UKC

Hi, What would your preferred knot to join two ropes together be? For abseiling. And why?

In reply to eivrol:
Overhand with long tails, for reasons very well summed up here: http://www.andy-kirkpatrick.com/articles/view/the_ultimate_abseil_knot

In reply to eivrol:

his has been gone over many times on UKC; good piece about it on Needlesports site

http://www.needlesports.com/catalogue/content.aspx?con_id=75b7be92-45dd-474...

In reply to eivrol:

Whichever of the reliable options you're comfortable with, the technical distinctions get pretty small. Why: because you're the one who'll be hanging from it.

Personally I tie an overhand.
jk

In reply to eivrol:
More info:

http://www.gudelius.de/spst.htm - shows the "Triple T-Overhandknot". Andy K mentions it briefly here:
http://www.andy-kirkpatrick.com/blog/view/edk_question but dismisses it as too complex, and also points out that a figure 8 tied as a Flemish bend is very secure, but doesn't mention its liability to jam.

Overhand is very clearly implicated in a lot of disasters, so be wary of it if planning to use it.

I wondered if there were some other options - there are infinite knots, and thousands of simple knots. After thinking for a while, I propose using the beginning of a double fisherman's knot (so tying one strangle knot around the other rope), and then tying an easy-to-untie stopper in the strangled end. A simple stopper that should be easy enough to untie is the figure 9 knot (which is super easy to tie, if you can tie a fig 8 knot). Unfortunately I have no way to test how this knot combination would perform. I reckon it'd be approximately as strong as a double fishermans, but would be far easier to unitue (untie the stopper, and then pull the loose end through the strangle knot). Stevedore knot (which is to the fig 9 as what the fig 9 is to fig 8) would be another alternative, even easier to untie, but due to its bigger size is also more likely to come undone with cyclic loading.

In reply to SenzuBean:


Where's that then?

Overhand with decent tails is my go to method.

In reply to SenzuBean:






Bloody hell!

Or you could just use an overhand know with long tails like everybody else does!

In reply to eivrol:

As a newcomer to the forum I would advise you to look at the profiles of the people giving advice, just click on the name of the poster.

In reply to Oceanrower:
"Hello, Andy

First of all, sorry about my poor English.

My name is Miguel and I’m a Portuguese climber. I would like congratulation your website and you. I really admire your climbing skills and it’s a pleaser read some articles in some English magazines. You are a reference for all of us…

I’m writing to you because your recent article about THE ULTIMATE ABSEIL KNOT.

During year I used the Simple Overhand Knot to rappel. But one day I almost saw my climbing partner falling because this simple knot. We were trying to open a new winter route in the East face of Cântaro Magro, one of the huge and challenging winter walls of Serra da Estrela, our highest mountain (in Portugal). We climbed all night in bad snow and weather conditions and in the morning we were tired. We 80 meters below the summit we decide come down and trying this climb another day. We began rappelling. One after one, we were closer to the base. In the last rappel, my partner was the first to down. When he was in the middle of the 60 meters rappel I casually look to the knot. What I saw was the ropes sliding into the knot. Scared I put my hands, and try to stop the ropes sliding. Firmly, I put a Prussik Knot holding the two ropes and my partner arrive safely to the ground.

I don’t know what happen, what was the reason. The Knott was well madding but the 8.5mm ropes were very wet.

For me this was very scared and after this, I and my friends never made this rappel knot again.

Last winter to Spanish Climbers died using this knot.

Maybe a will go try the Double Overhand Knot after reading your article.

Thanks to share your experience with all us.

Cheers

Miguel Grillo " - http://www.andy-kirkpatrick.com/articles/view/the_ultimate_abseil_knot

Secondly, I suggested quite an easy knot - it's at least as easy as a double fishermans and IMHO much easier. What's so hard about a strangle knot + fig 9?
To be 100% clear I'm not suggesting anyone _use_ this knot, just to test it in a rig to see how it goes.

In reply to eivrol:

Overhand with longish tails.

In reply to eivrol:

This is going to run and run.....

Overhand with long tails. (But not so long that you can mistake them for the "live" ends and abseil off them.)

In reply to SenzuBean:


This must be why the Americans call it the EURO DEATH KNOT.

Doesn´t stop anybody using it, though: Easy to tie, easy to check, easy to untie even when covered in dirt or ice, unlikely to snag, and, most importantly, unlikely to roll (you can add a snugly tied second overhand as a stopper for peace of mind...).

