UKC

Climbing anchors may not seem to be the most exciting topic for UKC; what is there to know you ask? Surely they are just the things we clip at the top of climbing walls, or maybe at some well-equipped sports crags?

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In reply to UKC Gear:
The extra maillon between the two chains is absolutely baffling to me. I am not sure which failure scenarios it is supposed to cover.

If an anchor fails, then all the force is reported on the other anchor. On the krab side, however the force is shared between 2 krabs. But we haven't fixed any real issue.

If a link or a krab under the maillon fails, then all the force is reported on the other krab and transmitted to both anchors. But given the normal resistance of a single anchor, I don't see again what could be the problem otherwise.

I guess if a krab fails and hte opposite anchor fails, it would catch the failure, but come on, really?

However the extra maillon is causing a third horizontal force on a link designed to take tensions over its large diameter. Not a brilliant idea to say the least.

In reply to drolex:

It might just be there to keep the chains together, and not be in place as a safety feature.

In reply to drolex:

What is that, 8mm chain? Breaking load will be at least 60kN, probably a bit more. So much stronger than it needs to be that it really doesn't matter a toss if it's compromised a wee bit by that maillon.

In reply to dabble:

I think "Product News" is actually a euphemism for "advert" isn't it?

In reply to drolex:

Hi,
The STAL Anchors are pretty over engineered and have a huge margin of safety in the design, in part due to a couple of anchor failures at walls in the UK where one side failed (not STAL!). The maillon is there for a number of reasons but mainly; it brings the chains together, as dell / deepsoup noted, acts as a final back up if one side fails (this is more likely as a failure of the bolt or improper installation) and accounts for foreseeable misuse (e.g. clipping one side or a variation on set up by the operator).

The chain is M10 and very strong - we tested one side to failure and the bolt broke (M12 8.8) at about 40kn in shear and pulled in Axial to 51kn without failure (although heavily deformed). When doing the initial EN compliance tests we tried to break the chain (one side) but gave up when it bent the tester at 74kn - so we are very confident about the loading on the chain.

Have a look at the site and download the user data for more information: http://www.stalclimbing.co.uk/

In reply to UKC Gear:

What is the actuall set-up inside the green plastic affair that forms the anchor?


Chris

In reply to Chris Craggs:


Blu-tack.

In reply to Climbing Wall Services:
Hi, do you have any details on the "couple of anchor failures at walls in the UK"? I'd be interested to know how the anchors failed. Cheers Gareth.

In reply to Climbing Wall Services:

Thanks for the explanation and glad to see it's tested.

Do you have other colours available? I was thinking to put a red one on the Right Unconquerable and a blue one on the Left Unconquerable to help me remember which is which.

In reply to Chris Craggs:

The "puck" acts as a spacer of sorts - and holds the chain in position. The bolt goes through the uppermost link of the chain - very simple - but the puck has also been designed to allow a little airflow reducing capillary action and standing it away from the climbing surface (for wear on the wall)

In reply to drolex:

There is a black version where the chains / components are 316 stainless steel, for external uses (the black is more UV stable), we will get some special ones made for you if you stick to that plan - but might remove the logo

In reply to gejones:

A bit of a touchy subject - the underlying reasons are still in debate - there have been a few failures worldwide as well - the DAV (Germany) put out a notice a couple years ago but very little publicity
- https://www.abcwalls.co.uk/news/fixe-tech-rock-hangars-info/
- https://www.alpenverein.de/chameleon/public/d73c4b0e-7ede-727f-7b53-dbe4fa2...

The two in the UK were pretty much the same.

In reply to deepsoup:


You took the words right off my keyboard there, except there's not much euphemising going on.

In reply to deepsoup:

STAL is a small company (only two of us) and not super savvy on the writing so may have come across a bit weird, but not something we are used to doing - it was harder than we thought it would be!

In reply to Climbing Wall Services:

That's interesting reading, thanks, and certainly not what I was expecting.

But with those failures in mind, and particularly as the underlying cause is still in debate, I'm surprised that STAL chose to shroud the top link in plastic.

