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rockreaver
Jul 17, 2009, 5:50 PM
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Question: How much force will this generate and will this equipment handle it safely? Also is this the way the equipment was designed to be used? }--The equipment (PAS) made from 2 blue water titan loop chains (18Kn) and 2 Petzl Attache HMS Screwgate Carabiner (23Kn) and Metolius super safe harness.--{ I weigh 175 pounds if I were laying on a ledge and I fell 3 feet and fully weighted and stopped on the above loop chains and carabiners clipped onto Metolius rap-hangers would the system hold? Is there a risk of the carabiners shattering? Here is what's making me ask this: The other day I was watching some top-ropers (two teenage girls) hike up to the canyon rim to rig their rope from the top instead of lead climbing up and rigging the top-rope that way. I saw the dumbest thing I've ever seen. One of them slid out over the edge to rig the sling/anchor while the other held her feet (no I'm not kidding). I thought to myself that they are asking for death. I reasoned that if they had a PAS or two they could have done it more safely but then I caught myself. How? If they used a PAS or two they are still rolling the dice. The anchors were down way over the edge. If they used a PAS (a static system) while down-climbing from the ledge and they slip they are going to static-load the system and maybe shatter the carabiner and take a fall. So I ruled the PAS option out. (Am I right here?) After climbing I hiked up to see what they had to work with. There was nothing. They couldn't have tied into anything to rap down. It was flat. They could have rigged an anchor with 3 cams or stoppers in a low wall about 20 feet back from the edge but that assumes they had cams/stoppers and the rest of the gear to do that and rap off of. (Is this a safe approach if you don't lead-climb it? You could set 3 stoppers and rig a bomber anchor I think but is that stupid to do?) It stumped me and I was hoping to find a guide that could explain a safe way to do it. If you try to go over the edge and down climb down below the bolts to rig the rope you run the risk of falling and shattering your biners because a PAS isn't dynamic. There is no give in the system at all. At best all I can come up with is putting a screamer/load limiter on at the end of the PAS to try and reduce the fall factor. (But honestly I decided you either lead-climb it or walk away right?) Do you have suggestions for this situation? How would you do this safely aside from climbing lead from the bottom up which admittedly is much safer than trying to climb down the edge or have someone hold your ankles.
(This post was edited by rockreaver on Jul 17, 2009, 5:55 PM)
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Carnage
Jul 17, 2009, 6:00 PM
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sounds like the safest way to do it is to just lead it. in terms of the fall forces and such, im pretty sure a fall factor 2 fall on static ropes (which are more dynamic than webbing and such) generate around 17kN of force. This comes from the petzl fall simulator that they used to have up on their site (i cant find it anymore) so i wouldnt be surprised if you broke some of that gear from such a fall. if you really wanted to get into it, look into some of the gear they use for via ferras. they are made to deal with high FF falls.
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trenchdigger
Jul 17, 2009, 6:25 PM
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Carnage wrote: sounds like the safest way to do it is to just lead it. in terms of the fall forces and such, im pretty sure a fall factor 2 fall on static ropes (which are more dynamic than webbing and such) generate around 17kN of force. This comes from the petzl fall simulator that they used to have up on their site (i cant find it anymore) so i wouldnt be surprised if you broke some of that gear from such a fall. if you really wanted to get into it, look into some of the gear they use for via ferras. they are made to deal with high FF falls. Impact forces in shorter falls with a human as the load are significantly reduced by the softness and flexibilty of your body and limbs. The "whiplash" you get absorbs a good amount of the energy involved. As the fall gets longer (assuming the same fall factor) and amount of energy increases, your body's ability to dissipate some of that energy does not so the impact force will increase. The Petzl fall calculator fails to consider this variable, assuming a solid, inflexible mass and therefore will be less accurate for shorter falls with a human body as the falling body. The fact remains that even though a short, high FF fall on static line/webbing may not generate loads large enough to break gear, it's going to hurt like a MOFO!
