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Ixs
Big Wall climber
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Jan 13, 2013 - 01:35pm PT
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regards
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captain chaos
climber
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Jan 13, 2013 - 03:03pm PT
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"life is a series of narrow escapes with sighs of relief in between"
Glad you escaped this one Jim... tell Bridwell I say hello, Craig
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donini
Trad climber
Ouray, Colorado
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Topic Author's Reply - Jan 13, 2013 - 04:03pm PT
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Everbody thinks I soiled my underwear. Actually, it happened so unexpectedly and suddenly I wasn't scared at all. I just found myself hanging from the knotted sling and knew I had to do something. A convenient hand jam and a good red camalot placement brought the situation completely back to normal. Never felt nervous, if I had seen it coming the underwear surely would have needed washing.
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le_bruce
climber
Oakland, CA
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Jan 13, 2013 - 06:38pm PT
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You mentioned no leaver was there when you arrived, which means that probably at least one party had rapped and then pulled their rope directly over the sling.
In the desert, the sawing on the sling when a rope is pulled through is even worse given the inevitable sand and grit that find their way into the rope's sheath.
Your story will definitely stick with me and echo back to the surface on future raps. As a guy who likes to climb obscurities in Yosemite, I appreciate the reminder.
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Clint Cummins
Trad climber
SF Bay area, CA
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Jan 13, 2013 - 07:58pm PT
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Yikes.
One lesson is to test "white" slings.
And maybe that nylon goes bad a lot faster in Sedona than in Yosemite and other places that don't routinely go over 100 degrees F?
P.S. cragnshag is my climbing partner, and I thought the plan was not just to send the heaviest person first, but to have the temporary backup in place for them (with enough slack so that it is not directly weighted).
The other way to choose who goes first is who has more people at risk if they don't make it. Haven't had to seriously use this one, fortunately.
Usually we have 2 of cragnshag's really good bolts and quicklink/chainlinks in for anchors, so there's about zero anchor *material* failure risk.
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tradmanclimbs
Ice climber
Pomfert VT
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Jan 13, 2013 - 08:22pm PT
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I was taught the leader went first and the 2nd had to clean the backup.. these days I leave whatever is needed to make it safe...
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Seamstress
Trad climber
Yacolt, WA
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Jan 13, 2013 - 08:32pm PT
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Wiley and experienced. Thanks for sharing. That's not luck - that's listening to that inner voice.
So much for you folks who laugh at me and my redundanitis.
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JLP
Social climber
The internet
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Jan 13, 2013 - 09:25pm PT
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One lesson is to test "white" slings. How would one test them? IMO, if it's white, it can't be trusted.
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SteveW
Trad climber
The state of confusion
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Jan 13, 2013 - 09:27pm PT
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Talk about cool under pressure.
That's JD!
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Clint Cummins
Trad climber
SF Bay area, CA
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Jan 13, 2013 - 10:42pm PT
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How would one test them? IMO, if it's white, it can't be trusted.
Clip your harness to the sling and weight it, then bounce it (requires a backup and a non-fragile back).
You can also do a less severe loading by jerking on it with your arm, or clipping a sling to it and stomping in the sling.
The complete visual inspection that Jim did is also important. It's not equivalent to a full body weight test, though. This is part of the standard sequence you do while still clipped into the rappel rope (if this is a lower anchor in a series). Although sometimes steps get skipped to save time. Redundancy is good....
I've tested plenty of white slings in Yosemite that pass the loading test with my (light) body weight. I also have an occasional relatively new slings whose original color is white (with a single black strand). Most nylon slings are fortunately colored these days. And specta etc. has two colors.
These days I have a tiny knife on my harness, and often spare tied slings in my pack. Often I will untie and remove slings from anchors that have "too many" (> 2) "good" ones, and move them to other anchors that have "too few" ( < 2 ).
Almost all slings I see pass my bounce testing and many look very bad (faded on top, fully faded, frayed partway through, very dirty/moldy, etc.). If I have extra slings with me, I remove and replace. Otherwise I might remove a few of the worst ones if there are still 2-3 semi-bad ones left.
As for trust, I trust the ones I've vigorously tested. And I vigorously test stuff when there is poor/no redundancy, or possibly suspect slings. I don't bounce test stainless 3/8" double-bolt anchors, or colored/non-faded slings.... :-)
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JLP
Social climber
The internet
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Jan 13, 2013 - 11:31pm PT
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Clip your harness to the sling and weight it, then bounce it (requires a backup and a non-fragile back). I understand the whole testing thing, really.
