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Simpson’s Pot - Anchors Rope wear

Votes on original discussion now stand at 103, with just over 90% (93) in favour of chains and just under 10% (10) not (are there any IC bolts already installed on a popular pull through route?)
 
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Just for the record, and hopefully to keep things in perspective.

The Swinsto/ Simpsons anchor “project” is now complete.

EXCEPT for the 3 locations.

Slit pot alternative.
Great Aven

Slit Pot “direct” (This pitch has graciously been taken over by Sam)

Be assured I am committed to finishing off this project and have no issues whatsoever in working to the will of the committee and will work to any timescale required.

I trust debates and arguments will be kept about the subject matter and not go “personal” 😃

Ian P
 
In your reply to Matt, you wrote "If the volunteer does not wish to do a proper job, then this should be shelved." I understood you to mean that you expected the volunteers doing the work on Simpson Pot to take the rigorous approach that you suggested, and that not doing so was not doing a proper job. That seemed to me to be unnecessarily critical of those individuals. If that wasn't what you meant, please would you clarify?
@ChrisB - Ian Patrick has long ago written that he wants to do a proper job, and I have no reason to doubt that.

I am trying not to make this about the individual. My concern centres around the lack of information and evidence about the proposed solution.
 
‘Industry’ standard is 10% or 1mm whichever happens first for wear on metal. I cannot see how anyone would justify setting precedent of waiting for 50% - that would be crazy!

And before anyone jumps at me - I know we are not professional/commercial/industry, and are caving recreationally, but, 50%.. come on
If Bolt Products make 6mm and 8mm hangers and the smaller are still strong enough (I doubt they would make them if they weren't) then on that basis alone a 44% loss in metal on the bigger ones would be acceptable.
And wear is still permitted on the smaller one.

I think our insurers might have something to say about officially deviating from the industry best practice of 10% or 1mm maximum allowable wear.

A club trip leader may be treated as if they were acting in a professional capacity if there was a serious accident. Unfortunately, this would probably only be decided in a court room, and it's always best to avoid those.
Then you think it would be sensible to advise that nobody should do Simpsons without a working vernier gauge or, better, until the Slit Pot bolts have been replaced?
 
Does wear make sharper edges that could cut or chafe a rope (especially on a pull through) Id imagine this would cause a problem sooner than the metal failing
 
Then you think it would be sensible to advise that nobody should do Simpsons without a working vernier gauge....
You shouldn't need verniers to measure 1mm of wear on a carabiner or Maillon. You can usually easily feel it with your fingers. This should be done as part of any pre-use check, particularly for any fixed anchors and/or connectors.

There isn't going to be a serious accident caused by this amount of wear.
Assuming you mean a maximum 10% or 1mm of wear then you are correct that there probably isn't going to be a serious accident caused by this amount of wear.

Does wear make sharper edges that could cut or chafe a rope (especially on a pull through) Id imagine this would cause a problem sooner than the metal failing
I would imagine the amount of acceptable wear that Chocolate fireguard suggests could lead to the rope bending over too tight an edge which could cause damage to the rope.
 
I think 1mm is in part based on a comment in a UIAA document . I suspect the logic for this is based on if 1mm wear on a visible part of the krab, what wear is likely to have occurred on the hidden parts like the pin on which the gate hinges. But I admit that is pure speculation. Looking at at EN 959 for rock anchors, the minimum thickness is greater than 2.9 mm, though that part of the specification comes from a diagram of a plate style anchor, rather than a rod anchor. Whilst I agree applying a 1mm limit seems ridiculous for a P style anchor, it is difficult to ignore it given its status. However, thanks to the work of Simon Wilson, we do now seem to have a means of extracting P anchors without overly damaging the rock such that new anchors can be replaced into the existing hole. So replacing an anchor after 30 or so years when the wear becomes visible seems a reasonable approach. But I am not sure I would like to argue that in a court without a lot more work. And I am aware that there are other mechanisms like stress corrosion cracking which could seriously impact on strength without them being visible.
 
It’s a bit of chain. And a ring. Attached to existing anchors. To solve a problem which catches people out. And make life easier for folk to enjoy caving.
If your sense of moral and aesthetic outrage is so triggered by this then you’ll be horrified to hear that valley entrance isn’t natural! For that matter neither is that gate you walk through. (Don’t bother with committee pot, I’ve heard it’s full of scaffolding!)!
Some of the posts on here are ridiculous.
Get a grip, apply some perspective.
Put the chains in, if they work great, if not take them out.
Or try and drag everything down to semantics, endless wrangling over whether a heavily modified and used cave might get an extra hole in its wall, which it won’t, or whether a short metal chain might so upset the fragile sensibilities of people and make all the volunteers who help the CNCC provide a really good service to northern cavers think “f**k this I won’t bother suggesting anything again” and give up.
 
You shouldn't need verniers to measure 1mm of wear on a carabiner or Maillon. You can usually easily feel it with your fingers. This should be done as part of any pre-use check, particularly for any fixed anchors and/or connectors.