(This post was edited by trenchdigger on Jul 17, 2009, 6:26 PM)
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Carnage
Jul 17, 2009, 6:32 PM
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trenchdigger wrote: Carnage wrote: sounds like the safest way to do it is to just lead it. in terms of the fall forces and such, im pretty sure a fall factor 2 fall on static ropes (which are more dynamic than webbing and such) generate around 17kN of force. This comes from the petzl fall simulator that they used to have up on their site (i cant find it anymore) so i wouldnt be surprised if you broke some of that gear from such a fall. if you really wanted to get into it, look into some of the gear they use for via ferras. they are made to deal with high FF falls. Impact forces in shorter falls with a human as the load are significantly reduced by the softness and flexibilty of your body and limbs. The "whiplash" you get absorbs a good amount of the energy involved. As the fall gets longer (assuming the same fall factor) and amount of energy increases, your body's ability to dissipate some of that energy does not so the impact force will increase. The Petzl fall calculator fails to consider this variable, assuming a solid, inflexible mass and therefore will be less accurate for shorter falls with a human body as the falling body. The fact remains that even though a short, high FF fall on static line/webbing may not generate loads large enough to break gear, it's going to hurt like a MOFO! was i not clear that when i said gear, i mean junk in your pants?
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gitarooman
Jul 17, 2009, 6:35 PM
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I dont think that the short distance that you would fall on a PAS would create anywhere near the force needed to 'shatter' a carabiner. In fact, I think that the carabiner would be one of the strongest parts of that system. Either way, a fall onto something static would probably teach you a lesson about falling on static things. Personally in that situation (having only your description to go by) I would have my partner put me on belay at the top (standing well back from the edge) and then work my way out there with my PAS to anchor in once I was at the chains. Better if there was something to get behind though. Again, not having seen the area, that would be my suggestion. EDIT: If there was a place to get gear in, yeah, making an anchor would be great.
(This post was edited by gitarooman on Jul 17, 2009, 6:38 PM)
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rockreaver
Jul 17, 2009, 6:39 PM
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trenchdigger wrote: The fact remains that even though a short, high FF fall on static line/webbing may not generate loads large enough to break gear, it's going to hurt like a MOFO! I couldn't agree more. Were I the girls I'd either build an anchor and rap down or I'd just walk away. I really don't think a TR 5.9 climb is worth dying over.
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trenchdigger
Jul 17, 2009, 6:39 PM
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Carnage wrote: was i not clear that when i said gear, i mean junk in your pants? Right! My bad...
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rockreaver
Jul 17, 2009, 6:41 PM
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gitarooman wrote: Personally in that situation (having only your description to go by) I would have my partner put me on belay at the top (standing well back from the edge) and then work my way out there with my PAS to anchor in once I was at the chains. Better if there was something to get behind though. Again, not having seen the area, that would be my suggestion. EDIT: If there was a place to get gear in, yeah, making an anchor would be great. Good idea. In fact great information. With the belay and the PAS backup that should be a fairly safe negotiation. I could have downclimbed it (I felt.) but I wanted more protection than I felt I could get without building an anchor.
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karcand
Jul 17, 2009, 6:59 PM
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This site will caculate the fall factor for you and everything. http://www.myoan.net/climbart/climbforcecal.html
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MS1
Jul 17, 2009, 7:08 PM
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Options include: Use a dynamic tether to the anchors rather than the static loop chain. Search "purcell prusik" for one good dynamic tether that is both strong and inexpensive. A spendy alternative would be the sterling chain reactor. Build an anchor and rappel down from above. If you have the technical expertise to construct a good anchor this is safe, but it is also quite time consuming. Have your partner get a good stance well away from the edge. Then clip into the anchors with your tether while setting up the gear, while your partner backs you up with a hip belay from above. This assumes that you trust your partner to give an effective hip catch. Just lead climb the f***er.
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trenchdigger
Jul 17, 2009, 7:15 PM
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karcand wrote: This site will caculate the fall factor for you and everything. http://www.myoan.net/climbart/climbforcecal.html This calculator works just like the Petzl one, assuming the mass is a solid, inflexible object. As I mentioned earlier, this assumption results in a significant error with shorter falls when the malleable human body is exchanged for the solid mass.
