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majid_sabet
Jun 22, 2007, 12:28 AM
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with a bungee cord ?
In reply to: poomasta wrote:Yeah, I should have clarified: we use a grigri. I've heard of the dynamic belay technique where you allow rope to slide through an ATC, but frankly that scares the hell out of me. I'm fine using an ATC, but I want my belayer to lock that rope off when i fall. So...questions remains: could you safely rig a belay anchor with a bungee cord to provide a dynamic belay? (qualificiations: belaying with a grigri, single pitch sport climbs)
http://www.rockclimbing.com/..._reply;so=ASC;mh=25;
(This post was edited by majid_sabet on Jun 22, 2007, 12:29 AM)
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hosh
Jun 22, 2007, 12:39 AM
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majid_sabet wrote: with a bungee cord ? In reply to: poomasta wrote:Yeah, I should have clarified: we use a grigri. I've heard of the dynamic belay technique where you allow rope to slide through an ATC, but frankly that scares the hell out of me. I'm fine using an ATC, but I want my belayer to lock that rope off when i fall. So...questions remains: could you safely rig a belay anchor with a bungee cord to provide a dynamic belay? (qualificiations: belaying with a grigri, single pitch sport climbs)
I understand where a question like this may come from, but I have trouble understanding why a question like this would get "serious" attention and even it's own thread. Let's drift it in the direction of what dinner food would make the best trad gear... Perhaps a can of corned beef slung with some string cheese?
hosh.
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col
Jun 22, 2007, 12:41 AM
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Define safely in this context, i.e.
1. safer then not having it and not dynamically being belayed,
2. safer then not having and being dynamically belayed,
3. safer then free soloing,
or
4. are you concerned that bungee cord is inherently dangerous?
I think what we need here is a diagram of what is being proposed...
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col
Jun 22, 2007, 12:55 AM
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hosh wrote: ....Let's drift it in the direction of what dinner food would make the best trad gear...
I think that any tinned food would be robust enough, but if we have to sling it also using food... mmm... maybe some sort of pasta of noodles...
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SkaFreak
Jun 22, 2007, 12:56 AM
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It should be perfectly safe, assuming that you have a bungee cord that is rated for the kind of forces generated in a fall in climbing. If you did ever do it, I'm sure you'd want to have it backed up too. The concern with that would be if the bungee snapped, you'd be letting the leader fall even farther onto basically a static belay, so would do more harm than good. I'd say just don't bother trying. If you could get a rig that would work and be safe, it wouldn't be worth the hastle of setting up/using it.
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bent_gate
Jun 22, 2007, 1:05 AM
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hosh wrote: ...I understand where a question like this may come from, but I have trouble understanding why a question like this would get "serious" attention and even it's own thread...
col wrote: I think what we need here is a diagram of what is being proposed...
Or how about more useless threads like making up more provacative anagrams (rearranged letters) out of Majid's name:
Favorite Anagrams of Majid_Sabet
Current Favorite:
Majid_Sabet >>> Jams A Bidet
Runners Up:
Majid_Sabet >>> I'm A Bad Jest
Majid_Sabet >>> Emit Sad Jab
Majid_Sabet >>> Bad Site Jam
Sassiest:
Majid_Sabet >>> Jab Dis Meat
Create your own!
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silascl
Jun 22, 2007, 1:27 AM
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Seems like a pretty dumb idea, but you don't seem to get that the comparison is to being unanchored. To me, there is not a huge difference, except for whatever damage the bungee cord manages to cause when you take a big whipper and it snaps in half.
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maldaly
Jun 22, 2007, 1:36 AM
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majid, I'm going to honor this post and let the possiility slide by that it may be a troll. Whatever. When you use UIAA/CE climbing gear you already have a bungee cord built in. It's called the rope. Sure, a self locking (Grigri/Cinch/whatever) device in the system may increase the load over a tube style device but you should rarely, if ever, have cause for that load to be very high. The PADOVA study found that for real loads (people) in real situations with real gear, the highest load they could register at the belay device with a F2 fall was around 7kN. A tube style device was 3-5. So, in theory, if you could find a load limiter (Yates Screamer) that would activate at 5kN you could limit the load at the belay device to 5 kN. If you;re woriied about this it's probably better to have the limiter at the first piece of pro.
Mal
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shockabuku
Jun 22, 2007, 4:21 AM
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People jump off bridges with bungee cords tied to them - they come strong enough. I imagine you'd just have to be carefull how much stretch you got so you didn't deck. Seems like a silly idea however.
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drector
Jun 22, 2007, 6:02 AM
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Majid_Sabet >>> Mad At Jibes.
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robotsweat
Jun 22, 2007, 6:05 AM
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Isn't there a pretty good up bounce associated with bungee cords ? It would suck to fall 20 feet and then come rebounding back up with 15 feet of energy and only make it 5 because you ended up meteoring into a roof.
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epoch
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Jun 22, 2007, 11:05 AM
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I'm going to pretend that I didn't read this thread.
I want my 2 minutes back Majid...
