which carabiners for anchors

[alanw]

Many years ago I was present, IIRC at the BMC premises in South Manchester, when Neville McMillan demonstrated how little force is required on a misaligned figure-of-eight to break the gate-locking sleeve and open the karabiner. I'd be interested to know whether a similar misalignment can happen with e.g. a P hanger.

https://www.c2safety.com/wp-content/uploads/2020/05/karabiner_breakings_with_figure8.pdf

 

[andrewmcleod]

Many years ago I was present, IIRC at the BMC premises in South Manchester, when Neville McMillan demonstrated how little force is required on a misaligned figure-of-eight to break the gate-locking sleeve and open the karabiner. I'd be interested to know whether a similar misalignment can happen with e.g. a P hanger.

https://www.c2safety.com/wp-content/uploads/2020/05/karabiner_breakings_with_figure8.pdf

Almost certainly, I suspect, for some combination of P-bolts and carabiners. Gate/nose loading is scary (and can easily remove the nose of the carabiner as well)...

 

[mikem]

I don't remember entanglements being a reason the HSE accepted the outdoor pursuits industry could use a single rope, but there were many good reasons. I sat on a HSE work at height committee when the 2007 amendment to the Work at Height Regs. came out and the person who wrote it (who headed up our committee) made it very clear that if the failure of a single point of attachment resulted in a serious accident or worse, the HSE would throw the book at them and likely result in a much smaller outdoor pursuits industry due to the likely significantly increased insurance premiums that would follow.

It was certainly an issue that BMC foresaw in 2005:
"For example, to make a multi-pitch abseil off a route as per the regulations would require at least four ropes. Leading to confusion, tangles, and time implications in the short term, and over a longer period, a deep confusion in the sport as what was actually the best technique in the first place. In fact the whole situation was getting pretty ironic. The rope access and construction industry had originally borrowed techniques and equipment from climbing, adapting them for their own needs. And now these very things were about to be forced back on climbers, without anyone ever asking for it."

Safety at work

www.thebmc.co.uk

 

[Mark Wright]

This specific case does not pose a life threatening situation. Because if a climber below is already on the rope - there is no way the loaded snap gate can unclip. And if he isn't - then in the worst case he is going to "skip" a re-belay and climb towards the next one.

If there is already somebody on the rope below the re-belay then there is little likelihood of the carabiner becoming abnormally loaded and unclipping itself.

Having two people on the same rope at the same time is not normal practice, though I have climbed out of Rowter Hole with Pitlamp and Graham Proudlove all on the same rope back in the 80’s.

Top and bottom cavers climbing together and then resting while the middle caver climbed. I remember it being really awkward for the top two cavers getting off at the top with another persons weight on the rope.

In some cases an abnormally loaded carabiner, whether single, double or triple action, can brake with only a single persons weight hanging from it. There is a video on here somewhere showing how easily this could happen.

Mark

 

[mikem]

Many years ago I was present, IIRC at the BMC premises in South Manchester, when Neville McMillan demonstrated how little force is required on a misaligned figure-of-eight to break the gate-locking sleeve and open the karabiner. I'd be interested to know whether a similar misalignment can happen with e.g. a P hanger.

It's very similar to the mechanism for a krab unclipping itself from a bolt on the floor (which I currently can't find on BCA site or here), but think it would be harder to replicate with a wall or ceiling anchor as gravity means that the krab wants to hang down.

 

[mikem]

If there is already somebody on the rope below the re-belay then there is little likelihood of the carabiner becoming abnormally loaded and unclipping itself.

I think the most likely time for krabs to become disorientated is when the person is moving past the anchor above, thus lifting their rope & the lower anchor, so there is more chance of somebody being on the lower rope at that point.

 

[paul]

It's very similar to the mechanism for a krab unclipping itself from a bolt on the floor (which I currently can't find on BCA site or here), but think it would be harder to replicate with a wall or ceiling anchor as gravity means that the krab wants to hang down.

Are you thinking of the example on this CNCC page (https://cncc.org.uk/fixed-aids/anchor-safety/) 'CNCC Anchor Warning'?

 

[mikem]

Thanks, that is the one - you'd be very unlucky to fall on a locking krab at that exact moment though.

 

[mikem]

It is an occasion where a freely rotating hanger on the bolt might be advantageous.

Maillons are slow & fiddly but can be undone with a spanner, or your stop, when jammed. Snaplinks are quick & easy, but need to keep an eye on their position.

So, if a locking krab jams what are your options? - carry pliers, unthread the knot, or cut the cowstail. You can then tie another krab in (or use a bit of your SRT rope if not long enough to do that). If you don't have a knife then another length of rope can be used to cut a taut section (narrower diameter is more effective).

If it's part of the rigging then you could leave everything to recover later, otherwise your options are the same as for the cowstail (but with a whole load more rope to pull through the knot).

 

[Fjell]

I find these twist maillons to be quite effective for single P-bolt rebelays. Unfortunately they only make them them in 8mm rather than 7mm, but otherwise I often end up with two krabs. Puts rope at correct orientation and is significantly more robust to being misaligned (and is harder to misalign). Stronger than krab. Much easier to clip too.


https://www.v12outdoor.com/media/ca...6e95/6/5/65DABB92D8B3BAD9DAB0CEABC8B1BC97.jpg

 

[andrewmcleod]

It is an occasion where a freely rotating hanger on the bolt might be advantageous.

Maillons are slow & fiddly but can be undone with a spanner, or your stop, when jammed. Snaplinks are quick & easy, but need to keep an eye on their position.

So, if a locking krab jams what are your options? - carry pliers, unthread the knot, or cut the cowstail. You can then tie another krab in (or use a bit of your SRT rope if not long enough to do that). If you don't have a knife then another length of rope can be used to cut a taut section (narrower diameter is more effective).