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cracklover
Jul 17, 2009, 7:30 PM
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Okay, first of all, if I'm imagining the situation that had you freaked out in the first place - I think you're overreacting, it's no big deal. I've gone places where the anchors are an arm's length below the top of the cliff face, and there's a nice flat top to the cliff. It's just not that big a deal to lie down, reach down to clip stuff in, and set up your TR like that. And having someone hold your ankles or something is a nice backup in case you have a hard time scootching back up over the edge. You're right that the PAS is not the greatest solution, because of the huge forces you'd get from falling from above the anchors directly onto it. Better off just using a plain old nylon sling, which absorbs more force. Better yet, use a purcell prusik. Best yet, just don't fall while you're rigging the anchor. Which brings me back to the first paragraph. Oh, and yeah, you could easily break a biner if the gate happened to get pushed open while you were falling in that scenario. Cheers, GO
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cracklover
Jul 17, 2009, 7:41 PM
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trenchdigger wrote: karcand wrote: This site will caculate the fall factor for you and everything. http://www.myoan.net/climbart/climbforcecal.html This calculator works just like the Petzl one, assuming the mass is a solid, inflexible object. As I mentioned earlier, this assumption results in a significant error with shorter falls when the malleable human body is exchanged for the solid mass. Oh, and aside from the fact that it's totally wrong! GO
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Carnage
Jul 17, 2009, 7:44 PM
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cracklover wrote: trenchdigger wrote: karcand wrote: This site will caculate the fall factor for you and everything. http://www.myoan.net/climbart/climbforcecal.html This calculator works just like the Petzl one, assuming the mass is a solid, inflexible object. As I mentioned earlier, this assumption results in a significant error with shorter falls when the malleable human body is exchanged for the solid mass. Oh, and aside from the fact that it's totally wrong! GO yea, apparently a 20 foot fall on 100 feet of rope is a FF1.2
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jdefazio
Jul 17, 2009, 8:08 PM
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Carnage wrote: "cracklover wrote: Oh, and aside from the fact that it's totally wrong! GO yea, apparently a 20 foot fall on 100 feet of rope is a FF1.2 meh. It is clear what is going on there if you enter "0" for the distance to the anchor for any non-zero length of rope. Not that it becomes any less useless.
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zchandran
Jul 17, 2009, 9:11 PM
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If you're reasonably sure you're not going to fall, wouldn't using a screamer in conjunction with your PAS be the way to go? I've never been in this situation so this is obviously hypothetical. But it seems like throwing a screamer into the mix takes all the risk out of the all-static scenario.
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jt512
Jul 17, 2009, 9:42 PM
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rockreaver wrote: Question: How much force will this generate and will this equipment handle it safely? Also is this the way the equipment was designed to be used? }--The equipment (PAS) made from 2 blue water titan loop chains (18Kn) and 2 Petzl Attache HMS Screwgate Carabiner (23Kn) and Metolius super safe harness.--{ I weigh 175 pounds if I were laying on a ledge and I fell 3 feet and fully weighted and stopped on the above loop chains and carabiners clipped onto Metolius rap-hangers would the system hold? Is there a risk of the carabiners shattering? Here is what's making me ask this: The other day I was watching some top-ropers (two teenage girls) hike up to the canyon rim to rig their rope from the top instead of lead climbing up and rigging the top-rope that way. I saw the dumbest thing I've ever seen. One of them slid out over the edge to rig the sling/anchor while the other held her feet (no I'm not kidding). I thought to myself that they are asking for death. I reasoned that if they had a PAS or two they could have done it more safely but then I caught myself. How? If they used a PAS or two they are still rolling the dice. The anchors were down way over the edge. If they used a PAS (a static system) while down-climbing from the ledge and they slip they are going to static-load the system and maybe shatter the carabiner and take a fall. So I ruled the PAS option out. (Am I right here?) After climbing I hiked up to see what they had to work with. There was nothing. They couldn't have tied into anything to rap down. It was flat. They could have rigged an anchor with 3 cams or stoppers in a low wall about 20 feet back from the edge but that assumes they had cams/stoppers and the rest of the gear to do that and rap off of. ( Is this a safe approach if you don't lead-climb it? You could set 3 stoppers and rig a bomber anchor I think but is that stupid to do?) It stumped me and I was hoping to find a guide that could explain a safe way to do it. If you try to go over the edge and down climb down below the bolts to rig the rope you run the risk of falling and shattering your biners because a PAS isn't dynamic. There is no give in the system at all. At best all I can come up with is putting a screamer/load limiter on at the end of the PAS to try and reduce the fall factor. ( But honestly I decided you either lead-climb it or walk away right?) Do you have suggestions for this situation? How would you do this safely aside from climbing lead from the bottom up which admittedly is much safer than trying to climb down the edge or have someone hold your ankles. Most sport routes are not designed to be safely set up on TR from the top. The anchors are on the face of the climb because they are expected to be clipped on lead. If you want to safely set up a TR, you have to lead the route to do it. Jay
