UKC

Was down at the climbing wall a few days ago when a debate broke out about the use of a stopper knot;
I regularly climb with just a figure of eight and only use a stopper knot if I need to tidy away excess rope.
One of the people i climbed with argued that it was integral to safety on the off chance of rope slip.

Are there any cases of fig eight knots failing when tied properly with a couple of inches of tail, I’ve been googling to try and find dmm pull or drop tests but haven’t come across any that covers this.

In reply to James90:

I like it as a double check thing, especially for teaching people. If you've got a few feet of tail left you've probably done something wrong. As things go with a few inches of tail I doubt it will fail, if you're in a situation where a fig 8 destroys itself you're probably in the s*** anyways.

How about a situation where you clip into your rope loop and the knot 'rolls' open?

In reply to James90: my understanding is that it's not to do with rope slip (it's a self tightening knot), but more to ensure you have a long enough tail. Apparently there is a vague possibility that the knot can invert it's self with not enough tail, so if you have enough to tie the stopper then you have enough tail, and then you are as well tying the stopper to keep the rope out the way!!

In reply to James90:

A fig eight used to tie in does not need a stopper, simply a minimum of 10cm tail.

A simple bowline used to tie in does - absolutely - need a stopper.

These two facts have been mixed up over the years leading to people regularly stating that a fig eight must have a stopper when used as a tie-in. They're wrong. It's a good way to get spare slack out of the way, but better is to tie it in the right place and not waste rope. More here: http://www.ukclimbing.com/articles/page.php?id=4755

The inversion thing won't happen to a fig eight when it's used to tie in - it happens when there's a two-way load on the central loop. So if you were to take the central loop having tied in and connect it to two very large sideways opposing forces, the knot might start to invert. I have no idea if a stopper would do any good in this scenario!

In reply to Jamie Wakeham:

In climbing there are a few scenarios I can think of where a cross-loaded tie in loop can occur e.g. belay directly from the tie in loop into a single anchor i.e. a sling, attach belay plate to rope loop and then have your leader take a ff 2 onto it. However that is a momentary peak load so it is only likley to roll once... if at all.

In rescue rigging (which enjoy high static loads stopper knots aren't used on 8's...4 inch tails are).

In reply to James90:

My understanding of the reasoning is:

Protects the climber if the knot is tied incorrectly.

If there is enough tail to tie a stopper knot, the tail is long enough, if you haven't got enough tail to tie a stopper, your tail is too short.

Protects against the knot rolling if side loading it in a belay.

My favourite one is the middle one - tie a stopper to prove the tail is long enough to not need a stopper!

Dom.

In reply to simondgee:

>...belay directly from the tie in loop into a single anchor i.e. a sling, attach belay plate to rope loop and then have your leader take a ff 2 onto it...

Sure, but that's not a recommended way to connect to a single anchor point. Better to use a clove hitch on your end of the rope - it both puts a dynamic element into the system and removes the cross-loading.

What I don't know is if doing this, and then bringing a second anchor point back to the central loop with a karabiner into it, constitutes cross-loading. I suppose if you've got the tensions wrong and the krabbed one loads before the actual end of the rope, it might cross-load? Again I would suspect the dynamic element of using the rope means that the forces are too small to be concerning.

In reply to Jamie Wakeham: Nice one

In reply to Jamie Wakeham:
yeah...however I think we can safely assume that there are lots of people not doing it a 'recommended way' ....and might do this...I guess having bullet proof over engineered systems e.g. stopper knots on 8's when 'learning' is an insurance policy...especially for walls and instruction and helps protect against other minor compounding errors of inexperience.
FWIW...In my personal climbing I shout Safe when I am happy to be wandering around unbelayed, I tie on with a yosemite tuck back on my 8, I build belay's with snapgates, and repair my own friends...none of which are recommended.

I don't use a stopper. I tie with a shortish tail and tuck it back through the centre of the Fig 8. This is really neat and best thing is that after you have lobbed off a few times you can get the knot undone by pulling out the tail which takes the pressure off the knot (the knot having tightened onto the tail when fallen on.)

I guess this is not recommended, but having fallen on this sytem many times (60' being the worst) I'm happy that it is safe.

In reply to top cat:
yeah thats a Yosemite tuckback...we will both suffer the same fate

In reply to SteveoS:

Exactly: for double/triple checking the Figure of 8 and to ensure adequate tail.

In reply to James90: Why NOT tie a stopped knot? it takes what 10 seconds, make thingsd alittle neater and doesn't make things less safe (at the least) so what's the issue?