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markc
Jun 22, 2007, 12:24 PM
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poomasta wrote: In light of the thread drift here, I have, what I think to be, a semi-related question. my wife is about 60 lbs lighter than me and will occasionally go flying if i take a good size fall. under certain circumstances, we'll anchor while she belays. the biggest draw back here is the loss of the dynamic belay...and she complains about the whiplash This is possibly a crazy idea, but what if you included a dynamic link in the anchor, like a high strength bungee cord?
This was the original question, which was possibly misinterpreted by majid, or at least not represented well at the outset of the thread. The OP wasn't seeking to incorporate a bungee in the top anchor, but in a ground anchor. With a much lighter partner and a Gri-Gri, he's looking for ways to have a dynamic belay while preventing his wife from going for a ride. I just wanted to clarify.
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cracklover
Jun 22, 2007, 2:28 PM
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For clarification - here's what the guy's proposing:
GO
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markc
Jun 22, 2007, 2:53 PM
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cracklover wrote: For clarification - here's what the guy's proposing: * snip image *
Thanks, Gabe. I especially like the demonstrated difference in weight.
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dingus
Jun 22, 2007, 2:59 PM
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cracklover wrote: For clarification - here's what the guy's proposing: [IMG]http://i8.tinypic.com/6gdsuf8.jpg[/IMG] GO
That was me on my last sport lead. I need some of that ganja in my belay system too.
DMT
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cracklover
Jun 22, 2007, 3:24 PM
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Thanks, markc.
dingus wrote: cracklover wrote: For clarification - here's what the guy's proposing: [IMG]http://i8.tinypic.com/6gdsuf8.jpg[/IMG] GO That was me on my last sport lead. I need some of that ganja in my belay system too. DMT
Bungee, not Ganja. Focus, Dingus, focus! By the way, speaking of sport, did you know there's a climb called Milktoast at Rumney? I'll be climbing there this weekend - I'll plan to do it in your honor.
Cheers,
GO
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reg
Jun 22, 2007, 3:40 PM
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sure - with a V large diameter bunge!
"give me a lever long enough and i'll move the world"
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vector
Jun 22, 2007, 4:16 PM
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Wow! His wife is a hottie!
cracklover wrote: For clarification - here's what the guy's proposing: [IMG]http://i8.tinypic.com/6gdsuf8.jpg[/IMG]GO
edited to say, "I don't know how to make Cracklover's image show in the quote."
(This post was edited by vector on Jun 22, 2007, 4:19 PM)
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majid_sabet
Jun 22, 2007, 5:15 PM
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cracklover wrote: For clarification - here's what the guy's proposing: [IMG]http://i8.tinypic.com/6gdsuf8.jpg[/IMG] GO
Poomasta is proposing this and not me
click link below my post to see where this bungee thing came from.
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dingus
Jun 22, 2007, 5:25 PM
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cracklover wrote: By the way, speaking of sport, did you know there's a climb called Milktoast at Rumney? I'll be climbing there this weekend - I'll plan to do it in your honor. Cheers, GO
"I did not know that." The Great karnac
Rumnye must be a place of light and laughter and intelligence and grace, to suffer such a route!
Is it like this Milktoast?
Cheers buddy
DMT
ps. That pic - reminds me of Sat morning cartoons... running dude in suspenders catches them on something and REBOUND! Smack into the tree, very funny image
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robbovius
Jun 22, 2007, 5:28 PM
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What, you can't defeat teh stupid site autosyntax that makes pictures only show up once? lightweights. whadaya retahded? it's easy...see?
cracklover wrote: For clarification - here's what the guy's proposing: GO
(This post was edited by robbovius on Jun 22, 2007, 5:28 PM)
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robbovius
Jun 22, 2007, 5:30 PM
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and a second method to regurgitate a [pic ture in a thread...
cracklover wrote: For clarification - here's what the guy's proposing: GO |
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cracklover
Jun 22, 2007, 5:55 PM
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dingus wrote: Is it like this Milktoast?
Nah - East Coast/West Coast thing. Your climbs tend to be bigger. So here is our correspondingly small East Coast Milktoast:
In reply to: ps. That pic - reminds me of Sat morning cartoons... running dude in suspenders catches them on something and REBOUND! Smack into the tree, very funny image
Not as funny as some of Majid's. I take my helmet off to him.
GO
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paulraphael
Jun 22, 2007, 6:22 PM
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Your belay is plenty dynamic even without a bungee cord. An ATC can only provide 2 to 4 kn of braking force, depending on how big a gorilla the belayer is. So either the rope stretch and friction are going to keep the force below that level, or the belayer will get lifted and keep it below that level, or the rope will slip despite the belayer's best efforts. Not often much need for more dynamics than that.
The trouble with bungee cords in general is that they're TOO stretchy. It takes very little force to lengthen them a lot, which means you'll be adding a lot of fall distance to get a significant amount of energy absorption. Not to mention the bounce issues already mentioned.
If you used a super thick bungee cord (or a bundle of them) that was stiff enough to do much good, you'd have something that behaved quite a bit like ... a climbing rope.
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