The thing is, let's say the sling can hold 500 lbs for 5 seconds and your testing uses up about 3 seconds of that and you don't notice anything wrong? I think the right answer is not testing - it's hey, this sling is white, can't be trusted, and may fail at a really low force - better have a plan B.
Not that I don't believe in testing everything all the time - but it's mostly to verify that things I already know and trust are all connected - not to expect I can do some kind of material science voodoo testing out in the wild on the individual componants - that's just crazy, really, if you think about it and have done much of this sort of testing in a formal way. You're really just rolling the dice - still. Sample of one and no controls doesn't tell you anything. The sling just can't be white w/o a backup.
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High Fructose Corn Spirit
Gym climber
-A race of corn eaters
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Jan 13, 2013 - 11:38pm PT
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As for trust, I trust the ones I've vigorously tested. +1.
Blind trust: bad.
Empirical, evidence-based trust: good.
Trust (aka faith) can be a tricky animal, no doubt. In relationships. In rock climbing. In belief. But one thing's for sure: blind trust (aka blind faith) is of the worst case, last resort type.
restores my faith in knots jammed into cracks
Which, it's worth noting, ain't a blind faith. ;)
.....
the sling can hold 500 lbs for 5 seconds and your testing uses up about 3 seconds of that
That makes zero sense. Back to science class, mr.
material science voodoo testing... Sample of one and no controls doesn't tell you anything...
Neither does this. Makes zero sense. Nada. Beta: If I were you, I'd not do any more rappelling until you're clear on the basic dynamics involved. (Also, the basic statics.)
I understand the whole testing thing, really.
Not according to your post, you don't.
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Ed Hartouni
Trad climber
Livermore, CA
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Jan 14, 2013 - 02:39am PT
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I'm with JLP on this, actually... and it's because of the type of accident represented in the OP, maybe Donini can elaborate on his habit, that is, whether or not he tested the sling with force before weighting it.
It is certainly true that after inspecting the slings, and cleaning up the station, I might decide that there are good slings there and I can trust my life to them.
But if I have any doubt, independent of testing, I just put a new sling on the anchor. Looking at Donini's picture, I would have put a new sling on the anchor... that's me.
This isn't the first accident, and certainly not the first "near miss" that has occurred with old slings. Maybe you're ok going through the test ritual, but if there is any doubt, why not just contribute to the upkeep of the rap stations and add a sling? and maybe clean up a bit of tat?
It's not so much of an effort... and there is no uncertainty regarding the integrity of the anchor when you do it.
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healyje
Trad climber
Portland, Oregon
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Jan 14, 2013 - 07:12am PT
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Now filed under: 'Old dogs, new tricks'.
Reminds me I did know a guy long ago to whom you could give a gnarly, old, outdoor tomcat and he'd return a sweet house cat after three weeks. He said there is always a way to teach an old cat new tricks. He was expensive, though, and only had one rule - you couldn't ask him how he did it.
It was nice of Jim to be so forthcoming in this case.
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Tony Bird
climber
Northridge, CA
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Jan 14, 2013 - 07:24am PT
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i think you missed my point entirely, ed. it isn't a scientific one, but it could easily become so.
of course everyone is glad when someone survives something like this. we've spent the whole thread telling jim we're glad he's alive and well. for the record, i am too. i'm not suggesting we pick apart the incident. as you say, jim was gracious enough to share it with us. but in his original post he said that he read some sort of technical article which seemed to say how strong an old sling can be. that's what i want to pick apart, the everlovin' article. are you in the camp with moosedrooler such that you never question anything once it gets into a "respectable" publication?
as an aside, i hope dirtbag made coffee. mt. piņos has powdah, powdah, powdah. cold is good. i crashed at 8 pm and now i'm up way too early.
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Clint Cummins
Trad climber
SF Bay area, CA
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Jan 14, 2013 - 08:38am PT
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I agree that testing might potentially weaken a sling or anchor component so that it would then fail under a lower load than if untested.
Such a "test-weakened rappel sling failure" seems unlikely to me, though.
Probably this is based on some years back, where I towed my car with a motley collection of slings, including some 1/2" webbing that I thought was junk.
Nothing broke, in spite of many repeated jerks when accelerating after each stoplight. And much larger loads than we can generate rappelling, even with big guys and lots of gear.
But we want a rule which keeps the risk below an "acceptable" level.
What's acceptable to me might not be acceptable to other folks (even if we had a good estimate of the failure probability), so I don't expect my methods will be best for everyone.
