UKC

Friday afternoon musing -

When abseiling I usually go with the commonly taught extended abseil: 120cm dyneema sling girth hitched through tie-in loops or around belay loop, overhand knot 20-30cm out for locking krab and belay plate, then a further locking krab for clipping into the anchor. Usually add a second overhand knot about 2/3 of the way along to give some options for clipping in a bit closer to the anchor.

I do find that the overhands can be a bit of a pain to untie after being weighted.

Are there any common alternatives that people have used instead of overhands? I imagine that figure 8s might be easier to untie. Clove hitch the sling around the krab? Feels like it could slip if clove hitching both strands of the sling into the narrow end of a krab.

The overhand option is fine and I'll continue using it, but just wondering if there are any little hacks people know of to facilitate untying.

Get one of the edelrid aramid slings, they're ideal for this. Really good for threads too.

Dunno about making the knots easier to untie, but if that much of an issue could buy a dedicated PAS? Either the sewn link sling type, or adjustable ones?    

You could just use a long and short sling or a stitched daisy-chain type sling, ditch the knots.

I'd avoid knotting slings wherever possible, getting loaded knots out is always a pain. I suppose if it were something you were planning to have to do you could put a tapered metal pin into the knot before loading it, knock it out later to free up some movement. Or buy a marline spike and try not to stab yourself with it.

I just abbed off my belay loop, never liked or bothered with any extension.

jk

Yeah good point, I have one of those. I can see they'd be easier to poke back out of the knot due to the stiffness.

I did hear some concern that they might cut belay loops if loaded when larks footed directly around them, although I don't know if it was ever definitively confirmed and I do find it a bit hard to believe (and/or if you generated enough force for that to happen then you have bigger problems), but I probably ought to get more into the habit of larks footing through both tie in points anyway which should mitigate that issue.

Edit: I'm also considering using a 120cm beal dynaloop for this as well, a bit heavier but it's going to be easier to unknot, and it's dynamic which is nice whilst still being able to be used as a sling unlike a dedicated dynamic lanyard.

Yes it's a fair point, or one of the connect adjusts (where it does seem to be common practice to clove hitch the belay device carabiner part way along the lanyard), but I do like stuff that has multi-use where possible so something I can continue to use as a sling is preferable.

Yes, I have thought about using e.g. a short and medium sling for this, but it does feel like a bit of a faff and I don't know what else I'd use a 30cm sling for (not that they weigh anything). I guess could rig it as a shorter alpine draw. Not a fan of carrying something to block the knot or getting anything spiky near a sling though.

Just clip behind the knot so it's not loaded directly, or double the sling up before clipping it. 

Block the knot, do you mean my tapered pin suggestion? Definitely 4/5ths jest, it is pretty impractical overkill given your other better options.

It's the only way to get into really tight knots, you won't be strong enough to do the sling any harm with a smooth spike but you could do yourself a real mischief!

jk

I do sometimes use an alpine butterfly instead of the overhand, which seems to work nicely. You just have to adjust the tying method slightly to easily make a long enough loop.

I'd second the Amarid. If I extend the plate, though, I usually use a halved 60cm sling, simply threaded through my belay loop with both ends clipped. If I need to clip into something, I'll use a second sling, usually a 120cm. Otherwise, unless I have a heavy sack, I ignore the advice to extend my plate because I keep my prussiks short and clipped to my leg loop and I think there are arguments against always extending (e.g. adding in another point of possible failure). A final option is to tie an overhand on a bight and clip your plate into that, as you can then usually roll the knot off the end of the bight a bit more easily. I wouldn't use a PAS, daisy chain or expensive Petzl adjusty thing for trad because I wouldn't want to look like a complete punter, carrying the kitchen sink around. Hope that helps!

I only bother to extend if I am abseiling with a haulbag when I put myself on an short extension and the bag on a slightly longer one.  I tend to use a PAS or daisy chain rather than tying knots in a sling.

Personally, I just put the plate and krab on my belay loop and clip in as necessary (a petzl wotsit in winter or a just a sling).  Apparently, whilst I may be trusted to catch/lower a partner in this configuration, I cannot be trusted to lower myself and I'm not entirely sure why this should be.  The back up prusik goes on a leg loop and right next to my hand, and has been proven to work - I engaged idiot mode one day when an icicle broke off and I went for a substantial swing and managed to take the wrong hand off to stop myself smashing my face in - the unkind would say that with that sort of mental processing power available, no harm would have come from a smart blow to the head....