Do not use a Fig 8, this can roll very easily!

CB

PS: In all fairness, there have been a few deaths indirectly caused by tying the abseil ropes together using an overhand: The tails were left too long, causing the climber to put one of the tails rather than a full length rope strand into their abseil device

In reply to Chris Craggs:

Colin looks happy!

In reply to SenzuBean:

Wow! Despite all of that waffling, I'll stick to my European Death Knot thanks!

In reply to galpinos:


Slightly pensive perhaps


Chris

In reply to SenzuBean:


Such as which?

Your clearly state in your profile that you have almost no climbing experience, yet you seem to spend most of your time on here spouting about absurdly overcomplicated knots as solutions to problems that either aren't problems or are already satisfactorily solved.

The overhand has established itself in the past ten years as clearly the abseil knot of choice. You may wish to consider the possibility that perhaps don't, just yet, know more about this than pretty much every mountaineering and guiding organisation in the world.

In reply to eivrol:

Are people still arguing about this???

In reply to Wide_Mouth_Frog:


Only Senzubean. Other than that, a rare moment of accord from UKC!

In reply to eivrol:

An old classic but still got legs on it by the looks of things.

In reply to AlanLittle:

Climbing experience is not the only way to be proficient with knots mate - secondly if you think a strangle knot or a fig 9 is "absurdly complicated" then you I'll be glad to get a few boy scouts to teach you how to tie both of them.

In reply to eivrol:
Everyone talks about the figure of 8 knot tied with two strands so the knot is loaded sideways.

I am surprised no one mentioned the other kind of figure of 8: http://i.ytimg.com/vi/4PRVLSfJ3LE/hqdefault.jpg . I can't remember its name, but the picture should be enough. More difficult to tie, though seems to be okay to use?

Edit: It's a Flemish knot/Flemish bend.

In reply to SenzuBean:
Can they teach me to do it with hands that are really cold despite being in thick gloves when my goggles are steamed up and I've got a couple more pitches of abseiling to go and I'm knackered after a hard route?

Keep things simple is my advice, but you can use whatever knot you and your partner are happy with.

The rest of us will probably be abbing off an overhand...

(watch you bulky knot doesn't get jammed when your pulling it down)

In reply to eivrol:

Edk,the simplest knot and also the best as I discovered from my hours of internet searching before my first big rappel, I must admit it plays on your mind because it's so simple but I do always back it up

In reply to SenzuBean:


on this forum, for these purposes- you're damn right climbing experience is the only way to be proficient. overhand with long tails.

In reply to tom84:

Reef knot with stoppers. Former is easy to undo; ditto latter as they don't get loaded

In reply to SenzuBean:
I agree, having re-read your knot description it sounds easy enough. Sat in my living room. Now: can your partner reliably double check that you tied it correctly? In the dark, in pouring rain and a howling gale, after you've both been on the go for fifteen hours and are barely conscious?

Next question: supposing I trust your superior theoretical knowledge of knots and believe that your invention won't break. Fine. Nor will a double fisherman, nor will an overhand. Do you actually know why the overhand was universally adopted over the numerous other options? The ease of untying is secondary: it's mainly because it's a very small knot and has a flat side, and is therefore least likely to get stuck somewhere when you pull the ropes. In the dark, in a gale etc.

I'd be entirely willing to believe nobody has ever died as a result of a double fisherman joining abseil ropes *breaking*. I wouldn't be in the least surprised to hear that people have died because of a double fisherman joining abseil ropes getting stuck. I don't see why your bulky contraption would be any less prone to this.

These are things that are relevant to *climbing* and require you know you have some experience of the reality of *climbing* situations, so that you at least understand what the problem is that you are suggesting solutions for. The mechanical properties of knots are a very small part of it.

I would suggest that one can get by as a climber these days with four knots: figure 8, overhand, clove hitch, a prusik variant. (Useful optional extras: munter hitch, butterfly, a bowline variant, double fisherman) And this is a feature not a bug. If everybody relies on a common set of good-enough, easily learned and recognised basics, then the chances of somebody getting something wrong, and their partner failing to spot it - by headtorch, after fifteen hours on the go etc. - are significantly reduced compared to if everybody goes around inventing everything for themselves from first principles.

Your knots-as-hobby thing may be well and good in its own right, but in the absence of knowledge of what you're trying to apply it to, it's somewhere between irrelevant and actively dangerous.

