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paulraphael
May 9, 2005, 7:49 PM
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In reply to: If you take 5 whippers every day on the same biner and climb 100 days per year, the biner will last 5 years. .
and if this sounds like your life, maybe it's time to pony up and buy a few more biners!
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kyote321
May 9, 2005, 8:08 PM
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biners used in sport climbing take a lot of abuse, but it is short falls. the trad biner will take the odd long fall. i wouln't take my sport biners, with the top biner gouged from bolt wear, to scary placement on a trad climb. i keep a few fresh draws and slings for this purpose.
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jt512
May 9, 2005, 8:31 PM
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In reply to: If you take the typical load of falling (about 10kN), a carabiner will last about 5000 cycles. Now if you add normal safety margin of 50%, you got 2500 falls left. If you take 5 whippers every day on the same biner and climb 100 days per year, the biner will last 5 years. Since I do only trad climbing and fall perhaps once during 10 days of climbing, my biners will last longer than I will.
But consider, say, a biner of a fixed draw at the crux of a popular sport climb. Let's say that the biner holds 50 lead falls a week, 50 weeks a year. That's 2500 cycles in a single year. Fortunately, 10 kN is not a typical force on a biner in a lead fall. Most falls generate lower impact forces.
-Jay
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chronicle
May 9, 2005, 8:47 PM
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In reply to: In reply to: If you take the typical load of falling (about 10kN), a carabiner will last about 5000 cycles. Now if you add normal safety margin of 50%, you got 2500 falls left. If you take 5 whippers every day on the same biner and climb 100 days per year, the biner will last 5 years. Since I do only trad climbing and fall perhaps once during 10 days of climbing, my biners will last longer than I will. But consider, say, a biner of a fixed draw at the crux of a popular sport climb. Let's say that the biner holds 50 lead falls a week, 50 weeks a year. That's 2500 cycles in a single year. Fortunately, 10 kN is not a typical force on a biner in a lead fall. Most falls generate lower impact forces. -Jay
I won't trust ANY fixed draws. No offense to anyone, but I don't know how long that thing has been up there, how many falls have been on it, how many wet/dry cycles the webbing has had, etc. Plus I feel that fixed draws are like pre-paced trad gear.
Good info though.
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adnix
May 9, 2005, 8:55 PM
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I added some safety margin there. A typical load is 4-7kN according to the Italian study. But if you belay with Grigri, 8kN is achievable. The table on the study gives 10000 cycles with 8kN. This would suggest four years as maximum life in your case without any margin. The biner will brake eventually.
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climbsomething
May 9, 2005, 9:16 PM
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In reply to: In reply to: If you take 5 whippers every day on the same biner and climb 100 days per year, the biner will last 5 years. . and if this sounds like your life, maybe it's time to pony up and buy a few more biners!
(who owns something like 32 draws)
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yosemite
May 9, 2005, 9:22 PM
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Warning. Public service announcement follows.
In the context of this discussion.....
Brake means to stop or arrest a fall.
Break means to fail and come apart in little pieces.
Thank you.
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saxfiend
May 10, 2005, 3:31 AM
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In reply to: In reply to: If you take the typical load of falling (about 10kN), a carabiner will last about 5000 cycles. Now if you add normal safety margin of 50%, you got 2500 falls left. If you take 5 whippers every day on the same biner and climb 100 days per year, the biner will last 5 years. Since I do only trad climbing and fall perhaps once during 10 days of climbing, my biners will last longer than I will. But consider, say, a biner of a fixed draw at the crux of a popular sport climb. Let's say that the biner holds 50 lead falls a week, 50 weeks a year. That's 2500 cycles in a single year. Fortunately, 10 kN is not a typical force on a biner in a lead fall. Most falls generate lower impact forces. -Jay
I don't think I've ever read of a biner failing during a fall, but of course that doesn't mean it doesn't happen.
JL
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chriss
May 10, 2005, 4:18 AM
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In reply to: In reply to: I would like to know where you heard something like this? AustriAlpin gives 350 hours of usage to a carabiner in paragliding use. This is one of the sources: http://www.dhv.de/...oteslist.php?lang=EN
That's a really good source for safety information on paragliding. But means nothing for climbing carabiners.
