Author Topic: DCA & the BCA anchoring scheme (split from Anchors/P-Bolts - Treak Cliff Cavern)  (Read 508 times)

Offline bobdearman

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Another point you might like to dwell on is that it is the policy of the BCA Equipment & Techniques Committee not to test bolts after they have been installed. DCA has always disagreed with this policy on the grounds that it is possible to get an incorrect resin mix and consequently Hydrajaws tests are carried out to EN959 subsequent to all bolt installations within their remit..
« Last Edit: February 19, 2019, 03:07:38 pm by MarkS »

Offline andrewmc

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Re: DCA and the BCA anchoring scheme
« Reply #1 on: February 17, 2019, 07:33:22 am »
DCA has always disagreed with this policy on the grounds that it is possible to get an incorrect resin mix and consequently Hydrajaws tests are carried out to EN959 subsequent to all bolt installations within their remit..

I don't believe there is no post-installation test for EN959 mountaineering anchors. I don't know of any other group anywhere in the world that routinely tests mountaineering resin anchors after installation. EN959 anchors are required to hold (I think) 20kn axially, but they are only tested to destruction and so may exhibit deformation at much lower loads.

You are obviously confusing yourself with the test for industrial anchors that fall under EN795. It is of course fine to test industrially tested anchors (basically just the Petzl ones) to that standard. However, it is going outside of the manufacturer's recommendations to test an EN959 anchor after installation.

If you test a BP anchor that has been placed with no resin to 6kN, two things may occur:
You deform the eye
You still fail to pull the bolt out

This is of course an argument that has been had before, with every regional council except DCA deciding to follow the EN959 standard and standard practice throughout mountaineering generally...

Offline Pete K

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Re: DCA and the BCA anchoring scheme
« Reply #2 on: February 17, 2019, 08:39:16 am »
If you lot in the north are happy to hang off, or put your name to, non-proof tested anchors then fill your boots. 6kN for 15 seconds does nothing to a well placed anchor and I think most cavers in Derbyshire would appreciate the extra effort to ensure their safety. You can't test a BP anchor dry in shear, they get pulled axially and there is no deformation at that test load.

Anyway, I suspect the OP was simply using the generic term 'P' anchor to refer to a resin anchor with a rounded head, not a specifically BCA supplied P, ECO, PECO or BP anchor. Easy mistake to make but watch your terminology as it can lead to confusion.
Should the TC team wish to have some properly tested anchors installed, they only have to contact the DCA and make a case for it.

Offline Simon Wilson

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Re: DCA and the BCA anchoring scheme
« Reply #3 on: February 17, 2019, 05:02:48 pm »
Another point you might like to dwell on is that it is the policy of the BCA Equipment & Techniques Committee not to test bolts after they have been installed. DCA has always disagreed with this policy on the grounds that it is possible to get an incorrect resin mix and consequently Hydrajaws tests are carried out to EN959 subsequent to all bolt installations within their remit..

If the DCA disagree the BCA E&T Committee would it not be a good idea for the DCA to take part in the E&T and talk about it?

The CNCC would have tested some anchors in situ if we had been able to get the use of a Hydrajaws and have requested many times to have one of the three BCA Hydrajaws made available to us.

Offline bobdearman

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Re: DCA and the BCA anchoring scheme
« Reply #4 on: February 17, 2019, 05:38:00 pm »
In reply to the previous post DCA backed out of the E&T Commitee because it was getting increasingly painful bashing our heads against a brick wall with certin disruptive factions. At the time CNCC did exactly the same. Reading through these responses it appears that some of them are still around. We've got a really good system for bolt installation in the Peak District and there's no good reason to change it. As for CNCC not having a Hydrajaws they should go and rattle BCA's cage again to get a fourth.

Offline Simon Wilson

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Re: DCA and the BCA anchoring scheme
« Reply #5 on: February 18, 2019, 04:01:41 pm »
Another point you might like to dwell on is that it is the policy of the BCA Equipment & Techniques Committee not to test bolts after they have been installed. DCA has always disagreed with this policy on the grounds that it is possible to get an incorrect resin mix and consequently Hydrajaws tests are carried out to EN959 subsequent to all bolt installations within their remit..