In reply to martinturnchapel:


Much more inlined to jam when pulling down than a overhand knot though,


Chris

In reply to AlanLittle:

That's actually a brilliant point (though probably repeated in this thread). To accompany that, most of my climbing partners cannot or are not able to check whether my Grigri is set up properly as only few of them own them and know how to use them. I once managed to set-up it upside-down and my climbing partner was completely okay with that. On the other hand, failing to set-up an ATC would be difficult and it's easier to inspect discretely.

The last word, discretely, is the most important thing - very few experienced climbers dare to check each other by holding the knot/belay device or check whether the screwgate is shut, but they can actually tell from a distance that everything is okay.

In reply to martinturnchapel:


Should *never* be called reef knot with stoppers when it's more properly double fisherman's with reef knot separator. And that's not a pedantic distinction but a clear declaration of usage when folk have died using reef knots as bends and it's your 'stoppers' that are really joining the ropes here! Though, like the others, I can't really see why you'd need it when you've got the long-tailed overhand...

In reply to PPP:

It's a major reason and legitimate why the bowline is often frowned upon as a tying in knot these days. I personally still use it for single ropes - rethreaded DAV-style - and I think that's defensible because I live in Germany these days where most active sport climbers are familiar with it. But when I hear about all the Yosemite / Edwards / clove hitch / whatever things that go under the name of "double bowline" in Britain or the US, then I can see that there's a strong case against them because nobody can reasonably be expected to recognise and visually check all of them.

In reply to PPP:


I had a guide who advocated it as the way to tie ropes for abseiling, had all the advantages of the EDK but was easier to untie. At the time, I knew of the pull test results, the failures from knots rolling off the ends. I suspected fatalities but couldn't actually name a specific accident.

They were one of the most experienced and qualified mountaineering guides I've had. I was sort of surprised. I pulled out a textbook we had at the time, skipped to the "don't use this knot" bit. He mentioned they'd been doing it for years and never had an accident.

Which is about what you'd guess would likely happen, for years he'd been dressing and tightening these figure of eights and for years they hadn't been rolling off the end.


So, in response to the poster up above that suggests looking at peoples profiles - maybe it'll help, maybe it won't.

The original question was what do you use and why, which is a bit different from someone asking what they should use. SenzuBean had some interesting things to refer to (from AK page, to Toms page, there's a reference to an overhand knot failure resulting in an abseiling accident) - valid things to come up in a discussion about abseiling knots. He went as far as proposing his own idea, not for use but instead for testing. He didn't really present what he uses, so wasn't precisely on topic. But, none the less, I applaud his efforts.


As to what I use....I don't abseil a huge amount. I'm still working out what I prefer. Typically it's an EDK. At times I've added an overhand to resist rolling. Other times I've used a regular double fishermans, owing to some partners not liking the EDK. I'd like to start using the DT-FK some of the time (the flat double overhand that SenzuBean linked to), it looks to be an interesting improvement on the regular double fishermans for joining abseiling ropes - I'd like to experiment with it in thin cord and a bit of load to see what happens for my own confidence. I suspect it won't cinch as tight as the regular double fishermans, but will go over edges nicely like the EDK.

In reply to needvert:

"working out what you prefer" is not something id recommend with an abseil knot......

In reply to eivrol:

overhand knot or even a double overhand knot (another overhand on top of the first overhand) if you're paranoid. perfectly safe with ropes of equal diameter (a few points of a mill doesn't matter here.).

If you're really paranoid or have ropes of different diameters a reef-fishermans knot (I forget what it's real name is) is pretty safe and easy to untie.

In reply to SenzuBean:


One example does not mean "a lot of disasters", like you stated above...

I can tell another example of fig. 8 knot rolling open, so clearly fig 8 and EDK is equally deadly .

In reply to OP:

This has been an interesting thread to read; thanks to the contributors. I have always used a double fisherman's, but am pretty happy to switch to a double overhand now (leaving the right amount of tail).

highclimber raised a point which stuck out for me; ropes of different diameters. Am I right in assuming that most people are advising these knots for ropes of the same diameter? Same-diameter half ropes are certainly what I would use for the majority of trad routes in the UK (and I have zero alpine experience so can't comment there). However, I've climbed a little bit across the pond too, and the norm (in BC at least) seemed to be climbing on a single 10mmish rope (due to often straight pitches), with the second carrying a thinner (lighter) half rope for the abseils.

