Worn Anchors...

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absolutsugarsmurf
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Post by absolutsugarsmurf » Thu Dec 18, 2008 1:59 pm

I've read Kolin's blog for a couple of years. From him and a few of guys on rc.com, Malcom Daily(MDaily, Richard Goldstone(rgold) and and Jim Ewing(sterlingjim) you can learn a lot about the physics principles applied to climbing scenarios. These guys are really looking out for us all.

The worn shuts in the BD test failed at about 11kN, the new shuts at about 6.6kN (if you're surprised at these low numbers just remember that these are open style shuts, not closed hanger-style anchors that are typically found in the Red). As kato pointed out, this wasn't actually due to a higher "strength" of the worn shuts, but rather in their ability to properly maintain the rope position relative to the spine of the shut throughout the loading cycle. This distinction is very, very important. Like carabiners, the shuts are strongest along the spine and weakest when loaded angularly. If Kolin had been able to mantain the rope position perfectly along the spine of the new shut they would have obviously been stronger than the worn shuts. So why when we buy shuts aren't they pre-groved to mantain rope-position along the spine? That should be obvious. The mechanism of failure of open shuts is not due to high dynamic forces, but rather low static force loads causing the opening of the already worn shuts. This could obviously never happen on new shuts, only worn shuts, just more worn than the shuts in the BD tests.

That said, I have to comment on Kolin's interpritation of his own data. The intended function of cold shuts, or any anchor, at the terminus of a climb is to lower or rappel off of, in a predominately static manner. Since the static force applied to an anchor by someone lowering is equal to the climbers weight plus the belayers weight minus frictional losses, a standard lowering scenario only might produce , at most, 2Kn at the anchors, of which there are two sharing the load. So as long as the system can hold more than 2Kn it's good. And new shuts will. Worn shuts might not, it depends on how worn. You're not going to be able to measure that in situ. All Kolin's data tells us is that a un-groved shut will deform under a lower load than a worn shut of the same material thickness after that shut has been worn. That is, a shut that is made of 1cm thick stock will deform before a shut that was made of 2 cm thick and has been worn down in a grove to 1cm thick.

To say that rope groved anchors are stronger is a false conclusion, and I think a dangerous statement to make on the BD website. Also dangerous is to state that the greatest danger of worn shuts it rope sheath damage. Moral of the story is to keep replacing worn anchors and keep using quick draws to TR on.

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Re: Worn Anchors...

Post by Evan » Thu Dec 18, 2008 2:04 pm

kato wrote:
Wes wrote: funny how the grooves make the anchors stronger
The grooves don't make the anchor stronger, they just direct the load onto the strongest part of the anchor. The non-grooved anchor allows the rope to slide out and gain better leverage against the most stressed part of the anchor.
I buy this rationale but overall I am not convinced by the way the test was set up. They should test the new and old shuts with the rope not in the strongest part (i.e. not in the groove) and see what happens. Also, it looks like they are not even testing the same type of anchors.

Did anyone see those biners that came out a while ago with a little roller for the rope where the groove would develop? Need a picture of it. Maybe it was not as dumb as it looked.

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Re: Worn Anchors...

Post by 512OW » Thu Dec 18, 2008 2:29 pm

Evan wrote:
kato wrote:
Wes wrote: funny how the grooves make the anchors stronger
The grooves don't make the anchor stronger, they just direct the load onto the strongest part of the anchor. The non-grooved anchor allows the rope to slide out and gain better leverage against the most stressed part of the anchor.
I buy this rationale but overall I am not convinced by the way the test was set up. They should test the new and old shuts with the rope not in the strongest part (i.e. not in the groove) and see what happens. Also, it looks like they are not even testing the same type of anchors.

Did anyone see those biners that came out a while ago with a little roller for the rope where the groove would develop? Need a picture of it. Maybe it was not as dumb as it looked.
How would you ever lower off of anchors without the rope in the groove? Shouldn't things be tested in a real world manner?

I've used one of those roller biners... they're cool. Just don't fall on one with a really light belayer. They seem to be great for toprope anchors, and I love to use it as the tram biner while cleaning steep routes.
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Post by Lateralus » Thu Dec 18, 2008 5:09 pm

smurf this was Kolin's conclusion


• Rope-grooved cold shuts keep the load in line with the strongest axis and therefore can withstand a higher load before deformation.

he also stated in the first paragraph

(I’m not going to get into the technicalities, pluses or minuses of different kinds of anchors and am not condoning anything in anyway—I’m just looking at only one style of cold shut, one test, two data points, just out of curiosity more than anything.)

I don't see how your incorrect interpretation of Kolin's test makes their website or climbing for that matter any more dangerous than it already is.

PS climbing is dangerous always was and always will be.
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absolutsugarsmurf
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Post by absolutsugarsmurf » Thu Dec 18, 2008 5:41 pm

I'm saying his testing was incomplete and because of that, his conclusion is innacurate. The shut he tested with grooves deformed under a larger load than the ungrooved shut, yes. But he failed to discuss the effects of the most important variable , the percentage of material removed from the groove. At some point, when you remove enough material, the grooved shut will deform before the ungrooved shut, despite the loading direction effect. At what point is this? 50% grooved, 75% grooved, 10% grooved? Since you obviously can't measure this while climbing and is also material and design specific, the only safe procaution is to replace grooved anchors. BD stating on their website that grooved anchors are necessarily stronger than non-grooved anchors could easily cause people to not critically evaulate the condition of worn anchors, and instead just remember "well bd said that grooved anchors are stronger than non-grooved". That to me is dangerous. Made more so by the fact that his conclusions are notated by a bullet and seperated from the body of the text so as to make them easy to pick out, while his testing qualifications are not.