1st mention of biner failure,
"After several fractures of aluminium harnesscarabiner Parafly Automatic from AustriAlpin during use in 2003 and 2004, the manufacturer was asked to prove fatigue strength against vibration. The last deadline was 1. March 2005. This proof has not been shown up today. Tests conducted in the order of DHV to aluminium harnesscarabiner Parafly Automatic from AustriAlpin showed low values of fatigue strength against vibration. The in flight safety is gravely affected. The DHV has decided on the following precautionary safety measure:
All harness carabiners Parafly Automatic by Austrialpin, must not be used any more."
Vibration issues are not to great in climbing biners. Not to mention this is a specialty biner.
2nd,
"Paraglider harness, carabiner for paragliding harnesses, Sup`Air twistlock aluminium carabiner for 40mm webbing
Since 1992 more than 300.000 pieces of the Sup`Air aluminium twistlock carabiner for 40 mm webbing are beeing used.
There are no accidents known because of malfunction of this carabiner. It is a known fact however, that aluminium carabiners have a limited life time. Nobody is able to tell exactly how long the life time of aluminium carabiners is. Sup`Air and Aerosport International recommend to exchange aluminium carabiners after 5 years or 500 hrs. of flying time."
Actually no information here at all. Just recommend 5 yrs or 500 hrs. Also a specialtiy biner.
Carabiners failing under bodyweight? I need more.
chris
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jt512
May 10, 2005, 4:37 AM
Post #36 of 44
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In reply to: In reply to: In reply to: If you take the typical load of falling (about 10kN), a carabiner will last about 5000 cycles. Now if you add normal safety margin of 50%, you got 2500 falls left. If you take 5 whippers every day on the same biner and climb 100 days per year, the biner will last 5 years. Since I do only trad climbing and fall perhaps once during 10 days of climbing, my biners will last longer than I will. But consider, say, a biner of a fixed draw at the crux of a popular sport climb. Let's say that the biner holds 50 lead falls a week, 50 weeks a year. That's 2500 cycles in a single year. Fortunately, 10 kN is not a typical force on a biner in a lead fall. Most falls generate lower impact forces. -Jay Moving from the theoretical to the actual, how often has anyone here seen a biner fail in a fall, either in the high-stress scenario Jay describes above or with draws off your rack (and for the sake of this question, leave cross-loaded biners out of the equation)? I don't think I've ever read of a biner failing during a fall, but of course that doesn't mean it doesn't happen. JL
I've heard secondhand of many biners breaking, all either presumed or known to have been loaded with the gate open. I have never heard of a biner breaking in nomral use when loaded with the gate closed. Oddly enough, the only biner I ever saw that had been fallen on when crossloaded didn't break; the wire gate merely bent.
-Jay
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jt512
May 10, 2005, 4:45 AM
Post #37 of 44
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In reply to: In reply to: In reply to: If you take 5 whippers every day on the same biner and climb 100 days per year, the biner will last 5 years. . and if this sounds like your life, maybe it's time to pony up and buy a few more biners! If this sounds like your life, your name might be Jay T.! :) (who owns something like 32 draws)
Actually, my intuition is that if you fell that much on the same biner in practice, you'd retire the biner due to wear from the rope long before you significantly weakened the biner. Every time you fall, friction from the rope wears down the biner's rope-bearing surface, until, eventually, a groove appears. I start getting nervous, and will retire a biner, when the groove gets close to half-way through it, which, I suspect, happens long before any significant weakening due to cyclic loading occurs.
-Jay
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adnix
May 10, 2005, 6:12 AM
Post #38 of 44
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In reply to: Moving from the theoretical to the actual, how often has anyone here seen a biner fail in a fall, either in the high-stress scenario Jay describes above or with draws off your rack (and for the sake of this question, leave cross-loaded biners out of the equation)?
Ot the other hand I know three indoor wall owners and they said they've never seen a carabiner fail. In indoor use the you might get the amounts JT mentioned. But I guess most owners replace carabiners on regular basis.