In reply to gejones:
The green version is not stainless steel (it is plated like the bolt) hence no part of the anchor could be affected by SCC, however if you read the article on the ABC site, you will note that the process of manipulating the top link of the chain is in question - which does not happen on the STAL anchors - there is no possible weak or brittle point.

As part of the EN standard compliance testing (which was completed by an independent testing house) a corrosion test was completed - all STAL versions passed with no issues.

In reply to Climbing Wall Services:

I'm not questioning the quality of your materials or their fit for purpose.
But if I were a climbing wall owner, ease of inspection would be a prime requirement in light of all failures so far.

In reply to gejones:

I know what you mean and we considered that aspect carefully, the puck can be easily loosened and rotated to check the link / bolt - if desired - but when we considered it, the comparison we made was to the section of the bolt which is sandwiched in the wall and if the level of corrosion on M10 / M12 plated steel components was to become an issue there will be signs on the other sections of chain and bolt. - Again the material we use has been selected because they don't have the issues of the 304 / 316l. So far the walls that have been using them have had a very favourable response - over a year of heavy commecial use and no issues / wear (other than the bits the ropes goes through which are easily replaced).

In reply to Climbing Wall Services:
If inspection is easy, all's good! I've just got my marketing head on today and it's an obvious question to ask. My rational head would have no problem lowering on your anchors

Back to the UK failures - were they also outside and at manually welded links? I wonder how many anchors of this sort exist on real rock - I can't think of any in the UK but I've clipped plenty abroad (I think). The point about redundant rather than equalized set-up being safer in this context was also interesting.

In reply to gejones:

No worries!

Both failures in the UK were at indoor climbing walls with a partially exposed aspect (one side was open to the elements a bit) - I think lots of anchors like that exist on real rock! The UK is a funny environment for SCC - wind makes the entire island a higher risk level (or so I am told). But the real issue is if SCC has nothing to do with it - which is suspected - and there is a fundamental problem with the process. It is interesting that there has been no further notice after the advice to back anchors up - which is concerning. This whole thing, is one of the reasons we started STAL - I tried to find other suppliers but there just we not any.

In reply to Climbing Wall Services:

Not at all. It comes across like an advert but that's because, well, it is.

What you don't often see on these 'product news' threads though is the people behind the product getting involved in an interesting conversation, so kudos for that.

In reply to drolex:

For the cost involved in adding it, to me it seems like a reasonable thing to do given the extra redundancy it provides.

In reply to Timmd:

If you're leading and arrive at a twin independent anchor, it might not be the best idea but it isn't mad just to clip one of them to lower off, as that's just the same as lowering from any bolt on the route. The maillon between the chains will give redundancy for that, but more importantly will offer more genuine redundancy for when numpties see leaders doing that and presume it's fine to top-rope through just one as well.

In reply to UKC Gear:

The local climbing wall has been changing out their old ones for these. Haven't paid much attention apart from noticing the colour! No different in use than the old ones but good to see the reasoning behind it.

In reply to john arran:


I suppose the difference between lowering off from a bolt on a route, and lowering off from one clip at the top, is that as the climber being lowered strips the route, if the clip at the top fails, they could end up falling some distance, and potentially hit the ground?

In reply to UKC Gear:

I went to Harrogate climbing centre at the weekend where they have the STAL clips and I was pleasantly surprised by them. I quite liked the fact that the chains were held away from the wall which made clipping a bit more efficient, and they are nice and shiny (for now) which is always a bonus. I was sceptical when I first heard of the idea but having used them I can say I'm convinced of there usefulness and if I ran/ owned a climbing wall I would be installing these.
My only concern is there is no screw gate so top roping off the clips would be a sketchy option.

In reply to Boris\'s Johnson:


Opposed snapgates are as safe, if not safer, than a single screwgate - there is no way a toprope will come free. I imagine it's kinder on both the rope and krabs too.

In reply to danm:

Fair enough, thanks for the clarification.

In reply to drolex:

If by hazard the wall fixing is crap! ... then when one anchor is ripped out of the wall, the chain and lump of wall will not skid down the rope and smack you on the hands (causing you to let go!) or in the face or other nasty place ......
clearly it's all OTT ... but then such anchors should be OTT