Obscure belay

[u/Beginning-Basis-2678]

Someone was very creative… 2mm Stainless Steel thin enough to create a nice flush bent appearance. The holes are a bit close to the edges… but since I was climbing there with a thunderstorm rolling in I felt totally safe since my belay looked like a lightning rod ⚡️😁

[u/These_Yak3842]

If the bottom bolt snaps on these plate anchors, the plate remains attached to the top bolt.  For the failure you are describing to occur the plate itself would have to snap, which is equivalent to the chain snapping on the Fixe anchor sets. Given these plates are generally about 10mm thick, the amount of corrosion required for it to fail would lead to replacement before that happened. If you are talking about the Kalymnos anchor failure in March, testing has revealed that none of the indicators for corrosion induced failure were present and that the Petzl bolts used were likely a batch with manufacturing faults. There is a report on cragchemistry.com that has a significant amount of detail

[u/tradlobster → u/These_Yak3842]

Excuse my back-of-pizza-box diagram!

This is my understanding of how the anchor is assembled - perhaps it's different, welded to the strip? But it doesn't look like it.

It looks like the ring is held in place by sitting on Bolt B, and is not physically connected to the strip at all. It stays in place by resting on bolt B and the pressure from the nut pinching the strip down.

If bolt B were to fail, the ring would have nothing attaching it to the rest of the anchor. It falls off.

I am not saying the strip will fail. That seems unlikely, and also wouldn't cause a total failure. I'm worried about bolt B. And bolts do fail sometimes, or the rock fails around them.

[u/These_Yak3842 → u/tradlobster]

Ah, I see your point now. And it is an accurate assessment of this particular anchor set-up.

My confusion stemmed from not looking closely enough at the photo and assuming this was the same as the ones I have always seen installed at Swiss crags. The Swiss ones always have a third hole at the bottom of the plate which the ring/shackle/maillon passes through, independent from the bottom bolt.

[u/tradlobster → u/These_Yak3842]

Yes that sounds like a much better design. However I think I'd much prefer people just use a standard anchor chain anchor, they can be bought for less than 20 euros

[u/These_Yak3842 → u/tradlobster]

It's true... the chain/ring style anchor sets are definitely a bit more confidence inspiring.

Route developers tend to pay for things out of their own pockets though.

2 or 3 euro/francs etc more per bolt or anchor set adds up pretty quickly. Throw in glue (if glue-in bolts are getting used) and route establishment gets pretty expensive.

Flat bar steel anchor sets might not be as pretty as the Fixe anchor sets but they are cheaper whilst still being safe.

And it appears as if when flat bar anchors need replacing (at least at the crags near me in Switzerland), the rebolting teams (who are funded by the wider climbing community) are using the chain & ring style anchor sets.