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WARNING: 169 kg breaking strength lower offs. |
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9-Mar-2009 12:24:58 PM
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This biner was removed from the top of "These People are Sandwiches" at Shipley upper. It was a single point and looked like a nice stainless wiregate. An eagle eyed Victoria saw a crack (possibly it was more open under body weight) and retired it.
At this point it looked like a standard bent wire biner with an unnecessary weld in it.
I had assumed there would be some awesone weld defect and I could rabbit along about residual stress, and so i broke it with the gate open to preserve the fracture surface.
It broke at 169 kg. Now with the gate closed it would undoubtably be stronger, probabaly more like 350kg. Still not enuff I say.
Once I looked at the broken surface I got a shock, there was a lot of corrosion and some very big grains.
As a preliminary result, it looks like it's cast (weak, poor toughness, poor corrosion resistance, rapid fatigue) rather than being made from bent bar. A rough calc at 10 lowers a week showed it would have grown through wall in a year.
If you see one of these, use 2, or back up some other way. The plain bent bar unwelded variety should be ok. I'm going to section this and look a bit more closely
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9-Mar-2009 12:31:44 PM
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>WARNING: 169 kg breaking strength lower offs.
Would be bad news to top-rope or dog some moves off these too!
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9-Mar-2009 1:26:55 PM
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I've seen (and lowered off) these things at Medlow Bath. Old Salt and Manana come to mind. I'd be happy to help replace them this weekend.
edit:
Maybe I'm too quick to suggest replacing them. You said "it looked like a standard bent wire biner " - is there a standard biner for lower offs that are stronger? How would we recognize the standard versus this one?
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9-Mar-2009 2:02:37 PM
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I think it would be good for a person handier with words than I to really spell out the massive difference between force and wieght on an anchor and how a little difference in fall distance hugely increases force in words for the non mathematicly inclined. ie a tight top rope with a 80kg climber is within limit on a 170kg anchor as long as the anchor is perfect but with 2m of slack in the system your looking at 10 times the required strength in the system.
I suppose what I'm saying is just because you can HANG a truck off it doesn't mean you can DROP a body off it and the things pictured are only good to hang 2 bodies off.
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9-Mar-2009 2:14:50 PM
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... and if someone was being lowered off that same anchor, then the load would be double the climbers weight on the anchor, as opposed to them simply abseiling off it?
~> Easy to exceed 170 kg in that instance, especially if the lowering off was not 'smooth as' ...
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9-Mar-2009 3:11:27 PM
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On 9/03/2009 yankinoz wrote:
>I've seen (and lowered off) these things at Medlow Bath. Old Salt and
>Manana come to mind. I'd be happy to help replace them this weekend.
>
>edit:
>Maybe I'm too quick to suggest replacing them. You said "it looked like
>a standard bent wire biner " - is there a standard biner for lower offs
>that are stronger? How would we recognize the standard versus this one?
The one on Maņana is fine - I put it there - and it is backed up by a separate ring bolt through which the rope should be threaded. If you do find a problem with gear on that or any other route of mine please contact me and I'll get onto it. Note that in general it's poor form to go hacking at a route without consulting the FA first. Of course if the FA isn't interested in required maintenance then that's a different story.
I've never been happy about the one on Old Salt as it is the only piece supporting the rope (although the chain from which it hangs has three carrots). I get the willies when I see people top roping through it without at least a backup quickdraw. If you're interested in doing something with it PM me and I'll give you contact details for the FA.
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9-Mar-2009 3:27:20 PM
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ah, i forgot about the ring bolt on Maņana.
Sorry if I sounded like I was off to hack into anything as that wasn't my intent. I'm merely offering to assist if something needs to be fixed :-)
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9-Mar-2009 3:58:44 PM
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On 9/03/2009 yankinoz wrote:
>ah, i forgot about the ring bolt on Maņana.
>
>Sorry if I sounded like I was off to hack into anything as that wasn't
>my intent. I'm merely offering to assist if something needs to be fixed
>:-)
No worries. As I say, if you have the equipment and know-how, Old Salt could be improved simply by adding a ring, or glue-in carrot + hanger + shackle, beside the existing spring-clip. Then there would be redundancy. I suspect that the spring-clip is bomber, as it has seen hundreds of ascents and if it was defective it would have broken early in its life. The guy who placed it owned a gym at the time so I'm pretty sure it would have been a proper load-rated piece. However it is better to have two anchor pieces!
(Note that the guy who equipped the route was not the person named as FA. The equipper gave the route away. There's a bit of a story there...).
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9-Mar-2009 6:06:54 PM
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Does Jaws still have a single wire gate loweroff? (wave wall)
Is it a potential failure?
Would think it sees alot of traffic...
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9-Mar-2009 6:10:13 PM
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Just out of interest what brand was it?
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9-Mar-2009 11:26:25 PM
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i seem to remember a single lower off on jaws,... though it might have been a steel krab
rather than a wire gate. I remember setting draws for a toprope and wishing there was
something else there when I went up to clean it off.
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10-Mar-2009 7:30:19 AM
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there are 2 old screw gates on each anchor of Jaws, Off the Lip, Split Wave, messy but very safe and effective.
if you have any old screwgates, just put a small worm/hose clmap on them to keep them in place
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10-Mar-2009 7:34:35 AM
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Just to be clear:-
these are bad
No strength rating, possibly cast, no signs of welding, a mould line on the inside where it hasn't been polished off
These are good
"The FIXE Sport Anchor is designed specifically for single-pitch sport climbs and climbing gyms. The high strength, 30kn and easy use, makes a pair of these Top Anchors an outstanding choice."
Bent 10mm rod, rated. But they still recommend using them in pairs
So what to do? Replace any cast or otherwise suspect units with a shackle or an old screwgate worm-clamped to the anchor. Try to make redundancy, have 2 independent lower points, connected sperately. Looks like I'll be carrying a bit of hardware around for the next few weeks
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11-Mar-2009 5:02:09 PM
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So, do we know where else these might be?
I'll ask Mitch, has anyone else placed these?
Take a shifter or hacksaw to renove them and then replace them with an old CLIMBING biner. You can fix it to the chain with a hoseclamp or similar
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11-Mar-2009 5:13:33 PM
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Are these the same clip-and-goes that were sold at climbinganchors.com.au for the last few years? If so
there are quite a few out in the real world i'm afraid.
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11-Mar-2009 5:18:00 PM
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Thanks very much Mike,this type of proactive research/stuff is an excellant way of not only maintaining good routes etc but making me/us aware of how/what to anchor routes etc
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11-Mar-2009 5:25:47 PM
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Don't know if the same necessarily but I thought there was a pair of something similar at the top of Mental Fatigue and Looks Poxable at Berowra last time I was out there?
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11-Mar-2009 5:58:12 PM
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On 11/03/2009 mikl law wrote:
>So, do we know where else these might be?
>I'll ask Mitch, has anyone else placed these?
I found a few in a useless spot once and then relocated them to Gateway, damn I'll have to move them
again...
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11-Mar-2009 7:27:19 PM
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I Think These are the style I had Neil
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11-Mar-2009 7:34:31 PM
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Bomber @ 2X!
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