Falling on Multipitch with Light Belayer
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Michael Deller wrote:Another video, this one by Black Diamond showing different uses of their ATC Guide. Starting at about 1:24 in, they cover belaying your second off of an anchor. I prefer to do this when possible. vimeo.com/22320202Umm. Not relevant here. The discussion is about belaying the leader. |
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If you really want the soft catch and your belayer doesn't mind catching some air have her extend her tie in point a few extra feet below the anchor by using the rope and a clove. Three feet below the anchor gives her six feet of travel. |
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Great CMG video ! Thanks for posting this |
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There was a recent article in the german journal of mountain risk management that showed fixed point belays may have significantly higher forces on the last piece than a "normal" belay for moderate factor falls |
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bearbreeder wrote:There was a recent article in the german journal of mountain risk management that showed fixed point belays may have significantly higher forces on the last piece than a "normal" belay for moderate factor falls This may be a concern on less than ideal gear Ill post up the article once im back from climbing and on a real computah ;)It makes sense that this is the case. No force is being transferred to the belayer. The rope is already taking as much force as it can, and the remaining energy needs to be displaced somewhere. |
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bearbreeder wrote:http://www.bergundsteigen.at/file.php/archiv/2012/3/36-41%20%28steinzeitmethode%20fixpunktsicherung%29.pdf ;)Hi, my German wasn't up to the task. Any chance of telling us what the three cases are. Thanks! (Is it munter fixed to anchor, munter fixed to belayer, tube device fixed to belayer?) |
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The three arrangements are illustrated in the figure on the page previous to the one with the bar charts. I quickly scanned the article, but could not find what the movable mass is. I guess it's 80 kg. The arrangement on the right uses an artificial hand to provide controllable braking force. I could not find the value for that force either, but typical values would be less than 400 N. |
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David Coley wrote: Hi, my German wasn't up to the task. Any chance of telling us what the three cases are. Thanks! (Is it munter fixed to anchor, munter fixed to belayer, tube device fixed to belayer?)my understanding is that they tested - fixed rope to a fixed point - fixed rope to a moveable mass - tuber with artificial hand to a moveable mass in reality if you are muntering off a fixed point you would have some slippage of course the basic premise is that the counterweight of the belayer reduces the forces on the top piece in certain circumstances there are cases when it may not matter however ... such as when there is a lot of friction in the system anyways ... and they point this out IMO the basic take way is that if you have a clean rope run and a fall on gear, a fixed point belay may well increase the forces on the top piece youre basically depending mostly on the stretch of the rope and the slippage of the munter/tube on a fixed point to reduce the impact force ... there is no moving mass to absorb the impact of course if you weight double your belayer, this might be a good thing ... of if your belayer weights double you do, they may as well be a fixed point anyways this is somewhat similar to the BEAL propaganda about the stretch of the rope making more of a difference than the actual belay type in high friction situations (roofs, wandering moderate climbs) from the 2006 BMC technical conference thebmc.co.uk/Download.aspx?…; now the more interesting question is ... does it make sense of fixed point belays to use a stretchy low impact rope (beal, tendon, some bluewaters, etc) if you are leading on gear ... how about one of those > 9 KN impact force maxims ... hmmmmmm the other thing to note for belayers getting pulled up is that a stretchy low impact rope and tube device (rather than a grigri) has less force on the belayer as well as the climber, resulting in less "pull up"" ... of course the downside is that you fall further due to rope stretch, and theres slippage (hope you dont get dropped) ... there aint no free lunch !!!! ;) |
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I personally do not like using a gri gri on multipitch climbs. I have been sucked into the anchor and the cam opened on the gri gri by the wall or a biner. Not sure exactly what, but it opened up the gri gri and my climber fell a lot further than he should have and bruised an ankle. |
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jeff lebowski wrote:Universal rule in climbing: f$&k the secondThat's actually awesome |
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scottso wrote:I personally do not like using a gri gri on multipitch climbs. I have been sucked into the anchor and the cam opened on the gri gri by the wall or a biner. Not sure exactly what, but it opened up the gri gri and my climber fell a lot further than he should have and bruised an ankle.That is something I've always been concerned about, so it is interesting to know I wasn't just worrying about something that doesn't ever happen. My concern has always been the cam of the grigri meeting the krab of the jesus piece. If the jesus piece is part of the anchor I tend to unclip it once the leader has a few good pieces in so this is less likely to happen. |
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This has been addressed by other posters, but in case you want another explanation (with loads of other valuable information): |