What's the advised convention for this scenario? Is the double overhand still good for (I guess potentially) up to 3 mm difference? Or is the 'double fisherman's with reef knot separator' more appropriate (but perhaps more snaggable)?

In reply to Ben Snook:

I don't know what the advice is, but I quite happily mix and match half ropes and, as an experiement at the local wall one day I happily hung (over a crash pad !) from a 10.5mm rope tied to a 6mm cord with a single overhand. Not that I'm advocating this as safe, just as a reassurance that with well dressed overhand knot, rope size difference is not *that* critical

In reply to eivrol:

thanks for all the replies and the interesting discussion. I hope you got as much out of this thread as I did. eivrol

In reply to eivrol:
I think the first two posts with the links to Andy K's website and the Needlesports website. I have always used a Overhand knot with suitably long tails (about 1 meter ish). I always explain what I'm doing and why with climbing partners when I use this knot and I'm always happy to use a double overhand if they're not happy with the single. But most people haven't done any research into the knots and really thought about why they use it. I have, so my sensible balanced view tends to win most people over. I've been using it for 5 year and lots of abseils and I'm not dead yet!

Just make really sure that you dress (pull it really tight) the knot well. I'd use a different knot if I was joining two very different rope sizes together, but normally I'm using either 8mm or 8.5mm ropes.

In reply to eivrol:

I use an EDK - single over hand knot. If someone I'm with balks at that, and I'm not worried about pulling, I'll do a double overhand. Or, I'll let them ab on the double, then untie to a single overhand for my ab & pull.

For greatly differing rope thicknesses, I would be a bit worried about the thinner rope pulling through -- so I would do a single overhand, with the thin rope's tail knotted (overhand) once around the thicker ropes tale as a backup. This does not add very much to the knot bulk for pulling since the extra knot is only in the thinner rope.

In reply to Ben Snook:

Lots of useful stuff here: http://people.bath.ac.uk/dac33/high/10GettingBackDown.htm
In it I refer to tests down with a 2mm difference and the overhand was fine.

Hi, not nice.
When you saw the knot roll did it roll more than once? The test data, even with wet ropes, suggests that only one roll at most is possible, hence if the tails are more than 60cm one should be safe.

And do you have the details about the Spanish climbers you mention?

Thanks

In reply to eivrol:

overhand or double overhand depending on state of mind at the time.

In reply to David Coley:

You are right, loads of stuff there, thanks! I'm looking forward to reading it (but probably shouldn't whilst at work...)

In reply to dagibbs:

Elegant solution, thanks for the suggestion.

In reply to dagibbs:

Once you get into really big differences in diameter then the knot is only one issue. The other is the speed the ropes pass through the belay plate. This means you will reach the end of one rope before the other. This is why you might switch to a single line rap and use the thin rope as a pull line.

In reply to David Coley:


Yes, also a good choice once you reach enough difference.

In reply to David Coley:


Yes, but you forgot to add that the knot and rope will then be moving relative to the abseil point.

With the thin rope through the ab sling, the knot will move away from the ab sling possibly damaging it with the friction under tension, not good.

In reply to David Coley:

Aye, but whoever goes out climbing with, say, Oh I don't know, a 50m 9mil and a 50m 4mil?

In reply to Lusk:


Have you heard of tag lines?

In reply to Rick Graham:

Yes I have, but I've never know/heard of anyone go out with one.

In reply to galpinos:

Perhaps it's because his ab is not backed up to the second bolt.... )

In reply to Lusk:


I have done so while climbing in the Alps a few years back. Was actually a 60m rope & 60m tag line -- just in case.

In reply to Rick Graham:


Rick, that is exactly what I meant. I just didn't explain it as well as you!

In reply to Lusk:


If 10mm and 5.5mm counts, then me.

In reply to Lusk:


I am Spartacus ( tag line person )

A specialist technique in the UK, but more common in the Alps and certainly the US

In reply to David Coley:


An in case anyone asks why, an example:
Climbing on a single rope on a long rock route with an easy descent of a couple of long simple clean raps off the back of the hill.
Why use a single? Speed - one can belay safely at high speed with a grigri / allows the use of microtrax's so you can move together / allows easy flying swaps (search for Redirect Belay: the Flying Swap, at http://people.bath.ac.uk/dac33/high/6TheBelay.htm ) / less rope at the belay.