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jt512
Jul 17, 2009, 9:43 PM
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cracklover wrote: trenchdigger wrote: karcand wrote: This site will caculate the fall factor for you and everything. http://www.myoan.net/climbart/climbforcecal.html This calculator works just like the Petzl one, assuming the mass is a solid, inflexible object. As I mentioned earlier, this assumption results in a significant error with shorter falls when the malleable human body is exchanged for the solid mass. Oh, and aside from the fact that it's totally wrong! GO Yeah, it doesn't even calculate the fall factor correctly, never mind the impact force. Plus it won't answer the OP's question, since he's asking about falling onto a PAS. Jay
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rockandlice
Jul 17, 2009, 9:50 PM
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rockreaver wrote: I saw the dumbest thing I've ever seen. One of them slid out over the edge to rig the sling/anchor while the other held her feet (no I'm not kidding). I've done this myself plenty of times before. If the anchors are within reach without extending %50 or more of my body over the edge, and the clifftop is relatively flat with not loose soil, rock, etc., then I'm not too worried about it. If you are freaked about it, wear a harness, and anchor off to a tree or something nearby the clifftop as a back up.
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rockandlice
Jul 17, 2009, 9:51 PM
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jt512 wrote: Most sport routes are not designed to be safely set up on TR from the top. The anchors are on the face of the climb because they are expected to be clipped on lead. If you want to safely set up a TR, you have to lead the route to do it. Jay Why not just rap down to the anchors are set too far from safe reach?
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jt512
Jul 17, 2009, 9:54 PM
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rockandlice wrote: jt512 wrote: Most sport routes are not designed to be safely set up on TR from the top. The anchors are on the face of the climb because they are expected to be clipped on lead. If you want to safely set up a TR, you have to lead the route to do it. Jay Why not just rap down to the anchors are set too far from safe reach? Why not just lead the route? Jay
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cracklover
Jul 17, 2009, 10:06 PM
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jt512 wrote: rockandlice wrote: jt512 wrote: Most sport routes are not designed to be safely set up on TR from the top. The anchors are on the face of the climb because they are expected to be clipped on lead. If you want to safely set up a TR, you have to lead the route to do it. Jay Why not just rap down to the anchors are set too far from safe reach? Why not just lead the route? Jay Either because you can't or don't want to. There's plenty of good reasons for not leading a route. GO
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jt512
Jul 17, 2009, 10:14 PM
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cracklover wrote: jt512 wrote: rockandlice wrote: jt512 wrote: Most sport routes are not designed to be safely set up on TR from the top. The anchors are on the face of the climb because they are expected to be clipped on lead. If you want to safely set up a TR, you have to lead the route to do it. Jay Why not just rap down to the anchors are set too far from safe reach? Why not just lead the route? Jay Either because you can't or don't want to. There's plenty of good reasons for not leading a route. GO Not if it's dangerous to yourself or others to set up a top rope. Jay
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rockandlice
Jul 17, 2009, 10:16 PM
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jt512 wrote: rockandlice wrote: jt512 wrote: Most sport routes are not designed to be safely set up on TR from the top. The anchors are on the face of the climb because they are expected to be clipped on lead. If you want to safely set up a TR, you have to lead the route to do it. Jay Why not just rap down to the anchors are set too far from safe reach? Why not just lead the route? Jay You stated the anchors could not be safely reached without leading the route. To me the statement was false, but I posed the question to find out what your logic behind that statement was. I suppose I don't follow the logic of strictly suggesting leading the climb when posting a reply to a thread in the beginner forum, especially when other logical options exist.
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