I clove hitch the descent device crab into the sling, as suggested by some Guides.  It's adjustable and more easily releasable than an overhand.  And judging by how tight it gets when weighted, there's zero chance of any slippage with just body weight.

I tend to use two easier to untie options if attaching a sling to a harness. Usually for shunting, multi pitch abseiling or aiding.

Double threaded then overhand in all four strands, (can do two different lengths if required in the single loop ends.)

Single end threaded and tie with a bowline on bight.

Both these methods mean you can follow the rope  tie in path, keeps the belay loop clear for other weighings.

FWIW (99% of times ) I  abseil off the belay loop with back up when appropriate on one leg loop.

I find them worryingly skinny, even though I know intellectually that they're extremely strong. And I'm never really sure how the ends are joined under the shrouded section. Abseiling can often feel pretty precarious tbh and so for an extender I'd always go for a chunky 12ish mm sling with a bar tack that I can see. Clearly I'm a scaredey but whatever.

I tend to larks foot one end of a 60cm sling (normally nylon) to my belay loop then basket hitch that (just pass it through) to the belay device's screw-gate before clipping the other end back to the belay loop with another screw-gate. If  This has the bonus of no knotted slings to deal with but adds 1 link to the safety chain (a screwgate) . At other times I might just carefully use a daisy chain for this as it doubles up as a lanyard too.

A bowline works brilliantly here.  I have used it since I was shown this:

https://www.alpinesavvy.com/blog/double-loop-bowline-for-a-rappel-tether

I've never seen any advantage in extending an abseil for personal use. Just make sure the prusik attached to your legloop is short enough (some people seem to like long prusiks and then have to do silly things like extending the abseil as a result.) I've abseiled innumerable times with all sorts of devices, with massive haul bags hanging from the same belay loop, and on all sorts of different ropes, and not once have I ever thought it would have been a good idea to have extended the abseil. Seems to me that extending abseils is something that probably has some use when teaching groups of people who can't be relied upon to keep hair and clothing out of the way of the plate, but has little advantage for experienced climbers.

I teach to extend the ab.

Even with a short prusik on a leg loop it’s really easy to get the prusik to touch the belay device and therefore release.

If I was hit by a rock, slip or whatever and twisted a little, it’s pretty easy to see how the prusik could touch.

Likely? Probably not but certainly possible. 

I don’t really see any disadvantage to extending the device so that’s what I normally use myself.

One advantage in extending the abseil device is speed on multiple abseils.  If its extended you can both go on the rope at the same time and the second person is ready to go as soon as the rope is slack.  If the device isn't extended the second person gets pulled around uncomfortably.  Although this only saves a few seconds it makes a difference if you are doing 20 abseils.  

I'm not too sure that this method of extending your abseil - knotting a sling - is all that commonly taught, is it? As you're finding, the knots will be a bugger to undo.

On a short abseil where I think there is little chance of anything untoward happening, I likely won't bother extending the plate at all.

If I think there's a non negligible chance of becoming inverted (ie rockfall hitting me, loosing my footing, or if I'm carrying a heavy rucksack) then I'll extend it for the reason Jez gives: if the Prusik reaches the plate then it'll release and that's game over.  But I'd do this just by doubling a sling over through my belay loop, no knots.  That way there's nothing to untie.

It's worth mentioning that extending the abseil increases the chances of hair getting caught up, as it puts the plate right by your face (unless you are extending it a very long way).

If I need to clip into an anchor, that's a different job to extending the abseil and I'll use something else for that - a separate sling, or a bit of rope fashioned into a PAS.

Wow, 3 dislikes so far for responding to the OP and sharing my  method which sounds the same as many of the others. I know the unhelpful UKC tradition of trolling anyone who mentions them but seen as this is my abseiling system and quite important, if there's a glaringly obvious problem with my system then I'd love some constructive feedback...

If you've larks footed a sling to your belay loop to use as a tether you might as well stick your belay plate on it too. If you've got a pivot or a Reverso it's also really quick to switch from abseiling to ascending the rope - all you have to do is clip the shackle back to your belay loop, no need to detach it from the rope.

If I'm doing a simple single pitch ab from a big ledge down to the ground I won't bother extending but anything more complicated it's quicker and easier to use a tether. A 120cm aramid sling with an overhand about 30cm away from your harness is perfect and the knots come undone really easily even after bouncing around on it.

Stupid question I'm sure, but...how do you finish tying that without being a contortionist? I've only ever used a bowline on the bight to tie into the middle of a rope, but I can't see how it's possible to tie it around the tie-in points of a harness without stepping through the loop?

