I've seen on soft catches from these vloggers, which shows they've learned a lot. Now they're measuring impact velocity, which is something actually relevant to injuries, instead of the vague "softness" they were talking about in previous videos. Definitely they are not controlling a lot of relevant factors, but at least now they're collecting data I care about. I'm generally cynical about attempts at science driven by publicity, but maybe this particular morass isn't bottomless. Ultimately, when catching a fall, my two priorities, in order, are 1) avoiding ground/ledge/sharp-edge falls, 2) lowering wall impact velocity. Getting any meaningful control over those two potentials is complicated enough that I don't think it makes much sense to even consider other priorities, as you're not likely to be able to control outcomes of other factors within the reaction time constraints you have. Whether someone hits the ground/ledge/sharp-edge is fairly binary, so I think wall impact velocity is the most interesting data to collect. |
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And if you give the struggling weakling that keeps falling off where any normal Frenchperson would be no-hands resting and firing up another Gouloise a "soft" catch they moan like shit because it´s hard to get back up to the bolt again. |
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Jim Titt wrote: |
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Old lady H wrote: Regarding a dynamic belay to avoid ripping gear (as opposed to the different strategy of a "soft catch" keeping a climber from being slammed into the wall): "The full hit on the rope" (and the maximum force on the gear and climber) actually occurs near the end of the fall (when the rope has stretched the most), not at the start. Play with a rubberband and you'll see this. A non-stretched rubberband has no "force stored in it". Once you start to stretch a little, you get a gentle force. Stretch more and the force increases. A climbing rope is basically a big rubberband. So for a hard catch, the force on the top piece of gear (and climber) is increasing from 0 to its maximum value when the climber "bottoms out". The goal of a true dynamic belay is to reduce this peak force near the end of the fall. This can be done in two different ways: 1) The belayer can ADD some force early in the fall (by squatting, "taking", or backing away (but don't do this if there's risk of zippering!) from the wall) and "giving" at the end. This method can keep the total fall distance the same and (theoretically!) reduce the peak force by 50%. 2) If you skip the "initial adding of force" in 1) and instead add some extra fall distance at the end of the fall, you can "spread out" the fall breaking power over longer time (and risking the climber hitting a ledge). The reduction of peak force in this case depends on how much extra distance you add to the fall, but in practical cases I would think (as rgold mentioned, there are no real hard numbers available) you'll get a lot less than 50% force reduction. Maybe 10-20%? OLH: When you caught that fall when a piece popped, did you notice how incredibly fast the fall was? A fraction of a second, right? So, imagine to give very precise addition and subtraction of force through your belaying during this fraction of a second. A gut feeling: somewhat unlikely to happen. Especially if you intend to jump and let timing/gravity control when your body weight is going up vs going down. In worst case, your body has reached its peak height and is on the way DOWN at the same time as the climber "bottoms out" and you have ADDED to the peak force of the fall. Now, as for the "soft catch" (often discussed a lot in sport climbing) to keep a climber from slamming into the wall, the timing is actually not that critical. This is why the "sport loop" mentioned above mostly works just fine. Yes, as Achey mentioned, it really gives a larger peak force at the climber tie-in point (and the gear) but it mostly (hopefully!) keeps the climber away from the (overhanging!) wall, which is the main intent. Adding a little jump to the mix, just doesn't really hurt. But in this case, timing is not that critical. This is why most people will be reasonably successful in giving a "soft catch" in a sport environment (keeping the climber away from the wall), but trying to give a true dynamic belay to reduce maximum peak force is a lot more difficult task. Have you also noticed that it is the "sport crowd" that is highly enthusiastic about the "soft catch", but they also mostly encourage the use of gri-gri? This is one of the few cases where real measurements have been done and it is proven time and again that an ATC is resulting in a more dynamic belay than a gri-gri. Sport climbers are not really looking for a dynamic belay (to reduce the force on a 26kN bolt), they need a soft catch to not slam into the wall. These two are different. One is a lot easier than the other. So, if you are really concerned about trying to not rip gear, BUY A FRIGGIN' SCREAMER (or two) AND LET THE LEADER DECIDE WHICH PIECES OF GEAR ARE QUESTIONABLE! Don't put blame on the belayer for ripped pieces of gear. Don't insinuate that "maybe" the gear would have held with a dynamic belay. It is more appropriate to say: "Well, maybe that piece would not have ripped if the leader had put a screamer on it". |