If it's part of the rigging then you could leave everything to recover later, otherwise your options are the same as for the cowstail (but with a whole load more rope to pull through the knot).

I'd almost certainly end up having to cut my cowstail if I got my one of my twistlocks jammed somewhere I couldn't otherwise release it i.e. tied into an anchor, or into fixed rigging I couldn't/didn't want to untie/retie. It would be quite reasonable for the 'retie your cowstails' brigade to engage 'smug mode' at this point. I'd have no significant fears about opening a rigging carabiner to get my stuck carabiner out provided I did it carefully and was still backed up by the rope above.

Mostly I just give carabiners them a good whack when they get jammed (usually due to a single piece of grit in the thread, I suspect. It's important that your carabiners know who's boss...

That would be a good time to have a 'third' cowstail (i.e. using a carabiner to attach your hand ascender/footloop to your safety loop) and go Alpine/French style...

PS top tip - if while down a cave using an _old_ screwgate carabiner and it's jammed, try loading it with your body weight as the older carabiners don't have an internal 'stop' and tighten up against the gate. When you load the carabiner, you stretch it slightly, letting you tighten it up slightly, and then when the weight is released it jams up and you can't free it. If you have one of these carabiners, some people will tell you you need to loosen them off a quarter turn after doing them up, but much better (and more reliable and therefore safer in the long run) is to throw that old crap away and buy a new carabiner (even the cheapest, nastiest screwgate).

Even with new screwgates that do have the internal 'stop', sometimes loading them will help get them undone when they jam (I assume just because the stretch moves things slightly internally).

 

[aricooperdavis]

I personally don't like using a screwgate to attach my hand ascender to its tether. If you orient the crab so that the screw can't work its way unscrewed under gravity then it's the wrong way around to use as a third cowstail. You could spin it around if you want to use it as a third cowstail, but you have to be able to get the gate either through the ascender or through the knot.

I do attach my footloop to my hand ascender using a snapgate, though, because I find an independent footloop useful for fiddly rigging and bolting, and I can always clip it through the maillon on the hand ascender tether to make a makeshift third cowstail if needs be.

 

[paul]

So, if a locking krab jams what are your options? - carry pliers, unthread the knot, or cut the cowstail. You can then tie another krab in (or use a bit of your SRT rope if not long enough to do that). If you don't have a knife then another length of rope can be used to cut a taut section (narrower diameter is more effective).

Over the years I have freed a locking krab many times by either wrapping a short length of tape (part of a sling, chest harness or whatever) around the screwed sleeve to provide leverage or just knocking the screwed sleeve in the right direction with another krab (assuming just weighting the krab doesn't unjam the sleeve.).

 

[mikem]

Indeed, I've never had to resort to further methods, but it's what people seem to be concerned about.

 

[IanWalker]

Wiregate rigging (in photos)

Sell Gill Holes (Dry Way) – Monday 9th January 2023

On a very wet start to the year so Chris and Geoff Dudman found a relatively dry day to get down this famous hole. Enjoy their photos!

whiterosepotholeclub.wordpress.com

 

[andrewmcleod]

Wiregate rigging (in photos)

Sell Gill Holes (Dry Way) – Monday 9th January 2023

On a very wet start to the year so Chris and Geoff Dudman found a relatively dry day to get down this famous hole. Enjoy their photos!

whiterosepotholeclub.wordpress.com

You should have used clove hitches on the traverse carabiners to really wind up the people who think they know better

 

[Mark Wright]

I personally don't like using a screwgate to attach my hand ascender to its tether. If you orient the crab so that the screw can't work its way unscrewed under gravity then it's the wrong way around to use as a third cowstail. You could spin it around if you want to use it as a third cowstail, but you have to be able to get the gate either through the ascender or through the knot.

I do attach my footloop to my hand ascender using a snapgate, though, because I find an independent footloop useful for fiddly rigging and bolting, and I can always clip it through the maillon on the hand ascender tether to make a makeshift third cowstail if needs be.

Is a vibration induced unscrewing of your top jammer screw gate really such an issue? It is after all in front of your face and easy to spot.

The main issue is when screw gates are used for main rigging attachments where they can’t be examined before you start climbing up the rope. It’s always a good idea to turn them upside down in these situations.

As for the gates jamming up, I used to see this happening nearly every day during over 20 years of rope access training and never once did candidates have to resort to using pliers or any other of the methods described in the various posts above.

Simply applying your body weight to the carabiner would nearly always allow them to be unscrewed. On the rare occasion it didn’t work then a simple body weight bounce on the carabiner always did.

Mark

 

[aricooperdavis]

Is a vibration induced unscrewing of your top jammer screw gate really such an issue? It is after all in front of your face and easy to spot.

Probably not, but I'm lazy and would rather be able to trust that I'm properly attached to my hand ascender without thinking about it. A triple action would solve this problem, but my maillon is smaller, lighter, cheaper, and really not much less versatile (when paired with the crab attaching my footloop to my hand ascender).

 

[Samouse1]

Is a vibration induced unscrewing of your top jammer screw gate really such an issue? It is after all in front of your face

I had an interesting situation once where the undone screw gate I was using on my hand jammer turned itself over and clipped into the top of my croll. Not awful to get out of but was certainly a “what on earth is happening” moment

 

[cap n chris]

Enjoyed viewing the absolutely mahooosive Sell Gill y-hang. I've always just taken a minor Y off the end of the traverse and deviated to get the clean drop, thinking it's significantly easier to rig and negotiate. Horses courses. I vaguely recall a video wot I dun wot might show it. Shall rummage..