Bob, as you know the BCA does not dictate to regional councils. The regional councils choose to take part in the E&T, or not to take part in the case of the DCA. The CNCC choose to comply with the BCA Anchor Policy. The Anchor Policy makes no mention of testing of installed anchors.

If the DCA choose to have a policy under which they test every anchor they install they can do that and be in compliance with the BCA Anchor Policy. I am aware that the E&T abandoned it as a requirement a long time ago, shortly after the start of the anchor scheme. The DCA can have a policy which varies from the BCA policy without any disagreement.

If I asked the installers to go back down Quaking Pot with a Hydrajaws they would wet themselves laughing. The CNCC does not require the testing of installed anchors but we would like to have the option of testing. One of the installers did want to test an anchor after installation and I made enquiries about borrowing a Hydrajaws. I know the DCA are holding one of the BCA Hydrajaws and I think the other two are gathering dust somewhere.

Offline MarkS

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Re: DCA and the BCA anchoring scheme
« Reply #6 on: February 19, 2019, 07:52:55 am »
[Sorry this is continuing off topic, but it is relevant to several of the replies]

Simon, I can arrange for you to use one of the BCA Hydrajaws Pull Tester. It is my fault if you thought one hasn't been available recently.

More generally, I think the more the different regions engage with the BCA E&T group the better. As Simon rightly says, the BCA do not dictate to regional councils, but try and coordinate a scheme that generally provides consistency to cavers across the country. An element of variation (such as one or more regional councils choosing to test every anchor after installation) should not necessarily be a barrier to any region being involved in the scheme.

If there is a feeling that it isn't possible to make progress with the BCA E&T group, please just let me know. I expect it is something that we can resolve. As a relative newcomer to the E&T Committee I am unaware of some of the issues from the past, but I think it is in the interests of the BCA and of all British cavers that as many regional councils as possible are actively involved in the national scheme.

Mark
(BCA E&T Committee Convenor)

Offline thomasr

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Re: DCA and the BCA anchoring scheme
« Reply #7 on: February 19, 2019, 11:52:51 am »
 HYDRAJAWS  come up on fleabay  at the moment one nearly new showing.  Historic sale price £200-  £ 400

Offline Bob Mehew

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Please see https://ukcaving.com/board/index.php?topic=24709.msg306486#msg306486 for some related information to deformation of 'P' headed (be they Eco or BP) anchors.     

Offline bobdearman

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Just a point which may throw some light on instances of loose ECO and BP anchors. Les Sykes and myself tested a considerable number of BP anchors in Ingleton Quarry and we found that one of the major problems was that the hole had to be meticulously cleaned. Any dust or limestone surry in damp holes had to be cleaned out. I suspect that many of the loose anchors reported may be due to insufficient cleaning. In Derbyshire around 2012 DCA Hydrajaws tested to EN959 over 400 anchors, mainly Eco, some of which had been installed as early as 1994 without a single failure. The 100mm BP Anchors that Les and I tested failed at an extractive force of between 32 & 65kN with the failure mode being substrate failure in virtually every case. Also we noted that even when the rock was breaking up and the anchor was extracted to half its length they were still showing approx. 20kN on the gauge. We also noted that the Allgrip KMR resin gave marginally higher extractive forces that the Fischer FIS V styrene free resin. I am of the opinion that the BP anchors with either resin are the strongest available given that substrate failure is almost excusively the result of axial forces. The only way that higher anchor extraction forces could be achieved would be to increase anchor length but given that every other item, i.e. ropes, carabiners, maillons etc in the safety chain would have failed before the anchor what would be the point. 

Offline Simon Wilson

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Just a point which may throw some light on instances of loose ECO and BP anchors. ...

Loose BP anchors? Have some BP anchors come loose?

... Les Sykes and myself tested a considerable number of BP anchors in Ingleton Quarry and we found that one of the major problems was that the hole had to be meticulously cleaned. Any dust or limestone surry in damp holes had to be cleaned out. I suspect that many of the loose anchors reported may be due to insufficient cleaning. In Derbyshire around 2012 DCA Hydrajaws tested to EN959 over 400 anchors, mainly Eco, some of which had been installed as early as 1994 without a single failure. The 100mm BP Anchors that Les and I tested failed at an extractive force of between 32 & 65kN with the failure mode being substrate failure in virtually every case. Also we noted that even when the rock was breaking up and the anchor was extracted to half its length they were still showing approx. 20kN on the gauge. We also noted that the Allgrip KMR resin gave marginally higher extractive forces that the Fischer FIS V styrene free resin. I am of the opinion that the BP anchors with either resin are the strongest available given that substrate failure is almost excusively the result of axial forces. The only way that higher anchor extraction forces could be achieved would be to increase anchor length but given that every other item, i.e. ropes, carabiners, maillons etc in the safety chain would have failed before the anchor what would be the point. 

