This is the twelfth in a 12-part series from Climbing Magazine, Wild Country and Red Chili, demonstrating and explaining the basic skills needed to be safe on the crags. In this episode, Julie Ellison, Climbing Magazine's Gear Editor, talks us through two useful knots for use when abseiling. Firstly, she shows us the overhand knot, used to attach two ropes together to allow a full-length, retreivable abseil. She then shows us a knot to be used on the other ends of the ropes to prevent the climber from accidentally abseiling off the ends of the ropes...
In reply to UKC Articles: I've used the simple overhand knot for abseiling without problem. Now for some reason in France there's a new official reccomndation that the fig8 be used instead (tied as for the overhand on the double). Maybe someone can enlighten me as to why it might be safer?
In reply to UKC Articles: Nothing official. Various discusiions come up (in french ) if you search on "neoud de 8) + rappel. The comment is that it's 'more resistant'; greater detail would useful. Incidentally I've tried the fig8 in this context and not had any problem.
> (In reply to UKC Articles) Nothing official. Various discusiions come up (in french ) if you search on "neoud de 8) + rappel. The comment is that it's 'more resistant'; greater detail would useful. Incidentally I've tried the fig8 in this context and not had any problem.
"To tie the figure of eight correctly requires that both ropes travel a particular path through the knot. This is very difficult to ensure in a stressful situation. In addition to this, the knot has an alarming tendency to roll along the rope when stressed at right angles to its main axis.
Most stuff I've read recently points to the _double_ overhand being the safest knot to use to join abseil ropes (taking into account the risk of the knot rolling, getting jammed, and being able to untie it once it's been loaded).
Double fisherman's is safest in terms of knot strength/stability (but prone to jamming), double overhand is safe (assuming well tied with good tails), single overhand will do if you're worried there's a high risk of jamming (but make sure it's well tied with long tails)
> Nothing official. Various discusiions come up (in french ) if you search on "neoud de 8) + rappel. The comment is that it's 'more resistant'; greater detail would useful. Incidentally I've tried the fig8 in this context and not had any problem.
The first problem you do get will likely be your last. Don't do it again!
re the double fisherman's jamming I was taught to use a reef knot with fisherman's as a stopper each side. The fisherman's aren't loaded as much as the reef and so are easier to undo.
Might be more prone to catch when pulling through though, and only any good on rope of the same diameter.
In reply to cuppatea: Yup - I seem to remember using the same in the dim and distant past on cracky (ie jamming) alpine routes as an alternative to a full double fishermans. Must have dropped off my radar at some point though as I've only used the double overhand in recent years. It's always good to have alternatives though, as long as you're happy/confident in using them.
Not got any data on me, but I did some tests on this a few years back. The fig-8 will roll down the rope at a lower load than an overhand. It also does so in a rather untidy fashion.
You'd be very unlikely to reach the forces required to roll an overhand during normal abseiling, though I have spoken to rescuers who have seen it happen with two-person loads. Hence the usual advice to leave long tails.
It's got a couple candidate abseil knots I hadn't come across before - a double-T fisherman's (a double fisherman's tied with the loaded ends on the same side) and what they term a triple-T overhand knot (looks like a single fisherman's with a locking knot). In their tests both these out performed a single overhand knot. Shame no test against a double overhand.
Maybe I'm not understanding how the knots work, but the double-T fishermans looks like a potentially terrible idea - if the blue part of the knot jams on something isn't the red part then free to slip down the blue rope?
In reply to LeeWood:
Although disagreeing with those FFME pages seams like disagreeing with the word of God, they are I believe wrong and dangerous. For one, although it discusses tail length in the text, the images show a tail length that will kill you.
In reply to David Coley:
I've got to agree with you. I've been keeping an eye out for this sort of data for a while and it is so easy to find test data that scares the crap out of me in relation to using a figure of 8 in this way. Two seconds with Google turned up this gem that I hadn't come across before: http://www.caves.org/section/vertical/nh/52/PreferredKnots.pdf
In relation to the figure of 8...