In reply to eivrol:

what ever knot you choose, make sure to double check everything. make sure the rope is though the belay device correctly and that you have knots in the end of the live ropes. also a prussic or back up should always be used. weighting the system before stepping over the edge is always a good idea if possible.

In reply to David Coley:




But we both forgot to stress that the ab point sling could be cut with fatal results!

In reply to Rick Graham:


Has that ever happened?

In reply to David Coley:


Not to my knowledge.

However, using a tagline once and getting significant differential slip and stretch in the system soon raised alarm bells in my self preservation auto pilot. It was probably the 600 metre fall potential that made me think quick!

Solved it by putting both ropes through the same hole on the DMM Bettabrake I was using and checking the ropes and knot as I descended.

In reply to Rick Graham:


One solution to the problem of the ropes moving relative the the ab point if one rope is fat and the other thin is simply for both climbers to put their belay plates on the rope at the same time. The ropes are then stopped from sliding by the second's plate as the leader raps. The leader then just holds both ropes as the second raps.

Job done.

In reply to David Coley:



Is it possible to abseil if someone is holding the rope?

Ensuring the knot is on the skinny rope side of the anchor should stop the rope moving,


Chris

In reply to Chris Craggs:
Holding it, but not pulling tight, yes. if the person holding the rope can feel one rope get tight he can inform the one on the rope to let more rope go thru one side.


Edit: assuming the rope isn't threaded through nylon/dyneema tat!

In reply to Chris Craggs:


The force required is very small: you are just trying to stop the thin rope heading upwards.

If the chain rings are small this would mean re-tying at each anchor assuming you are pulling the rope down in the normal way through the lower chains.

In reply to David Coley:


Well if it is a ring, the moving rope isn't really an issue is it? I thought this was all about not melting a tape sling, retying wouldn't be an issue, you could just poke the knot through the tape.

Chris

In reply to David Coley:



Not quite as simple as that.

1 . I was soloing when I first had the problem.

2. if the thinner rope is through the ab point, it is the one stretching more so no point holding it at the bottom.

3. if practical, I like the thinner rope thro the ab sling, so as to pull the thick one. This means easier to pull, and if the rope jams/snags, I am not left at the lower stance with a ball of string and not a climbing rope!

I tend to use a screwgate krab to join the two ropes, less knot conundrum, quicker to change/ attach to next ab anchor and not usually a problem with snagging (though a water knot is usually best)

Sorry. This has all been covered in previously on UKC.

In reply to Rick Graham:


I thought the issue was slip, not stretch.

In reply to David Coley:

Slip and stretch.

As you abseil down a truly 100% static rope, all the height lost is equal to the movement of the abseil device.

On equal dynamic ropes part of the height lost is due to the stretching of the rope as the abseil device moves down it and there is more rope available to stretch.

On unequal ropes, this is not symmetrical so if the thinner rope is through the ab anchor, the extra stretch will make it ( and the knot) move relative to the ab point.

There is also the issue of the unequal ropes offering different friction in the ab device. This also tends to make the thinner rope slide thro the anchor sling.

In reply to David Coley:


Just thought of the solution.

A thin light rope that has less stretch. Dynema cord. Not cheap though.

I bet the only way to get elongation figures is to try two long lengths of Dynema and climbing rope out on the crag or climbing wall.

This is what I have experienced, not the stretch. I know this as it can happened even after only a few metres of abseil and be considerable.

In reply to Rick Graham:



I have used a 9.8mm dynamic with a 5.5mm dynema a reasonable number of times, but as a pull cord, so not the same.

I own a very small old fig-8. I have always thought this might solve the issues as it would be hard for the ropes to move relative to each other. But I have not tried it.

In reply to David Coley:


Between Slip and Stretch, you are probably correct that slip is greater.

But, as the abseiler you can assess the slip differential of the two ropes thro your ab device in front of your face.

The stretch is only visible with the knot movement relative to the ab sling at the anchor.

I found the best solution to be putting both ropes though the same hole on the smallest belay plate possible. This nips the ropes together and the friction on the two sheaths minimises differential slippage.

In reply to eivrol:

how come no one suggested this?? :-D

youtube.com/watch?v=TUHgGK-tImY&

In reply to eivrol:

A good one!

In reply to eivrol:

Some thorough testing from the field of canyoneering found overhand with long tails to be best for joining two ropes together: http://caves.org/section/vertical/nh/52/PreferredKnots.pdf