In reply to krikoman:

Bulk (certainly not neater). Looks naff. Uses up extra rope (rareley an issue, but I have at times had to stretch for a belay!). Gets in the way of a very close clip (ie when the runner is at waist height).

Tuck a short end back: safe, miniumim use of rope, no bulk, undoes better after loading, but never comes 'undone' until you untie. Why use a stopper?

In reply to simondgee: and others

the tuck back or Wagners knot *can* flip if you load the loop (eg in a belay situation)
or hang off a bolt clipped to the loop.

for an example see from 21:30 onwards (specifically 23:10)

http://www.youtube.com/watch?v=9iOM57bYG68#at=1319

I wouldn't.

In reply to lithos: "you know what? Don't do that".

Sound advice!

In reply to James90:
I don't always tie a stopper knot, but always ensure the tail is more than 10cm (more than he width of my hand). If you do tie a stopper, you should ensure it is flush to the main knot, to minimise the small risk of tying in to a belay with the wrong bit of the knot.

Thanks for all the replys.

I guess the general concensus is that its not actually structually integral.

I'd never heared of the yosemite tuck back, and having seen the video will never use that!
Will be checking for crossloading on the fig8 tie in loop at anchors more carefully from now on too!

In reply to lithos:

An odd way to rethread. Surely you loop the tail back over the top of the knot before tucking it back through the knot. Thats what I've always done.

In reply to James90:

James, i think for my comfort I use stoppers, not for falling off and loading along the live rope but for clipping into the loop (as shown that video - minus the tuck back) ie a stopper knot will prevent any rolling (or rather reassure me so i don't have to worry/think/consider about it)

In reply to GrahamD:

no idea, i don't do it.

In reply to lithos: Holy smokes! Ta for that.

But will a stopper on a fig eight prevent it rolling, or make it hold when it has rolled over?

In reply to Jamie Wakeham:

I'd also like to see that tested. In North America, they think you're crazy if you belay from the rope lope due to unfounded paranoia about ring loading. Millions of hours of real live testing in the UK have thus far failed to produce a single known case, but it would still be nice to put some numbers on it.

In reply to James90:
I have to say that although I don't tie figure of eight very often, when I do tie it I finish it with a stopper knot. This is more to ensure that have enough rope, as I believe that was what it was done for in the first place. I have a climber partner that only ever ties in with a Fo8 and yet cant get the length of the rope right, I have seen him finish with everything from a single stopper to two double stopper knots and still have tail left over.

In reply to GrahamD:

Quite so.

In reply to lithos:


Interesting. I've tried to replicate that roll over and can only do it with a knot that starts off pretty slack: much slacker than I would tie in with. I normally use 8.5mm ropes which snug up really well, though for the wee test I've just done I used a new 10mm.

I know where I can get some off cuts of 10mm so will try this cross loading thing between to transit vans: a short sharp pull to take up a bit of slack and then a sustained pull to mimic a fall and then weight of climber suspended. Seems like a better 'test' than on the above clip?

In reply to Lithos:
The knot shown in the video you linked is tied incorrectly...as Graham D has pointed out
...and as TopCat was typing the last observation and suggestion, we were knocking this up after a meeting this evening...
vimeo.com/71379276
...it is for interest and to compare to the american video which suggests a body weight will cause it the knot to roll...we could not get that to happen.
This set up is specifically at moderate forces 4-5KN and the rig is crude (though more realistic than a slowly applied force in a test rig)....it gives an idea
...we could do it with load cell to measure forces and aim toward much higher forces if there was any interest?
Additionally I will try to add some pictures of the actual knots as it isn't visually clear the difference between the death tuck and yosemite tuck in the shots.
(BTW ...The music was selected as it was exactly the same length as the footage!)

In reply to James90:

i do the tuck back. better with gloves on.

likewise i dont do a stopper for the same reason.

i dont think the stopper is inherantly evil, just it allows a margin where i dont think there should be one - tie the fig8 correctly or dont climb till you do.

where i do think the fig8 is bad is with rescue, especially crevasse, confined space, in water and at night where obscured visability and reliance on touch makes stoppers a true bane.

down the wall, unecessary. under compromised conditions, downright dangerous.

but what other people do when im not around is up to them.

In reply to ice.solo: Your post doesn't make much sense to me.


I don't understand what you are saying. You do the tuck back, others tie the stopper. Both require the fig8 to be tied correctly.



If you'd managed to tie a fig8 I reckon you could manage the stopper. And if you really couldn't for whatever reason, just leave a LONG tail on the fig8.