Assuming you mean a maximum 10% or 1mm of wear then you are correct that there probably isn't going to be a serious accident caused by this amount of wear.


I would imagine the amount of acceptable wear that Chocolate fireguard suggests could lead to the rope bending over too tight an edge which could cause damage to the rope.
OK, I give in.
I wasn't seriously suggesting the bolts should be left for another 50 years, or that vernier gauges should be part of normal caving gear.

I was just gently blowing on the feebly glowing embers of common sense, in the hope that they'll still be there when we realise we need them again.
 
I think 1mm is in part based on a comment in a UIAA document .

I'm not so sure about this. I remember discussing it within IRATA soon after LOLER was introduced in 1998. I seem to remember Denny Moorhouse recommending the maximum 10% or 1mm acceptable wear during an IRATA Assessor's workshop at his factory around this time. I also learned about it when I first did the Lyon PPE examination course about 20 years ago. I also carry out LOLER examinations and the same maximum wear amounts for e.g., lifting shackles, are recommended by most of the lifting gear manufacturers as well as the Lifting Equipment Engineers Association (LEEA).
 
Hi Jaa, you seem to be upset, sorry about that. I do disagree with you and it's fine. I would just like to check, how do you know the chains are going on existing anchors?

Perhaps a query for the other thread as this is about the wear discovered on the anchors rather than the proposal to use a fixed aid
 
Of course popular climbs will get more usage in a day than most caving routes do in a week or possibly month, so this is what BMC say:

"Re-equipping: correctly specified resin bolts have an exceptionally long lifetime. When re-equipping a route, consider resin bolts to be the default option. Re-equipping implies that a route is popular enough or good enough to be worth the effort of using glue-ins. Opting for the longest lasting solution when re-equipping reduces the number of bolt placements in the long term and can extend the lifespan of the route.

Popularity: resin bolts are generally very strong, and will generally stand up better to sustained, intensive use than expansion bolts will. This makes them the ideal choice for very popular crags and routes.

Rock type and quality: for testing purposes bolts are placed in a block of standard concrete with a compressive strength of 50MPa. In the field, rock quality and hardness can vary a great deal and this should be taken into account when choosing the bolt type to place, as they may not perform as well as in their test specification. 10mm expansion bolts are only suitable for hard rock, whilst 12mm expansion bolts can be used on hard to medium rock types. By choosing a longer length as the rock gets softer, resin bolts can be used on almost any climbable rock type. Some rock may contain voids, cracks or weak layers, in which case resin bolts are also preferred. See Appendix A for rock compressive strength data.

Corrosive environment: environments are split into three classes in the update to the EN959 standard. Each class has a range of specified materials which may be used, and a description of the intended usage location. It is worth noting that resin bolts generally have a better resistance to corrosion than expansion bolts for a given material class, especially if they contain no exposed welds, and that forthcoming standards are likely to recommend designs and manufacturing methods which aim to minimise the various forms of corrosion which have been found to affect anchors. See Appendix B for a discussion of corrosion issues found in climbing bolts and belays and Appendix C for the EN959 classification table."
 
Hmm, perhaps we should consider using resin bolts in caves in future? They sound like the bees knees. 🤔:LOL:

It’s useful to see what the BMC say (and what you quoted in the other thread too) (y)
 
Unfortunately it doesn't have a specification for when to replace, but appendix E expands:

"Resin belay anchors – a pair of resin anchors each with an enlarged eye. Simple, affordable and with the lowest visual impact. Any wear will require replacement of the anchor, so only
suitable for unpopular and poorly frequented routes.


Expansion bolt with belay hanger – a pair of expansion anchors with a special belay hanger either made of shaped and welded cylindrical rod, or with a ring welded in place. These have a low visual impact and the ease of placement that expansion bolts provide.

Rings and maillons – the simplest way to convert a twin bolt belay into one which has easily replaceable parts. Rings last a long time because wear is evenly spread, as long as they are free to rotate. Availability is limited to AISI 316 material (class 2), with care needed to ensure parts meet the 25kN requirement in EN959. Best sourced from a bolt manufacturer although there are some very nicely made rings available from marine fabricators and suppliers.

Chain belay sets - available in two basic layouts. V-shape are equalised but are the most expensive option. L-shape are cheaper and although not equalised (the top bolt is not loaded) this shouldn’t be an issue unless the primary anchor fails. Options available in AISI316 and other materials including some class 1 such as Titanium.

Further options – belay bolts and rings all have one major downside. They require the rope to be untied and rethreaded, which if done incorrectly can result in serious injury or death. For this reason, some installers may choose to opt for a different attachment system where
rethreading is not required. These include ram’s horns and karabiners, and can be used both on pairs of bolts or instead of the ring on a chain belay set. Whilst safer in principle, they still require training and experience to be used correctly and will not prepare a novice for when they travel elsewhere where they need to rethread."

Not that the final paragraph is applicable in our case, but ram's horns were suggested elsewhere.
 
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