"All 9mm rope specimens tested had at least one roll back, four rolled back twice and one specimen rolled back three times. The lowest first roll back occurred at 2.1kN ( the weight of two abseilers) Graph B-6 is typical of the slope on the graph of elongation verses load, which was dramatic, as the knot displayed either partial or complete roll-backs.
Significant “Tension” slippage was already occurring at the abseil-working load, with an average “Tension” slippage of 165mm. “Tail” slippage was only an average of 10mm.
Average “Tension” slippage at failure for the 3 sets of tests conducted was 410mm. On one specimen the “Tail” had slid in 120mm to the point where the tail was flush with the knot before it broke. Another specimen had a “Tension” slippage of 633mm at failure. No significant slippage difference was noted between wet and dry samples.
Another example of how dangerous this knot can be is to tie the knot with inappropriate tail lengths and have the knot poorly packed. In this configuration, it is possible for two people pulling in a tug of war fashion (which equates to approximately a 50kg load) to pull the knot completely apart. For the reason of roll back and knot failure this knot was deleted from further testing."
I shared an abseil with an experienced Swiss couple last year on their double ropes (oversight on our part - we had a 60m abseil and only a single rope). They happily used a fig 8 for their knot. Needless to say we watched the knot very carefully before comitting to the abseil ourselves - I think once really well seated and jammed up tight it seems to be stable but not one I'd choose.
My apologies I had no idea such they are really dumb advice was out there so thanks for pointing it out. Figure 8s roll when cross loaded way more than overhands do. I'm amazed they havent updated their advice on this.
This is the advice on the BMC pages:
This issue’s expert is Steve Long. Steve is the Chief Officer of MLTUK, producer of the Self Rescue DVD, author of Hillwalking by MLTUK and The Climbing Handbook, and no stranger to abseiling.
Q. What’s the best knot to join two abseil ropes?
A. The one that doesn’t creep undone! There are plenty of choices but for security it’s hard to beat a reef knot with double stoppers on each end. However, this knot is likely to jam on any projecting rock ledges or cracks when pulled. An alternative is the overhand knot, which is less inclined to jam – just make sure you leave tails of about 50cm to account for any slippage."
Does the confusion with the figure eight come from the method? You could tie the figure 8 on the bight, which is likely to roll. Or you could tie a retreaded fig.8 which is bomber (same knot most people tie in wih!) the biggest problem is the time it takes to tie, bit faffy so I always go with double overhand
The blog author critiques the book for proposing a) double fisherman's & NOT fig8, because he was instructed directly through the Brevet d'Etat (state diploma) the opposite. The instructer (formateur) justified his reasons.
He finishes the critique by saying the book has limited value, there is no substitute for direct instruction.
In reply to LeeWood: saying what a knot can be used for is not the same as a recommendation for its use over other methods which is what you said was the case in your OP. Provide us with a link to where you saw this recommendation and we'll have us a dis ussion. Otherwise this thread is pointless
In reply to UKC Articles:
Been using the double overhand / euro death knot since I was first shown it 20+ years ago. The obvious advantage of not having the knot jam on every abseil, coupled with the associated dangerous retrieval antics, and the fact that I have never seen any movement on the knot itself are persuasive for me (though, to be fair, I don't do simul-raps or heavily weighted ones with haul bags etc.)
I am paranoid and have taken to adding a second double overhand on the tail, properly dressed and snugged up against the primary knot. My rationale is that this should catch any rolling of the primary knot, and it doesn't seem to add significantly to the likelihood that the knot will jam on the pull.
Again, because I am paranoid, I leave very long tails (well in excess of the posted recommendations) and there is a risk associated with this. A couple of years back my wife grabbed me by the harness as I was about to take the big skyride - I had clipped my abseil device into the long tails rather than the "live" rope. This scared the shit out of me, and I have thought about it since. Partly of course I was a f*ckwit. However I think an additional risk is that, if you extend to your partner the courtesy of pulling up the abseil rope in order to make attaching the abseil device and clipping it easier (without the dead weight of the 60 metres hanging below) then you also deprive them of that sense of being on the right - that is, the heavy - end of the knot.