PS Thanks for the reminder that climbing is dangerous. Very insightful. I guess we should never seek to improve the safety of our equipment, information, or techniques, because shit, climbing is dangerous.

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Post by Wes » Thu Dec 18, 2008 5:54 pm

I have replaced a pretty good amount of mank in the red over the years, and to me, what you are saying is wrong. It is wrong to assume that grooves = equal unsafe. They might not be perfect, but they are more then enough to lower. But, if you promote fear mongering about grooves, then people might come upon a grooved anchor, flip out, and do something that is less safe (down climbing, traversing to another set of anchors) or just un-need (adding a locker to the shuts, etc).

What you are promoting is misplaced fear. I think alot of climbers have a heard time determining what is actually unsafe v. what is fine. Like lowering off a single 1/2" quicklink is totally safe, yet I find extra biners on those kind of anchors all the time. Or, I see people at the 3rd/4th/ even 5th bolts worried about which direction the gate is facing, when they are risking ground fall without even realizing it.

Even those tiny little #2 wires would hold as top anchors for lowering. And you could damn near floss with one, so give worn anchors the amount of concern they require, but not more.


absolutsugarsmurf wrote:I'm saying his testing was incomplete and because of that, his conclusion is innacurate. The shut he tested with grooves deformed under a larger load than the ungrooved shut, yes. But he failed to discuss the effects of the most important variable , the percentage of material removed from the groove. At some point, when you remove enough material, the grooved shut will deform before the ungrooved shut, despite the loading direction effect. At what point is this? 50% grooved, 75% grooved, 10% grooved? Since you obviously can't measure this while climbing and is also material and design specific, the only safe procaution is to replace grooved anchors. BD stating on their website that grooved anchors are necessarily stronger than non-grooved anchors could easily cause people to not critically evaulate the condition of worn anchors, and instead just remember "well bd said that grooved anchors are stronger than non-grooved". That to me is dangerous. Made more so by the fact that his conclusions are notated by a bullet and seperated from the body of the text so as to make them easy to pick out, while his testing qualifications are not.

PS Thanks for the reminder that climbing is dangerous. Very insightful. I guess we should never seek to improve the safety of our equipment, information, or techniques, because shit, climbing is dangerous.
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Re: Worn Anchors...

Post by trog » Thu Dec 18, 2008 6:16 pm

512OW wrote:
I've used one of those roller biners... they're cool. Just don't fall on one with a really light belayer. They seem to be great for toprope anchors, and I love to use it as the tram biner while cleaning steep routes.
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Very nice for any meandering route/roof/traverse to reduce drag; not recommended for TR anchors, I guess because pulley is relatively small (rope get off track) or maybe pulley not made to be cleaned/maintained when it gets gunked up as easily as a standard hauling pulley. Wish I had a rack full of them with the wandering gumby routes I've done but cost 3-4X standard wiregate.
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Post by Lateralus » Thu Dec 18, 2008 6:45 pm

well smurf considering what he said
(I added bold to the part you don't seem to get)

(I’m not going to get into the technicalities, pluses or minuses of different kinds of anchors and am not condoning anything in anyway—I’m just looking at only one style of cold shut, one test, two data points, just out of curiosity more than anything.) ,
and by your response it appears you are a dumbass. He didn't say he was



condoning anything in anyway.




(statement placed apart from other words if the bold letters didn't catch your attention)


What does that statement mean to you? Why are you totally disregarding it?


His conclusion with minimal data meant for curiousity was that the shuts he had with grooves (not measured because he CLEARLY said this wasn't a definitive test in anyway) failed at a lower point than the shuts w/o grooves. Interesting!
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Post by kato » Fri Dec 19, 2008 9:55 am

Wes wrote: Even those tiny little #2 wires would hold as top anchors for lowering. And you could damn near floss with one, so give worn anchors the amount of concern they require, but not more.
The wire is under a tensile load and the anchor has a tensile load plus a bending moment. It is a different load case that could produce a dramatically different result.

Not trying to pick on you, but given recent events, it seems worthwhile to point out.
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Post by 512OW » Fri Dec 19, 2008 10:36 am

This has just gotten stupid. You guys need to go climb scary old routes with old gear and get your perspectives straight.
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Post by Myke Dronez » Fri Dec 19, 2008 10:49 am

This was starting to sound like an RC.com pull test gumby scare thread. Thank you Wes. Half worn through shuts are pretty f'n bomber in comparison to the sun bleached tat piles and sickly rhodos most of us have have lowered from at one point or another. The theme to Kolin's tests seems to be that while old, worn gear is better replaced with new, it's still pretty damn strong, and perfectly safe in a realistic situation. I'd be more worried about the damage you can't see- that old mank bolt is gonna sheer clean off while you're worrying about the grooved shut its pinning to the wall.
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Post by rockman » Fri Dec 19, 2008 11:23 am

512OW wrote:This has just gotten stupid. You guys need to go climb scary old routes with old gear and get your perspectives straight.
Agree 100%.
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Post by ynp1 » Fri Dec 19, 2008 11:28 am

512OW, you are such a badass...

i saw a 1/4 bolt break while my partner was lowering out on it. kind of scary...
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Post by 512OW » Fri Dec 19, 2008 11:30 am

ynp1 wrote:512OW, you are such a badass...

i saw a 1/4 bolt break while my partner was lowering out on it. kind of scary...
It was? He was just lowering out... its not like it caused a fall, just made your slow ass aid "climbing" a little bit faster.
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Post by ynp1 » Fri Dec 19, 2008 6:12 pm

didnt cause a fall??? do you know anything about what you try to talk about on here?
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