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c4c
Apr 1, 2010, 12:03 PM
Post #26 of 34
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I work for an acct premier vendor member as an inspector. You would want to bolt through the 4x6. You would want to use LEAP anchors or similar product for leading edge protection. If you were going to be teaching lead climbing where the participant was on a top-rope then the SS hangers with a SS bolt would be accetable. It sounds as if you are using an acct inspector so they should be able to answer your question based on your specific method of use.
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tehbillzor
Apr 4, 2010, 5:50 PM
Post #27 of 34
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Registered: Jan 26, 2010
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USnavy wrote: ceramiclover wrote: That said I would look at rebuilding the frame of your wall if you really want to lead on this wall. Lastly, be careful if you do a multi-pitch class on the wall. Factor two falls are not forgiving and if someone takes one, I can almost guarantee you an injury is going to come with it. how would their be a factor 2 fall?
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davidnn5
Apr 4, 2010, 9:33 PM
Post #28 of 34
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tehbillzor wrote: USnavy wrote: ceramiclover wrote: That said I would look at rebuilding the frame of your wall if you really want to lead on this wall. Lastly, be careful if you do a multi-pitch class on the wall. Factor two falls are not forgiving and if someone takes one, I can almost guarantee you an injury is going to come with it. how would their be a factor 2 fall? Belay is set up on second pitch (e.g. on a ledge). Climber ascends 10 feet, falls past belayer and takes a 20 foot ride (20 foot fall on 10 feet of rope). Factor 2 fall. Christ, I cheesetitted your cheesetit!
(This post was edited by davidnn5 on Apr 4, 2010, 9:34 PM)
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tehbillzor
Apr 5, 2010, 3:32 AM
Post #29 of 34
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True david, but that is a weak f2 fall. with your 20 ft fall, a 80kg (176 lb) climber, static belay, a rope with 7.6% elongation, and an 80kg belayer the average impact force is 11KN.
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I_do
Apr 5, 2010, 1:53 PM
Post #30 of 34
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tehbillzor wrote: True david, but that is a weak f2 fall. with your 20 ft fall, a 80kg (176 lb) climber, static belay, a rope with 7.6% elongation, and an 80kg belayer the average impact force is 11KN. And you don't think that could break someone's back or dislocate a few vertebra? And what's the peak force in such a fall?
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tehbillzor
Apr 5, 2010, 2:22 PM
Post #31 of 34
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I_do wrote: tehbillzor wrote: True david, but that is a weak f2 fall. with your 20 ft fall, a 80kg (176 lb) climber, static belay, a rope with 7.6% elongation, and an 80kg belayer the average impact force is 11KN. And you don't think that could break someone's back or dislocate a few vertebra? And what's the peak force in such a fall? 11KN is the "peak force" which is experienced once the rope is fully stretched out. my point is that even with a moron giving you a totally static belay on lead their is only 11 KN of force exerted on the anchors. assuming that the belayer is clipped to at least 2 bolts at the belay station each bolt receive about 6 KN. My point was not to say that the person falling isn't going to receive a shock, but rather that the bolts don't have to be bomb proof to hold that fall. Although beefing up protection is always a good idea.
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shoo
Apr 5, 2010, 2:48 PM
Post #32 of 34
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You are all missing the point here. Even if the OP somehow manages to have a perfectly adequate and safe bolting system (which is doubtful to start with), the wall will be used and possibly overseen by incompetent people. The users will have the assumption that they are always safe, and their instructors are experts and would never tell them wrong or let them do anything that could possibly get them hurt. Even if the current instructors / staff or whatever are perfectly competent, that will not always be true. Eventually, it will be overseen by people who don't know what they are doing. It will happen. And even if all of the instructors and staff are perfectly competent, the clientele will not be, and that's bad enough. After having run camp climbing facilities, teaching countless climbing courses, and running a variety of climbing trips for noobs, my personal rule for institutional climbing is to assume everyone is an idiot, but treat them like intelligent, wonderful people. It's not necessarily their fault that they are idiots, and with proper instruction they will not always be so. Combine incompetence with a false sense of security in a highly skill-dependent situation, bad things will happen. Edited 'cause I feel like being nicer today. Consider yourself lucky
(This post was edited by shoo on Apr 5, 2010, 5:19 PM)
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USnavy
Apr 6, 2010, 3:47 AM
Post #33 of 34
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tehbillzor wrote: I_do wrote: tehbillzor wrote: True david, but that is a weak f2 fall. with your 20 ft fall, a 80kg (176 lb) climber, static belay, a rope with 7.6% elongation, and an 80kg belayer the average impact force is 11KN. And you don't think that could break someone's back or dislocate a few vertebra? And what's the peak force in such a fall? point is that even with a moron giving you a totally static belay on lead their is only 11 KN of force exerted on the anchors. assuming that the belayer is clipped to at least 2 bolts at the belay station each bolt receive about 6 KN. My point was not to say that the person falling isn't going to receive a shock, but rather that the bolts don't have to be bomb proof to hold that fall.. Not even close. First, you always clip the anchor so if you fall you fall into the belay station and not directly onto the belay device. When you clip the anchor (or any piece of pro) you have to take into account the pulley factor which increases the force on the top anchor well above that of what the climber sees. So if the climber saw 11 kN at his harness, and he redirected the rope through a draw on the belay station, the belay station would see 16 - 18 kN. And that’s on a single bolt. That much force can severely deform hangers, bend 1/2" bolts, and break some 3/8" bolts. So yes, that is a serious issue and yes the bolts have to be completely bomber which is why I always recommend the use of ½” bolts to build a belay station. That’s the reason why UIAA requires biners and bolts (in tension mode) to hold 20 kN. The maximum allowable force that the climber can see is 12 kN. If the climber sees 12 kN, the top anchor will see about 20. That’s where that number comes form.
(This post was edited by USnavy on Apr 6, 2010, 3:52 AM)
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JimTitt
Apr 16, 2010, 7:55 PM
Post #34 of 34
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You CAN clip the anchor but this is to reduce the loading on the belayer himself (reduce the impact to a level where he can possibly brake the rope), not the belay. As you yourself point out IF you clip the belay bolt this increases the loading on the gear you clipped by nearly double. The earlier poster was correct in that the strength of the belay bolts is not the relevant issue if you don´t clip as in a FF2 however as it is difficult to brake a rope to 11kN with any device available today so both arguments are inherently meaningless. The strength of the next bolt out is however of some importance! Standard lead climbing bolts to the current European wall standard using 22mm ply panels are a stock hanger, 10mm bolt and 10cm square 6mm thick steel backing plate. There is no requirement to fasten through the supporting structure. They may be fixed back to the building structure to reduce the framing loading. Belays are two such anchors joined by chain. For multi-pitch routes the bolting pattern after the belay starts again as for the start of the route.
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