Knot an excuse of course, but possibly one to think about.
The dangerous inferiority of the flat figure-8 (the figure-8 version of the Euro Death Knot) has been known in the US for fourteen years now, first from Moyers' tests in 1999 linked above and then reinforced by the tragedy on Space Shot also referred to earlier. It is truly amazing that this knot is being listed on web sites devoted to climbing as a way of joining ropes; the idea that this doesn't constitute a recommendation is absurd, and the presence of the knot without a warning about its propensity to roll is negligent.
In reply to highclimber: Despite my 30+ yrs participation in this sport, I had never been aware of UK advice on the fig8, so I am grateful for this thread content. The persuasive recommendation which I was given (May last year) led to my largely converting to use of fig8 and I had no physical problem with it (long tails, properly dressed etc).
What I cannot locate in french media is a stated result of fig8 researched testing; I shall forthwith return to the use of the simple overhand.
The layout of that article seemed to have gone crackers! I have revamped now so it displays properly, and removed a link that no longer worked. It was written after a local climber fell some 70m and suffered terrible injuries as a result of the figure eight abseil knot failing. The conclusion is that the term "Euro Death Knot" should be applied to the figure eight, not the overhand! And that the overhand is made safer by putting a second overhand in, butted up tightly against the first. This is safer for two reasons. 1. There is less likelyhood of the knot rolling undone. 2. You have to think about making the knot more so there is less likelyhood of an error when you are really tired.
I'm not a fan of the double overhand. It creates a large mass with which, I think, interferes somewhat with the way the overhand rides over obstructions, because the larger knot is more prone to flopping over sideways rather than standing up, and then you are dragging a fairly bulky object down the face. The single overhand with forearm-length tails is fine for ordinary rappelling.
If the ropes are soaking wet or the rappel involves greater than single bodyweight loads, I tie what I guess you'd call an overhand and a half---I tie the second overhand with just one of the strands, which makes for a more compact package. However, there is a trick about selecting which of the two strands to use for the backup knot; one of them will be more functional than the other, and selecting the correct one depends on understanding of the rolling mechanism of the knot.
I've tried to explain this with the following three pictures, whose original aim was to address the use of the EDK in different diameter ropes. The third picture illustrates the extra overhand, and the same principles apply when the ropes are the same diameter: tug the strands apart as they would be for rappelling and see which of the two strands in the knot these opposing loads are most immediately applied to. This strand is what I called the "roll strand," and it is the one that should be used to form the extra overhand knot.
No tests other than actually using the knot for rappelling---maybe Jim could do some in his abundant spare time? I've used the method a few times with a 7mm and a 9mm, and some years ago with a 9mm and an 11mm.
Because the difference in diameters actually inhibits rolling if you set up the knot correctly, I think the knot tied in unequal diameter strands as pictured (with the extra locking overhand) is likely to be stronger (in the sense of not capsizing) than the same knot tied in equal-diameter strands. But this is hypothetical, so caveat rappellor.
In any case, I'm only suggesting here the possibility of using the method, as a more compact alternative to the double overhand, with two ropes of the same diameter.
In reply to UKC Articles: Changing the subject slightly, is there any particular reason for using (what I think she called) the triple-barrel knot for the ends of the rope to prevent abing off the ends? Rather than (as I tend to do) an overhand on one, and a fig 8 on the other - so I know which one to pull?
In reply to Jamie Brown: The main advantage to barrel knotting each strand is that if the rope twists as you decend, they will beable to twist free. if you tie the ends together as one untwists it twists the other and vice versa. not really a problem for shorter abseils but highly annoying if abing towards the ends. Tying both ends together does give you the oppotunity to pull the rope back down should you forget to untie the ropes. individually tying them could be a big problem if you forget!
I prefer to ty both ends together rahter than individually for the reasons above and because its a hellova lot quicker too!
> (In reply to jon_bee)
> Maybe I'm not understanding how the knots work, but the double-T fishermans looks like a potentially terrible idea - if the blue part of the knot jams on something isn't the red part then free to slip down the blue rope?