Really? How many folk have died because they used a stopper knot on a fig8?

In reply to Martin1978:

decent points.

a fig8 tied correctly requires no further stopping. the stopper is often there because the tail is too long - so learn the simple tricks for not having too long a tail.
the tuck back is there to help untie the knot, possibly more pertinent in winter.

ive personally rescued a minimum of six people (in 3 different batches) who would have been less at risk and put me less at risk if they hadnt had extra, unnecessary knots in the equation.
ive also assisted maybe a dozen others with injuries injuries off rope where the extra seconds, in 2 cases minutes, in five cases the removal of gloves and in another 5 cases the need of a headtorch could have been better used otherwise.
in one case there was dramatic bleeding, in another respiratory problems.
in these cases no one died, but in all cases a simple fig8 - or even better a tuck back - would have been perfectly adequate unembellished.

in another incident i suffered a facial injury from falling ice and was bleeding significantly and stunned. not having to remove my gloves and fiddle about any more than was necessary was welcome. i still have the scar under my right eye to remind me.

again, i dont care what others do. its their choice. but im sold as to why i do what i do.

In reply to ice.solo: Thanks for the reply, makes more sense now

I agree with you, in rescue situations I'd leave a long enough tail on the knot and be done with.

In reply to simondgee:

Thanks guys, you have saved me the trouble, and in doing the video have gone one step beyond my capabilities!

In the spirit of UKC I must take you to task for not screwing your LH gate properly shut. I mean, what kind of an example is that?

(For the avoidance of doubt, for those who need the reassurance, this is a joke, ok? (bit pathetic I know, but I do have a small sense of humour))

Good work guys, thanks.

In reply to Martin1978:

its all a matter of judging what you do and circumstances etc. i find winter pushes the envelope a bit as to both risk and mitigation (and im a bit fanatical about such things).
thinking always about the emergency implications can be paranoid i suppose, and maybe OTT in some places.

as far as it goes, the tuck back i find best as it reduces the 'f*ckery factor' from most angles; minimizes clipping the tail be mistake, reduces dangly bits, glove friendly, easier to locate by touch and if its not been too weighted can render a fig8 untie-able with one hand. x 2 if using double ropes.

In reply to ice.solo:

I think a lot of folk forget this, and I think being able to adapt and manage risks outside of the norm is what makes climbing challenging and fun.

In reply to Martin1978:


agree totally. the risks being shuffled off to someone else or watered down to hobby level is where i think the true risks start to emerge, and risks that get in the way of the fun you describe.

another thread for another day.

In reply to James90:

Just got to the thread and read through. No reference I could find to the main reason I use the stopper knot with my Fig8. This is that if the knot starts to come loose, it's only the stopper that's doing so (and you can quickly tightening that up when you next get a "hands off" rest) whereas without the stopper, it's the main knot you would first spot coming loose, which would be rather more worrying.

Now, you could say that all knots should be tied tight in the first place, but I'm pretty strict how I tie mine, and still occasionally get one working loose. I've seen a lot of people climb with much looser and/or less well set Fig8 knots than mine, even some people who do this deliberately to provide some slippage to take some of the force of a fall (which I've never understood - I thought that was what we used dynamic ropes for).

Interested to read a few comments that suggest potential dangers in using the extra stopper knot. I'm not sure I get these. Unless convinced otherwise, I'll continue to use a stopper. Just my personal preference of course - just like calling safe on path top crags before tying to the anchors.

In reply to simondgee: that's really reassuring, Simon - good work!

So this would suggest that, under forces up to and beyond anything that should reasonably happen when belaying a second from above them, there is no significant rolling of any correctly-tied variant of the fig eight.

I, for one, would be interested in seeing this carried on with higher forces - I suppose if only to answer the question 'would a crossloaded fig eight roll if subjected to a big factor 2, and does the presence of a stopper knot affect this?'

If you can be bothered, the other statement I'd be interested in testing is the one (mentioned once or twice above) about a stopper knot protecting against an incorrectly tied fig eight?

In reply to simondgee: + top cat

interesting stuff chaps and great video, I too tried messing with it, seems there are 3 ways to tuck the rope back

1) just tuck it back on itself - stoopid (partly tied!)
2) loop it around the standing rope and tuck back (no better really) (Death tuck)
3) go over the knot strands and tuck back from underneath (yosemtite)

I played a little and could get the first 2 to roll only if loosely tied knots. Couldnt really get tuck back or stoppered to roll, nor a well dressed fo8 on its own.