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adnix
May 10, 2005, 6:15 AM
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In reply to: Actually, my intuition is that if you fell that much on the same biner in practice, you'd retire the biner due to wear from the rope long before you significantly weakened the biner. |
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paulraphael
May 10, 2005, 4:05 PM
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I've heard secondhand of many biners breaking, all either presumed or known to have been loaded with the gate open. I have never heard of a biner breaking in nomral use when loaded with the gate closed. Oddly enough, the only biner I ever saw that had been fallen on when crossloaded didn't break; the wire gate merely bent.
-Jay
Biners actually break with some regularity. Not often, but it they do seem like the one piece of gear that fails (not counting dicey placements) often enough for it to not be a freak occurence.
Like you suggested, it's mostly because of the gate being open at the peak of the fall. But there are quite a few instances of biners breaking in closed gate falls. It's easy to tell by examining the biner, by the way ... they fail differently in closed gate and open gate falls.
The hypothesis I've seen (from qc engineers) isn't fatigue ... it's the biners being loaded closer to the gate side than what they were designed for.
When they test biners, they use skinny metal pins to pull the biners apart. This concentrates the load at the strongest point of the biner, right next to the spine. A sling centers the load a bit closer to the gate by a few milimeters, weakening the biner a significant amount. A fat sling does it even more. And a sling that tugs on the biner at a weird angle can drastically reduce the strength.
Chris Harmstom has said that he's never seen piece of wired trad gear rated at 10kn or more fail. This suggests that in real life, at least in trad situations not using a gri gri, falls rarely if ever put over 10kn of force on the top piece. The frequency of biner failures suggests that they fail below their rated strength with some regularity, even once in a while with the gate closed. Research and common sense suggest that it's unlikely for a single (non-fixed) biner to ever take enough falls for fatigue to be an issue, so it seems like the best place to focus attention (for both manufacturers and climbers) is on the point and direction of biner loading.
I haven't seen any tests of this, but I'm suspecting that using skinny slings (like the mammut shoe laces) will actually improve the working strength of a biner. Avoiding odd load angles, or situations where the biner isn't free to align itself, definitely will.
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adnix
May 10, 2005, 8:43 PM
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In reply to: Chris Harmstom has said that he's never seen piece of wired trad gear rated at 10kn or more fail.
And the other issue of slings. Tests of one manufacturer support this claim. A carabiner that has open gate rated 10kN will hold 8,7kN with normal sling and 9,1kN with dyneema.
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paulraphael
May 10, 2005, 11:08 PM
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Could the nut have been fixed for a while before it broke? Fixed nuts often have heavily damaged cables from people trying to unfix them. Especially on alpine routes where the nut tool of choice is typically an ice tool.
I seriously doubt the possibility of generating 12 or even 10kn on the top piece in an alpine environment. Considering that the highest impact force ropes generate 9kn or so in a near factor 2 test fall with an absolutely static belay. This would put roughly 13kn on the top piece. Dynamic belay devices don't let you come anywhere near this ... in real world situations they slip at several hundred pounds of braking force.
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adnix
May 11, 2005, 6:25 AM
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In reply to: Could the nut have been fixed for a while before it broke?
1. Someone trying to clean the route (ie. rip all fixed gear). It was fixed really good and deep, which means you won't really bother trying to steal it out of curiosity.
2. Someone self belaying on it with a sling and falling. This thing will cause quite good loads.
3. The thing being damaged before someone fell on it. Either due to numerous falls or some other reason.
Since it was fixed just below the crux move of pitch one (the move was quite awkward really) my bet would be on option 2 or 3.
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guangzhou
May 11, 2005, 8:29 AM
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Actually, the short falls with very little rope out comnonly taken on sport routes will create much more damage than the long falls on those long trad lines.
I have some binner that are 3 years old that I trust completel, while I have retired ther binners in less than five years.
The gate action is a good indicator of the biner. Lose pins and to much side to side play in the gate means the binner is worn out.
Of course, two old retired binners, opposite and opposed make great rap rings.
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