> (In reply to UKC Articles)
> Does the confusion with the figure eight come from the method?You could tie the figure 8 on the bight, which is likely to roll. Or you could tie a retreaded fig.8 which is bomber (same knot most people tie in wih!)
No both methods results in the same the same knot which is unsuitable for abbing.
(maybe you are confusing with the fo8/flemish bend)
In reply to LeeWood: Interesting- we shared ropes in the summer with a very experienced French couple abseiling. They tied the ropes with an 8 knot & were surprised when I insisted on using an overhand- this explains it!
In reply to Jasonic: Yes, I see conflict ahead if/when I next climb with the locals. However, thinking about this logically, failure potential cannot be quite as bad as some folk make out. There are evidently thousands of continental climbergs using the fig8 and if there were (more) incidences of failure someone would have clocked it and raised an alarm. I think we're discussing degrees of safety.
In reply to LeeWood: Clearly when tied correctly it does work as many people seem to use it but there has also been at least 3 (that I've heard of) deaths or serious accidents from it. So it is about degrees of safety but I think you should always aim for best practice and always adopt better methods if you come across them. That way when you make small mistakes, as we all do, the margin of safety is as high as it can possibly be.
In this case I think a plausible scenario is that someone gets distracted whilst tying the knot and forgets to tension it. Hard to spot as a tensioned and un-tensioned knot look very similar and the extra resistance of the overhand to flipping could make the difference. In fact after reading it on this thread I'm going to start adding the half fisherman's tie off because it makes the overhand even less likely to flip and still keeps all it's benefits.
So although the fig8 can work I don't see any reason why people would continue to use it after learning about the overhand and it's increased safety.
I've played with a 6mm cord joined to a 10mm climbing rope with a single overhand knot at the wall once. I couldn't 'bounce' it into failure. Thats why I'm more than happy joining slightly different diameter ropes with a single overhand.
First point : it will be a good step towards clarity of understanding if we lose the misnomer "flat" in favor of the apt adjective "offset" in naming this and like knots (so, "offset water knot", "offset fig.8", "offset grapevine", e.g.) ! They are **offset** from the axis of tension; they are not flat. (credit Clyde Soles for this)
In reply to David Coley:
It should be emphasized that the >>important testing<< for an abseil-ropes-joining knot can be done by individuals using their own particular ropes and a simple, crude, 2-to-1 MA pulley system to exaggerate force.
Consider : typically, an ARJ knot will see one HALF of the force generated on abseil; if one loads the knot (in this "individual testing") on single strand --in contrast to typical loading, you see-- AND uses a 2:1 pulley (with, say, just a 'biner (which will thus be more like 1.5:1)), and with some "bounces", these test forces will go well beyond (in multiples) of what typical use will generate. This should be all the testing that is needed. I.p., break tests done by who-knows with whatever-ropes and device driven slow-pull are hardly so relevant!!
As I have pointed out long ago (in detail on RC.com and that referred to from time to time in other places), there is more to this ARJ "EDK" knot than most folks realize (sadly, even AFTER having pointed it out and tried to bring to others' attention!). (RGold, however, got part of the point and thus produced clarion images --thanks!
The advice is seriously wrong in two points, at least:
1) The tightening of the knot should be done with specific manner to its expected loading, not simplistically on all ends in some lame thinking that this must cover everything --it doesn't, but treat everything as being equally important when in fact there are two ends that are mere tails and two that get the force (and there is a desired tightening that comes from a particular loading).
In short, the given advice is fine as a preamble to final setting --it gets out much material, good. The final setting should be of the particular tail that leads to the line making the real/initial *choke* of the loaded ends' entry into the knot (and this should be the thinner or more flexible of two lines if they're dissimilar, as RGold shows and I elsewhere describe & show (@RC.com)).
2) It is definitely NOT some mused "rolling" that helps the knot be pulled down!! --goodness, where did such mistaken rationalizing come from? Rather, it is the **offset** (please, not "flat") aspect, and compactness, that facilitates the knot's movement over rough surfaces & edges.
