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cliffhanger
Trad climber
California
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I think so much blind faith is misplaced when it comes to an aluminum ring. It may be good for 1000's of rappels or top rope falls but eventually fatigue is going to make barely visible cracks, unbeknownst to the next party. I'm all for doubling up as many things as possible.
If the probability of something failing is 1 out of 100,000, using 2 makes it not 2x safer but 100,000 times safer. Doubling up makes it exponentially safer, p^2.
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Thorgon
Big Wall climber
Sedr Woolley, WA
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The Chief: Do you still have a picture of that manky Juniper we rapped off at Whitney Portal during the thunderstorm BITD? Post that one, scared the sh*t out of me!!! Hehehe
Thor
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TomCochrane
Trad climber
Boulder Creek CA
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It is a real eye opener to get involved in testing aluminum aerospace components. Bead-blasting the surface followed by dye-penetrate testing will show up serious cracks that are otherwise completely invisible to your eye.
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Paul Martzen
Trad climber
Fresno
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If you are not comfortable testing your gear in the field in a pragmatic manner you are always going to be afraid if things are not exactly the way you have been taught or are used to. If you do know how to test things in the field, then you are better able to improvise and deal with changing conditions.
If you are descending a climbing route there are few reasons not to have redundant anchors and slings. If it is a trade route, put in two or more bolts with chains. Having two rap rings or quick links means safer and the rope pulls easier.
Coming off a big mountain brings up other questions. Do you have enough gear to get all the way down? How can you leave the minimum amount of gear and still be safe? How can you test marginal anchors without killing yourself? How can you put the least amount of stress on your anchors?
Canyoneering brings up a variety of similar additional questions. How many raps might there be in this canyon? How much webbing and how many rapids should I bring? If I bring a bolt kit, how many bolts do I bring? Do I trust anchors that I find from previous parties? Do I rebuild the existing anchors or use some of them?
I have placed double bolts and chains in canyons and come back the next year to find the chains eroded to nothing. What was left of the chains was like toothpicks! Do I trust the bolts or add new ones every year? How can I test them in the field?
In many areas bolts are not used in canyons. Anchors are built from what is available each year. Weird maybe, but it is an interesting game and an interesting art. Suppose you come into a canyon with no bolts but you bring 150 feet of brand new webbing. You do a few drops where good anchors are 5 to 10 feet back from the lip. You decide to double up the webbing for redundancy. If you use loops you just used 50 feet of webbing for an anchor 10 feet back from the lip. If you tie off the webbing around the anchor, then run it single strand (gasp! Horror!) out to the lip, maybe you only use 15 to 20 feet of webbing for a non redundant anchor sling. What if the anchor is 15 or 20 feet back from the lip and you think there might be another 10 or 15 raps to go?
If you are worried about brand new webbing failing and you don't know how to test if it will hold the body weight forces encountered in rappelling, you could..... post on supertopo!
But seriously. On rock climb rappel routes the slings and rings might be there for years and there is seldom a reason to not back things up. In many canyons the anchors won't be there next year and have to be rebuilt fresh. You are going to be trusting whatever gear you brought in and whatever anchors you build yourself. It is just a different situation. The same basic principles apply, but some of the rules of thumb are different.
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Clint Cummins
Trad climber
SF Bay area, CA
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> If the probability of something failing is 1 out of 100,000, using 2 makes it not 2x safer but 100,000 times safer. Doubling up makes it exponentially safer, p^2.
Only if the risks are independent, and there are no other anchor components to fail.
[I do agree that double ring failure is independent, but the other components are important].
2 rings on a slung dead bush do not decrease chances of failure significantly, because the bush failing is a higher probability than the rings.
Say you have a dead bush with a .3 chance of failing, and a good sling with .00001 chance of failing (probably the true chance is < .00001 ) .
3 ways to for the anchor to fail (assuming independence of risks):
1. bush fails, sling holds: Pr = .3*.99999
2. bush holds, sling fails: Pr = .7*.00001
3. both fail: Pr = .3*.00001 (maybe hard for both to fail at the same time!)
(the total probability of failure is slightly over .3 : .3000007 )
1 way the anchor holds:
4. both elements hold: Pr = .7*.99999 = (1 - .3000007)
If you add a second sling, Pr(anchor holds) = .7*.99999*.99999
so Pr(anchor fails) = 1 - .7*.99999*.99999 = .300014 .
Not significantly different from .3000007 , in my view.
More relevant - 2 cams behind the same flake are not too good if the flake is loose and peels off. (It happened to J at the base of South By Southwest; and it nearly happened to me there, but when I tested the cams, I saw the flake visibly expand).
So you try to place gear in an independent crack (sometimes none is available), and test.
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tradmanclimbs
Ice climber
Pomfert VT
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Jun 10, 2010 - 12:05am PT
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Clint is on track for what I have been trying to say. Don't get all anal about the rings if the webbing sucks or the tree is bunk. The rings are the least of your worries. BTW I would bet my lifes saveings that the failure rate for modern rap rings in actual rapelling situations is mopre like 1 in 10 million, not one in 100,000. Adding a 2nd rap ring to prevent something that has never happened.....
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donini
Trad climber
Ouray, Colorado
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Jun 10, 2010 - 12:08am PT
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Who doesn't rap off of single links all day?
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davidji
Social climber
CA
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Jun 10, 2010 - 12:11am PT
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nutjob wrote:I'd have a heart attack rapping off a single rap-ring.
Didn't we do it? If I'm leaving it, I'll happily rap off a single thin aluminum rap ring and single fresh 9/16" sling. I could remember wrong, but I thought we did. Of course I'll rap of a used one too, but that may not be a stellar idea.