Example rappel anchors with new slings and rings, clean rope:
1. One sling, no rings.
2. One sling, one ring.
3. One sling, two rings.
4. Two slings, no rings.
5. Two slings, one ring.
6. Two slings, two rings.
7. Three slings, three rings.
Every time we add redundancy, we reduce the failure probability.
I'm fine with #1, especially if I think it will never be used again.
I've had partners who insist that #1's risk is too high - they want one of the safer options.
#6 is fairly standard, for a frequently used rappel station.
#7 is safer, though....
Yes, the gear is cheap.
It takes a little effort and time to bring the gear along and add redundancy.
Whether it is worth the extra effort/time depends on your level of acceptable risk and how you value your time.
And the above 7 anchors are a situation where we can have good estimates of the breaking strengths of the components.
The probabiliy of failure is very low in #1 and gets ridiculously low in the others.
So if we can't solve the above, there's no chance in making an easy-to-use rule for making acceptable anchors with partly faded slings.
JLP has a reasonable point that if:
1. a sling "looks/feels bad enough", and
2. we have enough spare webbing,
then we should just replace it instead of testing it.
The main problem is that you have to develop a set of rules for (1.) "looks/feels bad enough" to calibrate them against sling failure probability.
You need testing (by yourself or others) to develop this set of rules.
I do it often when I'm removing tat, because I want to see if I can predict how weak a sling is from its look and feel.
And you might want to do continued random testing of slings that meet your rules for safety, to make sure your rules still work in a new area.
And what if you don't have (2.) sufficient spare tied slings to reach around a big block (Jim's exact situation, 8')? If you have a knife (I carry a tiny one), you can cut off the end of one of your ropes and use that. But there had better be a good reason to do that (it will create other risks and it's not cheap). Spot testing in such a situation is no guarantee you will live if the sling holds, but if the sling fails under test you have learned something important.
Finally(?), testing also tests more than just the slings.
One of the goals is to uncover unobserved flaws in the anchor system.
So I believe testing is still quite useful in the real world.
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drljefe
climber
El Presidio San Augustin del Tucson
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Jan 14, 2013 - 09:50am PT
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If it's white, it ain't right!
bomber
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High Fructose Corn Spirit
Gym climber
-A race of corn eaters
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Jan 14, 2013 - 10:23am PT
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EH wrote,
I'm with JLP on this...
Riley wrote,
I'm with JLP also.
We really shouldnt even have to debate this one.
To be clear, let's take the two specific points I referenced, no better, criticized. You guys are with JPL regarding...
the sling can hold 500 lbs for 5 seconds and your testing uses up about 3 seconds of that Really? Testing uses up time? Citations from either modern engineering physics or life experience, please.
Sample of one and no controls doesn't tell you anything... Really? So if I encountered a slung boulder in the manner described by JD: an old badly weathered 1" sling that I was thinking about rapping from, testing it wouldn't tell me anything? Let's say, I recognize it as weathered, it's testable under daisy chain and in the line of force (a point JD was not clear about), I bounce test it to 8-10 g, it holds, moreover this simple part system still looks same; also taking into account my intention to rappel the line smoothly at 2g max say, precisely because it is a compromised questionable system... then this, according to JPL, "doesn't tell you anything"?
But you're right, Riley, we shouldn't even have to debate this one.
.....
No one's arguing, I don't think, that an extra sling wouldn't have strengthened the system. Geez.
But to not test the system (under load, many times body weight, too, by bouncing, under visual inspection, while backed up) esp when possible, esp one suspected of being dangerous, is neglectful if not foolish. That's the main point. Applies to rapping off old bolts as well as slings, too. Obviously.
Testing the system before use saves lives.
.....
Donini curiously has remained mum (even since my first post) regarding (a) whether this rap station lended itself well to apriori load testing (some don't); (b) whether or not he in fact tested the system (I suspect not).
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donini
Trad climber
Ouray, Colorado
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Topic Author's Reply - Jan 14, 2013 - 10:32am PT
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I didn't test it. I was completely off base rapping on the, obviously, badly UV damaged sling. My point in posting was that even someone who has rappelled as many times as me can make a bonehead decision.
Do Not become blase about rappelling!!!
It is the single most dangerous thing that climbers do!!!
The best climber in the world is not going to change the results of a failed anchor!!!
Diligence....Diligence....Diligence!
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PhilG
Trad climber
The Circuit, Tonasket WA
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Jan 14, 2013 - 10:35am PT
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Jim,
I just hope them younger climbers are listening up and paying attention.
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