> failure potential cannot be quite as bad as some folk make out.
> There are evidently thousands of continental climbers using the fig8
> and if there were (more) incidences of failure someone would
> have clocked it and raised an alarm.
> I think we're discussing degrees of safety.
This is a good point. Some have failed and some have raised the alarm --incl. me, e.g.--, but I must admit that I've not pulled (bounced upon ...) an offset fig.8 end-2-end knot to failure. And I'm aware of the testing that Tom Moyers did with some ropes (same & mis-matched diameters, in wet & dry conditions), and his results suggest that the knot is generally secure *enough*. And the Zion tragedy involved ropes that I heard from someone who claimed to have handled them to be "like cables" --i.e., firm & stiff, not conducive to happy snug knotting.
But there should be some concern, given the few documented failures. (I'm surprised at the easy time the Bushwalkers (Australia) PDF report cited above gives for pulling one to capsize!?) And one must challenge why the fig.8 should be used, when the offset overhand works so well, and for so long, by so many (and without even the few reports of failure --there was one, dubious case in the states, IIRC, w/a trio incl. injured "Karen"; quite unclear details).
.:. The overhand is much more easily, naturally formed, checked, and set; and the simple extension to this of tying off the right tail (or both, in a 2nd like knot, if discerning which end to tie off is too challenging --YMMV) is a very simple thing to learn / remember / do.
> How can you out perform the simplest possible knot to tie (with or without gloves) which never comes undone and which has the least chance of getting caught ?
!! Spot on !!
But w/some disdain at the offset water knot's usual baggage of "leave tails long", DO something with those tails (or the one, as RGold & I show) and be done with even the hint of doubt --tie the bloody tail off instead of leaving it long!
Yeah, folks like numbers, as though the knot holding a 2 cars is better than that holding 1.5 for an abseiling task. But numbers are so easy.
As I try to emphasize, for THIS use, each person should be able to do relevant testing (body weight on single strands and so on); don't look to some break tester's numbers.
> It's got a couple candidate abseil knots I hadn't come across before - a double-T fisherman's (a double fisherman's tied with the loaded ends on the same side) and what they term a triple-T overhand knot (looks like a single fisherman's with a locking knot). In their tests both these out performed a single overhand knot. Shame no test against a double overhand.
Josh's names for knots are not to be replicated, please. Clyde's "offset" works fine here, with the only debatable issue of how one might care to preceive Josh's novelty (something earlier proposed by Austrian Heinz Prohaska & shared by him with Bachmann, to drop some names . That knot could be seen as an offset (single) fisherman's knot backed up with an overhand, or as the same *guarded* by an overhand --i.e., the first-resisting knot seen as protecting the fisherman's from offset loading. (FYI, one can form the three overhands in any order!) He might have also tried putting the two overhands of the one line adjacent, with the larger rope's overhand on the tails side; that might've resisted the pulling through (which we'll note came only at a load not to be seen in abseiling).
The offset grapevine (aka "dbl.fish.") shows some inefficiency : the added turns in the double overhand structure (or "strangle knot" component) work well to resist being pried apart in the half of this knot that is choking the loaded ends; but that extra turning is superfluous in the other half, which is loaded qua stopper knot, and so might as well be just an overhand. An Australian fellow has favored tying the strangle knot (the "half of a dbl. fish.") with the two ropes and using that as the ARJ knot; I think he'd tested it.
But back to the top : there IS a simple solution, with a simple assurance via a tie-off.
Wow, this is really bad! I hope that the BMC via the discussion here (including the cited references --esp. those of Tom Moyer, my own, and the testing of offset water knot w/tie-off) can urge the FFME to redress this bad advice. That re the tails on the offset fig.8 is, as you note below, bassackwards on two counts : risk of flyping AND amount of material consumed per flype.
> Note the advice on tail lengths - for the overhand 2x longer, implying that it is the one [more] likely to roll.
RIght, and even more than you state, per Moyer's testing :
the offset fig.8 knot is
1) more vulnerable to flyping;
2) more likely to CONTINUE flyping (vs. tightening);
3) more rope-(tails)-consuming per flype!!!