The DMM Eco Hanger is fairly easy to remove without damaging the rock but it does use rather a large hole. I wanted to make a hanger which was more 'Eco' than the Eco Hanger.

I set out to make an anchor which could be removed without damaging the rock and which used the smallest possible hole. They need to be removable because we don't know how the resin will deteriorate and over what timescale. At a rough guess we have over a hundred loose anchors in the CNCC region and it is increasing.

Having looked at all the other designs I knew that the Petzl Colinox was quite good but it had two things wrong. It's too short and it loads the rock near the surface. When you try to pull it out the rock always breaks. My anchor needed to be longer and load the rock at the bottom of the hole. I decided to aim for an extraction force of 35kN which is comfortably over the EN or UIAA standard but not too high. Any higher than that and I thought it would be too difficult to pull out and had the risk of breaking the rock.

When prototypes where taking around 44kN to pull out I went down in size and moved the teeth further down. The final design uses a 12mm hole 90mm deep. Over a sample of 30 tested the maximum extraction force was 36.95kN and the minimum was 35.96kN. The reason why the results are so consistent is that the resin is contained deep in the hole and loaded evenly by the tapers on the teeth.

Most people don't appreciate the sophistication of the IC design which I thought about for over thirty years ever since I first saw a DMM Eco Hanger and thought it could easily be improved upon. Unfortunately the IC anchor will never be available to be used outside the CNCC region. The entire stock is the property of the CNCC and no more will ever be made by me because they are too time consuming to make. It's been a labour of love.
« Last Edit: February 20, 2019, 05:17:46 pm by Simon Wilson »

Offline bobdearman

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No, we have never had a loose BP anchor.

Offline andrewmc

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Just a point which may throw some light on instances of loose ECO and BP anchors. Les Sykes and myself tested a considerable number of BP anchors in Ingleton Quarry and we found that one of the major problems was that the hole had to be meticulously cleaned. Any dust or limestone surry in damp holes had to be cleaned out. I suspect that many of the loose anchors reported may be due to insufficient cleaning.

I think Jim Titt (who makes them) recommends a wire brush and a mechanical blower (the one he sells is for inflating balloons, but works...). Obviously in climbing, holes are normally dry which makes things easier.
What is the standard installation practice for BCA installers?

Offline Simon Wilson

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Just a point which may throw some light on instances of loose ECO and BP anchors. Les Sykes and myself tested a considerable number of BP anchors in Ingleton Quarry and we found that one of the major problems was that the hole had to be meticulously cleaned. Any dust or limestone surry in damp holes had to be cleaned out. I suspect that many of the loose anchors reported may be due to insufficient cleaning.

I think Jim Titt (who makes them) recommends a wire brush and a mechanical blower (the one he sells is for inflating balloons, but works...). Obviously in climbing, holes are normally dry which makes things easier.
What is the standard installation practice for BCA installers?

The regional councils are not subordinate to the BCA. The regional councils can set standards for anchor installation but are not obliged to follow the BCA. The regional councils come together at the E&T to discuss matters and usually come to a concensus. The BCA sometimes issue guidlines. That's sort of how it works but nothing is set in stone and it's all very friendly and low key in my experience. The BCA has no standard for hole cleaning.

One thing the BCA does nationally is provide insurance and that is one area in which the regional councils have to comply with following the requirements.

The CNCC uses the IC anchor and as the designer and tester of the IC anchor I have set a standard for hole cleaning. When I was designing the anchor I experimented with hole cleaning and found that water was more effective than air. Because northern English caves are often wet air cleaning would often be a problem. Water cleaning was decided at an early stage and testing has only ever been done with water-cleaned holes. Because of that installation must only be done using water cleaning.

We aslo use nylon brushes. Wire brushes should not be used because all of the steel brushes I have seen have been carbon steel. You would not want to introduce carbon steel fragments into the hole which would then rust.