Non-MR maillons

[georgenorth]

Because the rope has presumably been there longer than the maillon and fabric has a shorter shelf life than metal.

The ‘shelf life’ is pretty irrelevant when it comes to leaving kit underground. The question should be, is it safe to use? The rope is in good condition and is safe to use, despite the fact that it could be 30 years old (or more!).

The maillon clearly needs replacing, preferably with a stainless one.

 

[Bob Mehew]

A fair number of years ago I reported some research done on the strength of SRT ropes subject to different usages (one use being one abseil down and one prussic up). The results showed a substantial loss of strength as measured by the number of drops taken to break a sample. I also tested one rope which had been in situ underground for several tens of years and found it had a substantially reduced strength. Though to be fair, I was also given a sample of rope of the same type and similar age but had just sat in a garage for all of its life and had retained a substantial strength.

And by the way, in considering leaving hardware underground, one should bear in mind possible other corrosion mechanisms. BCA Equipment and Techniques committee issued a statement a while ago after considering a paper on the topic of chloride stress corrosion cracking. I was surprised to find evidence of chloride ions strengths sufficient to cause concern even at places like Malham Tarn.

 

[JAshley73]

Thinking about the cause of cracking, I've always assumed that the manufacturing process requires forming the threads on the straight rod, fitting the nut and then bending the rod into shape, as the nut can't be fitted once it's bent. Getting the alignment of the threads must be a key part of the process. Whatever coating is used has to be applied before the nut is fitted, so has to be protected while bending. Does anyone know different? Is there another way to make them that I've missed?

Well, while I don't have inside-knowledge of how they're made, I can tell a couple things just based on my manufacturing experience, and general observation...

1- The 'visible' threads on a mallion are tapered - thus, why fully closing them requires the use of a spanner. If the visible threads were straight along their length - relying on pressing against a shoulder to maintain tension (tightness) - then they would be much more susceptible to opening via vibration. Being tapered, varying thickness of the plating won't have any significant effect on their function.

2- I don't think zinc-plating would necessarily seize the mating nut & threads together. I could be wrong on this, but plating post-assembly wouldn't surprise me.

 

[Ian Ball]

From my spares bag - I'm afraid I'm in the Safety First contingent, which partly explains why I'm always skint.

View attachment 21966

What a waste of packaging

 

[IanWalker]

Here’s an example of some certified, bought at a caving shop, PPE rated maillons from today. I think they’ve been underground for about 15 years. There’s no doubt hundreds of them in this state throughout the Dales.

I’m strongly of the opinion that using unmarked 316 quick links would be a safer option.

View attachment 21965

I'm glad you shared this. It shows the obvious problem for our community that people habitually decide to install and leave behind corrodable gear in a corrosive environment, and then not maintain it.

PPE rated, certifed, stainless maillons are available for sale over the counter in the Dales. This photo could have been a shining example of fixed gear being thoughtfully installed. (Pun intended.)

 

[pwhole]

What a waste of packaging

Ah, but I re-use the grip-bags for all sorts of things, like teabags when working away, so there's no waste there. The instruction leaflets are too hard for toilet paper, so they go in recycling

 

[georgenorth]

I'm glad you shared this. It shows the obvious problem for our community that people habitually decide to install and leave behind corrodable gear in a corrosive environment, and then not maintain it.

PPE rated, certifed, stainless maillons are available for sale over the counter in the Dales. This photo could have been a shining example of fixed gear being thoughtfully installed. (Pun intended.)

I agree that there’s got to be a better way than leaving corrodable gear down caves.

Unfortunately leaving dozens of £14 maillons underground isn’t affordable for myself, or most other people. Obviously if some rich benefactor is willing to pay for ppe rated maillons then I’d happily use them! Until then, I reckon that using unmarked stainless hardwear is a big increase in safety over the current use of bzp maillons, and even worse, old alloy carabiners.

 

[JAshley73]

I agree that there’s got to be a better way than leaving corrodable gear down caves.

Unfortunately leaving dozens of £14 maillons underground isn’t affordable for myself, or most other people. Obviously if some rich benefactor is willing to pay for ppe rated maillons then I’d happily use them!

Are club funds available for permanent rigging?

I often read about UK caving clubs having loaner personal gear for SRT - which sounds bonkers to me. Are there not club, or "group" funds for permanent rigging?

 

[PeteHall]

Are club funds available for permanent rigging?

I often read about UK caving clubs having loaner personal gear for SRT - which sounds bonkers to me. Are there not club, or "group" funds for permanent rigging?

Depends on the club.

Clubs with huts tend to have much higher running costs and liabilities, so may be less generous with funding projects?

Certainly, the three clubs I'm a member of that don't have huts are pretty generous funding projects, socials etc, as we don't have a great deal else to spend subs on!

I'm not aware of similar funding from my club with a hut, though I don't get involved with the meetings or committee there, so I may be wrong.

 

[Badlad]

FYI JAshley

Regional Councils and the National Body generally fund stainless steel anchor placements for SRT and well as conservation materials and materials for securing access.

Clubs, particularly university clubs, will hold personal SRT sets for training and beginner use. Those who take up the sport will be expected to buy their own soon after.

Clubs will all hold stocks of ropes, ladders, karabiners etc for use by their members.

Clubs and individuals groups, usually diggers or divers, will rig caves for the duration of their projects. Sometimes funded by their club but also by the individuals involved.

 

[georgenorth]

Are club funds available for permanent rigging?

I often read about UK caving clubs having loaner personal gear for SRT - which sounds bonkers to me. Are there not club, or "group" funds for permanent rigging?

Pretty much what Badlad said. The vast majority of the things that get left rigged are off the beaten track (pitches up mostly). I wouldn’t expect a club or the CNCC to pay for it anyway, because it would benefit so few cavers (if any!).