"3 strikes and you're out!"
I could probably add some things about the offset fig.8 having more variations of formation /orientation, but its coffin should be adequately nailed as it is. --and noting, yes, the observation made above about degree (ameliorating our concerns, but ...), STILL, there is the simple and more sound solution, so let's be rid of the risk.
(That fellow who claimed familiarity with the ropes of the Zion tragedy, e.g., continued to present the offset fig.8 for use --but has since dropped that--, and some other organizations had recomended it as well. So, it can't be failing left & right; but it can be a risk not worth being exposed to. The irony is that it's probably recommended with the wrong-headed thinking that if the offset water knot is okay than a fig.8 subbed for the overhands must be even better --when just the opposite it true!)
> First point : it will be a good step towards clarity of understanding if we lose the misnomer "flat" in favor of the apt adjective "offset" in naming this and like knots (so, "offset water knot", "offset fig.8", "offset grapevine", e.g.) ! They are **offset** from the axis of tension; they are not flat. (credit Clyde Soles for this)
I'm struggling to follow your reasoning. How can randomly renaming knots improve clarity?
"What is 'flype'?" Touche' --well, I thought it appeared in more than full dictionaries (in collegiates, i.e.), but ... . It's a term meaning to peel back such as removing a sock, inverting it. (Use or lose, and this old Scot appears to be getting lost.)
in reply to timjones:
The term "offset" comes from normal uses and fits; "flat" comes from who-knows-where and doesn't. Myself, I've gone from adding "overhand" (per Soles) to "ring bend" (is that clearer --maybe not), now to "water knot" --as I think this latter denotes just one structure, albeit often seen by rockclimbers as something tied in tape (where, though, it is in fact sometimes loaded in the offset manner (and one fellow tested it --not great result, btw)). "Offset" speaks to the geometry and purpose of such tying.
For ample confusion in knot names, just look around : here, i.p. there is "double overhand" which is used quite differently than elsewhere (referring thus to an overhand tied with two ropes; or to one tied with a bight, vs. the "half-a-grapevine/dbl.fish", strangle knot version, and beyond that to topologically equal knots such as the fisherman's BEND (aka anchor bend/hitch)! What to do? It grows further confused on some of these when venturing into the arborist world. And then the Brits go on with "larksfoot" vice "larkshead" after March's published mistake, roughing the connection to the French name.
In reply to LeeWood:
"going into this more than most of us ever will" ::
Alas, though, in terms of typed lines / keystrokes, the volume can be as great from others through repetition of the same ol' misthinking(s) --the repeated bowline-vs-F8, EDK-Kills, ... threads
My hope is to show some rationale for things (e.g., to deflate the mistaken thinking that leads folks to tie offset fig.8 vs. offset overhand; or that the grapevine should need full tying when offset-loaded (my contention : the away half can be an overhand)).
In reply to jimtitt:
Well, Jim, maybe you should cut back on the coffee and read more carefully.
And there are just the images, after all --to complement or suffice on their own.
(rather sad to get such a comment from you, really)-:
One further point to be added:
In some like discussions of joining abseil ropes raised on RC.com years back, a good many long-experienced climbers reported using the grapevine without the snagging hassle that the offset water knot is intended to prevent --so, 20, 30 years of regular usage w/o hassle (or in some cases a problem that the other knot wouldn't have avoided).
I decided to look further at the FFME site to see what else might be surprising.
Something else IS : their "noeud du chaise" --the bowline, in English-- is the "Eskimo bowline", which is where the rabbit goes the other way through the hole and around the *root* rather than the "tree"'s trunk, so to speak!! I'm surprised if this is really intended.
--to wit >> www.ffme.fr/fiches-ffme-techniques/page/confection-du-noeud-de-chaise.html
While this other eyeknot isn't terrible, it is an uncommon thing in my awareness, and not to be preferred (IMO).
(Btw, I didn't have luck in chopping the above-cited URL or otherwise clicking; I used Google on the URL stem to get like links.)