Ed Hartouni wrote: I've been using the fat (and phat) Omega-Pacific solid aluminum ring a lot recently... trust just one of those no problem...
I tried those after getting low on the thin, light ones. 3x the weight according to online specs. This time I think I'll buy a mix of those and SMC rings...
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Captain...or Skully
Social climber
Seriously, Man, I didn't know she was Your sister.
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Jun 10, 2010 - 12:25am PT
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What if you rapped off a single point with NO biner or ring?
Sling on a Horn. We lived.
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gimmeslack
Trad climber
VA
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Jun 10, 2010 - 04:53am PT
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Tho' I've never had to do it, somewhere I've seen suggestion to add a little tied loop of prusik cord as backup to single biner or ring. Doesn't take long to snip $0.39 worth of cordolette and tie a knot.
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Clint Cummins
Trad climber
SF Bay area, CA
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Jun 10, 2010 - 06:04am PT
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> What if you rapped off a single point with NO biner or ring?
> Sling on a Horn. We lived.
Yes.
If I'm doing some multi-rap bail with no existing fixed anchors, I'm leaving slings and no rings or biners. I never carry rings except if I plan ahead of time to improve an existing fixed anchor. And a sling is fine for a single use rap. If it is a shared multiple use anchor, then a ring will keep the slings good for a longer time.
Some people think you can burn through a sling with one person rapping on different diameter ropes, because the rope slips through the sling due to differential stretch and/or diff. friction in the ATC. But awhile back, John Bouchard showed that you can't saw through a sling with a clean rope. With a muddy rope, you can do it, though. So I don't leave a ring or biner if it's a single-use anchor.
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healyje
Trad climber
Portland, Oregon
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Jun 10, 2010 - 06:25am PT
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Are those Dolt nuts? Surely he didn't use THOSE did he??
Are you kidding, one hole dolts and clogs are the mainstay of Larry's rack. I love climbing with him and seeing who can do the strangest protection possible.
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tradmanclimbs
Ice climber
Pomfert VT
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Jun 10, 2010 - 08:59am PT
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Stizzo. that is exactly my point. If you look at the history of rap anchor failures it is always the old slings failing, old bolts failing, old dog chain failing. Never once have I ever heard of a biner failing (rapelling)or a modern rap ring, 3/8th logging chain or 5/16th and larger rapide failing. Of course common sense dictates that if you find worn rings at a station you add a biner.
If we get to a station and the slings are good and it has a single locking biner or a single good ring and you feel the need to add a biner to the station that is fine. I will go last and clean that biner for you and I will live.
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tradmanclimbs
Ice climber
Pomfert VT
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Jun 10, 2010 - 09:05am PT
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It boils down to rational and irational fear.
You are hanging there 1,000ft off the deck and you look at that 3/8th" rapide that is strong enough to break your climbing rope and then some and you tell yourself that you are going to die. That is irational fear.
You look at the 50 year old bolts and 15 year old webbing that the rapide is attached to and you say, Self, we are gonna die! That is rational fear!
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Thorgon
Big Wall climber
Sedr Woolley, WA
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Jun 10, 2010 - 11:31pm PT
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Skully is back!!! AAARRRGGG!!!
Thor
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SpeedyTaco
Mountain climber
Baldy
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Mar 11, 2011 - 12:12am PT
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That would be my pic Chief posted awhile back. Nice eh?
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Forest
Trad climber
Denver, CO
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Mar 11, 2011 - 12:42am PT
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I'm a big fan of "wrap 2, pull 2, tie it all in a big overhand"
viola - redundancy.
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adatesman
climber
philadelphia, pa
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Mar 11, 2011 - 01:52am PT
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If you're going to bump the thread SpeedyTaco, I'm curious what the current consensus is regarding OP's hollow/rolled/coined rap rings is. They are (were?... not sure they still make them now that they went the forged route?) rated to 14kN, which is far more than a rap _should_ put on them and more than a single stopper would be rated at. Yet conventional wisdom seems to be always use 2 of them. I've never understood why this is, but given how little they cost never paid much mind to leaving the extra one. Has consensus changed now that gear manufacturers has seemingly moved to higher strength forged rings and has this impacted what's acceptable for a box-store quicklink?
Playing around with the puller the hollow rings seem go oval well before failure load, so personally I'm fine with a single one so long as it looks in decent condition. Then again, I'm fine with knotted webbing securely wedged behind a constriction, so YMMV.
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dougs510
Social climber
down south
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Mar 11, 2011 - 01:55am PT
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Man, I've rapped off of roots with a sling and biner. It's scary, which makes it all the more dicey.... Sometimes, you just gotta do whatcha gotta do to get off the mountain.
I got away with it, maybe luck, maybe not. Don't be skeard. Everybody gotta die sometime Red...
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Brian in SLC
Social climber
Salt Lake City, UT
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Mar 11, 2011 - 11:44am PT
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But awhile back, John Bouchard showed that you can't saw through a sling with a clean rope. With a muddy rope, you can do it, though. So I don't leave a ring or biner if it's a single-use anchor.
That's absolutely not true.
Doug Hansen (of Hansen Mountaineering fame) in Provo has a rigging video where he saws through a piece of one inch webbing with a climbing rope, by hand, in under a second. Sobering and a bit frightening to watch.
There also was a successful lawsuit by a gal here who was TR'd through a piece of webbing by her purported "experienced" partner. The sling cut through when she was lowered only a few feet, she plummetted to the ground, and was hurt fairly bad.
Its easy enough to replicate yourself at home. I've done it. Clean rope? No problem. Saws right through a sling in no time.
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