Hi Jez

I know we've debated this before, but I'm replying again because I've had some more occasions on which to test this, and because in the quote above you imply that the prusik releasing itself is an inevitable consequence of it touching the device, which couldn't be further from my own experience.

With a sufficiently short prusik I find it needs a pretty unusual contortion to get the prusik to touch, but even then I can't get the prusik to release itself. I've tried this with various combinations of harnesses and ropes, with single and double ropes, modelling unconscious positions with one leg stuck vertically upwards, wriggling around in a variety of highly unlikely positions ... the only common factor being the short prusik. By no effort can I get the prusik to release itself - not ever.

Perhaps this is just a question of how short is short? If you lived just down the road from me, I'd pop down and show you one of my short prusik loops and how I attach it. If I get time, I'll repeat the above experiments and make some video clips to post here.

Donnae fret: it's probably just some dogmatic people on MT courses plus a few old hacks who think you're "not a real man" unless you create friction in an abseil by wrapping the rope three times around your testicles.

 if the Prusik reaches the plate then it'll release and that's game over. 

Yes, that's the theory: everyone says that the release will follow the touching, sure as night follows day - but will it actually do this in practice, though? See my reply to Jez above.

I demo this almost weekly. Give yourself a twist and lift your leg up a bit. When they touch in my demos, the prusik never jams in to the device, it always releases.

This is my personal repeated experience.

See the alpine savvy link at 1749 Saturday.

Works well with a double 120 sling.

(Not easy to do a link with my phone.)

Please post video clips, sounds like a laugh.

Yes. I demo this above a big mat quite regularly when I'm teaching.  If you allow yourself to fully invert the prusik easily reaches the plate, and then it completely lets go.

I have also tried to get the prussic to touch the belay device and failed.

Maybe it is down to how tall you are and how snug you fit your harness, I like to make sure that my waist belt sits above my hips and keep my leg loops tight.  It may also help that I refuse to use harnesses with zip lock buckles as I find them prone to slackening off during long climbs and especially if a prussik is attached to a legloop.

As previously mentioned use an Edelrid Aramid sling and you'll never have any major problems with the overhand knots

Additionally if you tie the 120cm sling to your harness using a double bowline around your tie-in points (rather than the girth-hitch) the sling then ends up slightly shorter, near the perfect length, so the second overhand you mention then isn't required. Once you've worked out how to do it, it takes literally 2 seconds longer than the girth hitch. 

(Someone linked a photo of the knot in question but using it around the belay loop which was rather odd.) 

A figure of 8 might be slightly easier to untie than an overhand after loading, but will use slightly more sling (i.e. very slightly shorter)

A figure of 9 (fig 8 with extra twist) is slightly easier again to untie after loading but will use slightly more sling than the 8, so again a little shorter again. Also it will look scruffy and someone not knowing what it is might assume you don't know how to correctly tie a fig 8.

Try them and see what sling length you end up with, use whichever you find is easiest and still giving acceptable length. How much the knot reduces depends on the sling, very wide flat tape will be reduced more than 8mm dynatec (for example). Try it and see with *your* sling

Is this maybe a question of what type of prusik you're trying?

Like I said in my previous post, I've experimented with this extensively, twisting, leg up, and many other bodily contortions besides. With an effort I can get the prusik to touch the device, but it still won't release. Then there must be a difference in the way I'm doing it, to get such a completely opposite result in practice - in the prusik length, no. of wraps, etc. There aren't so many variables - it should be possible to get to the bottom of this, one would think?

Edit .... are you demoing this with the standard length prusik you use for other applications? If so, I'm not surprised that you get a different result to me. I carry a dedicated short prusik for leg-loop back up, plus (usually) a longer prusik for other uses.

Possibly. For leg-loop backup for abseils I do whatever keeps the knot really close to the harness. Standard French prusik with 3-4 wraps does the job if the loop is sufficiently short, but if there's a little extra slack to use up I sometimes twist one end over the other before clipping.

Years ago we were with a bunch of students cleaning up some new routes in NZ. At that stage having the prusik on the leg loop was the standard unlike now. One student after a break (pee?) went back to his cleaning and his leg buckle with the prusik came undone. Surprisingly the only thing stopping that from being a serious incident was that his prusik became jammed into his ATC. Definitely a lot of learning came out of that!! including a back up clove, reinforcing checks AND just taking the leg loop out of consideration. I really can't see why one would continue using a leg loop prusik back up especially when one of the benefits of the extension is the leash. I tend to use a purcell for this. I also learnt the hard way that doing a diagonal abseil on less than vertical terrain in a rain storm with wet ropes with a leg loop back up is really really annoying.