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I thought the effectiveness of screamers had been debunked? |
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ViperScale wrote: Strong evidence that overhangs are photogenic. Not such strong evidence that these areas are mostly overhangs. Most of this route is vertical or slab. There six pictures of this route in the MP slideshow on the route's page, all six of them are pictures of this section of the third pitch. There are no pictures of any of the slabs or ledges in the first two pitches. It's Shockley's Ceiling, a 5.6 **** Gunks classic, so lots of people have climbed it and can verify that this route is mostly not overhung. |
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Mark E Dixon wrote: Link? |
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There's this whole thread- https://www.mountainproject.com/forum/topic/105947850/do-screamers-work?page=2 My bottom line, if Jim Titt thinks they are useless, that's good enough for me. |
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Patrik wrote: This is complete rubbish. The peak force on the gear occurs just after the peak impact on the belayer so very roughly a third of the fall distance after the rope starts coming tight. The peak force on the belayer occurs before the peak force on the faller and the peak force on the gear is at the point where these two forces combined are highest, delaying the peak on the belayer (by jumping at the wrong time or adding a screamer) can move the two peaks nearer together and thus increase the force on the top piece. |
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Mark E Dixon wrote: I too generally respect Jim's opinions, but it's a bit unclear from that thread if Jim actually thinks screamers are useless. Luckily the man is here, perhaps you can clarify, Jim? If my understanding of the physics is correct, the tearing screamer does dissipate energy. However, the screamer also allows the falling climber to build up more kinetic energy as they fall farther. This extra kinetic energy enters the rest of the system once the screamer has fully activated. Additionally, higher fall forces can cause the tearing of the stitching to dissippate less energy. If the extra distance fallen is long enough and the fall force high enough, the kinetic energy of the further fall will be greater than the energy dissipated by the screamer, resulting in higher forces on the rest of the system. The engineering conclusion I'd draw from this is that if real-world falls are seeing an increase in force from using a screamer, screamers should be made with stronger stitching that dissipates more force over shorter distance as it tears. Additionally, it would be ideal for the screamer to be long enough that real-world falls can't fully activate the screamer. The climbing-related conclusions I'd draw from this are to only use a screamer if there's a short (but difficult) distance to the next piece. But I definitely don't think I've fully modeled this whole situation in my head so there might be things I'm missing. |
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Patrik wrote:
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Mark E Dixon wrote: Well, I can see that an industrial application company ( yatesgear.com/climbing/scre…) might try to "extend the truth" a little bit and sell gear that's really intended for "via ferrata" style work applications as being somewhat related to lead climbing. |
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Jim Titt wrote: So, best practice for a lighter belayer with a climber on gear, is to just lock off and wait for the ride? This assumes no ledge, ground fall, pendulum, anything else but just a clean fall. All those other scenarios have other considerations, and I would hopefully anticipate those involving terrain, and be prepared with a plan. That's what I aim for, anyway. Yeah, yeah, the climber is responsible for their climb, but I'm still going to cover their ass if I can manage it, no matter why the shit happened. Sheesh. And, yes, it was fast, but a long fall, and I did have "time" to think a few thoughts. Mainly, noticing the rope twang when the gear went, and wondering why I was still going up and the climber still going down (not realizing yet a piece had popped). Thanks, all, much appreciated! Best, Helen |
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Patrik wrote: Even more than 50% considering that force grows faster-than-linearly with elongation for real ropes. But that's a static model (no motion). In a fall, real ropes absorb some energy through internal friction, which makes them somewhat more efficient to begin with (i.e. real ropes have a smaller length_of_fall * peak_force product than you would expect with a frictionless spring). Anyway, exploiting this with human reflexes is probably a dream. The real answer here is crouching/jumping belay robots. |