• Descent 302 is published on 15 February and it will soon be on its way to our subscribers.

    In the newsdesk, read a review of the underground events at Kendal Mountain Festival, plus tales of cannibalism and the Cavefish Asteroid.

    In regional news, we have three new connections in Ogof Agen Allwedd, a report on the iron mines of Anjou, an extension to Big Sink Cave in the Forest of Dean, a new dig in Yorkshire's Marble Steps Pot, student parties, an obituary for Tony Boycott, a tight find in the Peak District and a discovery in County Kerry with extensive formations.

    Click here for details of this edition

Simpson Chains

To chain or not to chain (that is the question)

  • In favour of chains being fitted to Simpson/Swinsto for pull through

    Votes: 98 89.9%
  • Not in favour of chains being fitted to Simpson/Swinto for pull through

    Votes: 11 10.1%

  • Total voters
    109
Additional anchors have already been installed specifically for pull-throughs.
Thanks. I’m probably just completely blind, but I can’t actually find where Ian writes that this has happened already for the three locations in question

Slit Pot

Linking 2 of the existing anchors here with a chain would provide a single attachment point and allow a clean up of the surplus anchors.

Over the top at Slit Pot

Currently work here has included an extra anchor on the traverse to make it more “sensible” and 2 anchors suitable for a y hang.

Great Aven

The pitch head at the top of the sloping rift which had the most accumulated “Tat” has been rationalised to a TWO anchor pitch head suitable for both styles of rigging.
 
This is what the BMC say:
"Until recently there was no standard for belay sets or components, so purpose-made belays from bolt manufacturers were made from EN959 bolts with additional components obtained from a variety of sources. This changed with the recent update to the EN959 standard, which now includes a standard for those belays which include two bolts linked together, usually by a chain.

Whether bought complete or assembled using components yourself, there are two important rules for belays.
● Always use components made from the same material, otherwise the belay will be subject to a dangerous form of decay called galvanic corrosion. Typically, this means components and bolts which are all made of AISI 316 grade stainless steel.
● All components should be rated as load bearing. A minimum breaking load of 25kN is given in EN959 as a requirement for all components of a belay. This means that any additional components, which may be subjected to wear, are at least as strong as the
anchor bolts in their strongest orientation.

There are a number of different formats and options for lower-offs, and which is best depends on a number of factors.

The simplest format is a pair of belay bolts. These are either resin bolts with a larger eye or expansion bolts fitted with a special belay hanger. Each has enough room to thread a bight of rope through whilst having a karabiner also attached to them and provides a rounded radius which doesn’t damage the rope as the climber is lowered. These have a low visual impact, which is useful for venues where bolting is barely tolerated by the landowner, and they also give the most placement versatility which is important when the rock quality is poor.

On the more popular routes and crags, wear of the lower-off bolts can become a major problem, particularly where bottom-roping is common. In these cases, it is important to have some form of replaceable and hard-wearing component to lower-off from, which when worn can be replaced leaving the bolts themselves intact. Historically climbers have left old karabiners on the bolts, but these rapidly seize up and decay because of galvanic corrosion.

One option, which can also be retro-fitted to existing belay bolts, is to attach a belay ring to each belay anchor using a stainless steel maillon. The rings last for a long time as any wear is evenly distributed as they rotate in use. Thread-lock glue on the maillon prevents casual theft, but still allows removal with a spanner when the ring eventually needs replacing.
Maillons used alone are cheaper, but wear faster and have a tendency to be undone by movement of the rope.

Overall, the ring and maillon arrangement has much to recommend it, but there are two downsides to consider. The most important one is that the rings must be threaded, which requires the climber to untie from the rope. This creates a safety hazard both for novices untrained in how to do this safely, and for experienced climbers who may make an error. Secondly, the rope going through two points tends to cause twisting of the rope, particularly if the belay points are level with each other.

There are other options available which can help solve these problems. Linking the bolts with a chain allows a single point to be used to lower from which prevents twisting of the rope.
Curled metal shapes called rams-horns allow lowering without having to re-thread and untie the rope. Stainless steel karabiners give a good balance of security and ease of use.
Before considering any of these options, bear in mind that they will have some downsides of their own, and often an increased expense."

Untying the rope is not an issue that we have to worry about, but we are concerned with twisting, expense and aesthetics (my highlights). It would be interesting to know if any research has been done into which direction is easier to pull down a rope from the vertical bolt above, horizontal bolt below orientation.
 
Last edited:
Hello all

Firstly we want to say thank you to everyone who has posted above, for your robust discussions about the installation of chains for pull-through on the three sites at Simpson Pot (Slit Pot / Slit Pot bypass and Great Aven). While, of course, UKCaving does not present everyone's opinion, it gives us an important snapshot of different viewpoints. This highlights one of the many values this forum brings to the caving community.

We'd also like to thank IanP for bringing this to CNCC and the work he has put into researching and developing the idea.

The matter was discussed at our meeting on Saturday 26th October, where it had already been very well considered. We noted that several of our Committee had engaged extensively on the matter with those who they represent.

Despite the very different views reflected both on this forum, and at the meeting, the discussion was well-natured and interesting.

We will be putting together a report on this subject for a future newsletter (hopefully our next one, due before Christmas), and of course, the full details of the meeting will be in our draft minutes which will be published before then.

In summary, there was strong support for installation of these chains (12 votes in favour, 3 abstentions, 0 against).

That doesn't mean you will see chains appearing immediately: Firstly, our installers need to complete the re-anchoring work to replace the loose and/or worn anchors at Slit Pot. Secondly, the meeting raised some important points for consideration, particular around the technical specification of the chains. These considerations are now going to be taken on board during the final implementation. Thirdly, we want to ensure that installation coincides with clear labelling of these on our topo, publication of training resources on how to rig pull-throughs using the new system, and how to perform pre-use safety inspections of the new installations. Finally, the proposal gave a mandate to install chains at up to the three sites. This wording gives freedom to the team to perhaps reconsider any of the three locations if there are changes in circumstances.

We have identified that there is support for the chains. We will now focus on getting their implementation right.

Thank you all for your engagement.
 
May I suggest liaison with DCA regarding this. I believe they originally used chain for the Giants Hole Crabwalk, but changed to swagged wire which could be tested and certified before installation. It can also be exchanged for re-testing periodically. This maybe a red herring on my part, but trying to be helpful!
 
May I suggest liaison with DCA regarding this. I believe they originally used chain for the Giants Hole Crabwalk, but changed to swagged wire which could be tested and certified before installation. It can also be exchanged for re-testing periodically. This maybe a red herring on my part, but trying to be helpful!
Ian P had been in touch with me before the debate on here to ask about the chain we used at DCA.
I'm interested in hearing what the CNCC meeting said about the technical specification for the chain.
 
Looks like someone just questioned how they were going to specify it. A chain has more moving parts, so more wear points / checking required, but that may be an advantage in some circumstances as force is spread over whole thing, whilst swaged wires may concentrate all the wear at the ends.
 
Ian P had been in touch with me before the debate on here to ask about the chain we used at DCA.
I'm interested in hearing what the CNCC meeting said about the technical specification for the chain.
Hi Pete

Nothing was specifically said about the technical specification at the meeting, rather a sensible rounded view that this could be handled by myself with input from other suitable people.

Talks are underway and I will definitely be in touch with you in the very near future.

Regards
Ian
 
Back
Top