Yes, it's standard practice in North America to extend the belay device and attach the prusik to the belay loop.  Andy Kirkpatrick has mentioned that at least one climber has been saved by this arrangement when they've made a mistake and were left hanging from the prusik.  Before you say you triple check everything, I was at a crag where a very experienced climber only clipped one rope on rappel and was killed.

Just lift your leg up.

I demo this with various harnesses, all fitted well, with various prusik cords.

I’m out of this post though, there’s only so much talking about wraps of string that I can do before I feel the need to have a word with myself…!

I use an overhand on a bight, creating a small isolated loop in the middle of my 120cm sling and clip my belay krab into that loop. I find that unties easier than a standard overhand knot. 

You make it sound so simple but I've tried really hard and my leg just doesn't go that high. 

I cannot get the prussik to contact the plate, iit is not going to happen unless I dislocate my hip

I guess that different people come in different sizes and shapes, use different harnesses and adjust those harnesses differently.

If I remember correctly the movement away from the leg loop actually started in the UK. It was shown if someone was unconscious that they would arch back and the hip with the leg prusik would roll up and, in most cases, contact the belay plate.

Its a pretty different scenario, though, cleaning routes with hands off the prusik to just abseiling where its only a an emergency back up.

Negatives: one extra screwgate needed, larks foot around belay loop causing increased abrasion, classic aid climbing daisies normally not fall resistant (unless you use a PAS made from short, fully rated loops that can double as a classic daisy),...

That said, if I bother to extend I put my ATC into a the first or second loop of my Metolius PAS, leaving the end free to clip into the next abseil bolt.

Yes I also larks foot that thing to my belay loop, but I tend to wear out the leg loops of my harnesses much more quickly so that has never been an issue. I have never retired a harness because of belay loop wear and tear!

But there seems little point in having an emergency backup that could be rendered useless if unconscious, if one of the emergencies you're backing-up against is being rendered unconscious by rockfall.

Thanks for taking the time to reply.

like I pointed out myself...

Not significant in this instance I don't think unless you are walking around a lot with it like this (but even then more of an issue if it was your tie in points instead of your belay loop because it saws). It's pretty standard to larks foot stuff to your harness isn't it? Slings, lanyards, PAS, via ferrata kits etc. Without knotting it, you can't have it both ways with a simple sling though, you either hitch it to your harness directly or you accept the extra locker in the chain. 

A sling isn't "fall resistant" either (a daisy is just a sling with loops stitched in). Neither though is your PAS AFAIK, as those fully rated loops are still not dynamic. But that's OK, because we're not falling on it, remaining below the anchors and avoiding any slack... As long as you are not clipping 2 loops incorrectly (dangerous failure mode), the pockets on a daisy can easily take the forces from an abseil can't they?

OK, same as me then... and now it's not an issue... you seem somewhat torn...

The probability of a rock knocking you out AND your leg loop undoing seem pretty OK to me.  Either of those events on their own are very unlikely. 

If the main cause of prusik failure is inverting after being rendered unconscious, then the combination seems more likely to me than I'd like to bet my life on, especially when extending the belay device has zero convenience cost and zero additional gear requirements beyond what I'm already carrying. The prusik, for me, is there primarily in case such a thing happens, because I otherwise trust myself not to let go of the rope and if I stop deliberately I always take a few turns around my leg anyway.

Don't get me wrong, I still often ab wit the prusik on my leg loop (or sometimes without a prusik at all) for convenience, but I probably wouldn't choose to do it on a long descent, in the mountains or at a crag with a loose top-out. It's personal choice though.

Why not just use a 600mm sling, you carry it over your shoulder, you can use that direct, larks footed, or doubled over if you need to. No need for knots.

You can used it to extend quickdraws or to equalise belays, they come in very useful and cosy under £5, what's not to like?

This works well for extending when abseiling a single pitch (though I wouldn't normally bother in this case, like most people on this thread), but the advantage of a knotted 120cm sling is that you can put the device halfway up, and then use the end to clip into the anchors after each abseil.

There's also the now frowned ultra oldskool approach of keeping the belay/abseil device on the harness abseil loop but using prussik  above the belay device, obviously it needs to have enough turns and to be releasable after loading (like french not standard). It does have advantages of making passing a knot (if rope damage knotted out) and is generally easier, simpler, nicer to use.

Providing the limitations can be managed, it's another tool in the toolbox. I still use this approach sometimes

If you do it a lot why not get a short sling for the purpose and separate cow's tail (rope or sling) for clipping?