BTW i am approaching this from a teaching stance (i'd not like to teach the tuck back due to the possibility of the 'death tuck' (dtb instead of EDK !) Did you test the EDK to see - cos if that doesn't roll one may deduce from this sample it's safe...

BTW 2 I think that US video was just set up as a demo how it may happen following a similar discussion etc. not a proper pull test.

In reply to simondgee:

nice! (the music that is)
have you seen this before?:
vimeo.com/40767916
can anyone explain the difference between 2 & 3 in this vid?

In reply to daWalt:

interesting ....

difference is the the tuck is either on right or left of the standing end (long end going up in this case)

or another way of saying that the standing end is left of bight and tuck strands
(vs 2) or between tuck and bight strands (3) .

So its where the tuck is threaded through

In reply to lithos:
ta.
I can't work out which I'd have if I tied a fig8 with Yosemity.
I think I'll need to play around with a bit of rope to get it.

In reply to simondgee:

Very interesting. Agree with Jamie, would be good to see significant instantaneous forces tested such as those created in high factor falls.

In reply to simondgee:

Very interesting. Agree with Jamie, would be good to see significant instantaneous forces tested such as those created in high factor falls, although I appreciate that would be hard to do without a rig.

Also, it would be good to see what the stopper adds to this, so testing a plain fig 8, no stopper would be good too.

In reply to daWalt:

Thanks!

Very interesting to be honest its what i really wanted to know at the start of this thread. even when crossloading the fig8 it did not fail with 7Kn of force, By comparison tucking back incorrectly could easily be fatal and even the yosemite tuck decreased the strength by over 10% in the video (but it would have failed much sooner with a shorter tail).

In reply to James90: There are three reasons at least why you must always tie a stopper knot after a double figure of eight:

1. If tied correctly, it locks the double figure of eight. Should you have the misfortune to mis-tie to main knot, then the stopper is a back up device.

2. It acts as a mental check after tying your main knot; when I'm tying the stopper I always know I've completed the figure of eight. Then my mate checks me.

3. It tidies away excess rope. If you have the correct length of tail after tying your first single figure of eight, then you should only be able to tie three loops for your stopper. Any more and it looks like a bag of spanners.

Hope this helps,

James.

1: It has already been concluded i feel that the figure of 8 is sufficient without the stopper. see the video above were they crossload one to 7Kn without a stopper, not something you could easily manage climbing.

2: A figure of 8 is easy to see if it is correct or not, i do not see how a stopper contributes to this.

3: Yes it tidies away excess rope, (and appears to be the safest way of doing so). I already said that i only use a stopper for tidying excess rope when i require it.

In reply to Hans: My partner & I had to rescue someone else's novice second who had tied a F8 without a stopper. He hadn't pulled the F8 tight enough and it had simply shaken open as he was slowly taken up the crag, leaving him untied 50ft up.
A stopper would have kept him safe.

In reply to rogerd: So would tying his figure of 8 correctly in the first place.

In reply to Mike Nolan:

Yes. That's not a stopper knot failure, it's just a failure.

In reply to Jonny2vests:

a correctly tied fig 8 would have sufficed, you appear to be describing incompetance.

I knew when origionally taught that a stopper was expected, it wasn't until i was leading and building anchors that i actually began to question why. Hence this thread

In reply to James90:

How can a fig eight 'shake itself loose'? It's a self-tightening knot - any load in the vertical direction will cinch it tighter, not loosen it. Unless tied with an extremely short tail and in very new, stiff rope, I just can't see this happening. I think I'd be happy to write this off as not having tied the 8 properly in the first place, unless anyone else has seen similar incidents?

But this does represent a repeat of the 'stopper knots will save you if you mis-tie the eight' argument, which reinforces my hope that someone will test some incorrectly tied but stoppered fig eights. I was once told that an eight would hold a fall if only one of the three passes in the rethread were made; that'd be an interesting test too!

Something else whch came to me: we've pretty much disproved (up to 7kN, anyway) that a stopper does anything useful for a fig eight. Often (most times?) when there has been an accident due to a climber mistying their knot, it turns out they were distracted halfway through the tying process. Does adding another phase to the tying-in process increase the chance you will be distracted? Do stopper knots therefore actually make it more likely you will mis-tie, and increase the risk to you? My tongue's only partly in my cheek here.

In reply to Jamie Wakeham:

Myself and a couple of ex-colleagues at the Ice Factor once occupied a slow afternoon with some informal drop-testing on a variety of mis-tied and partially-tied figure of eight knots. Results:

1. No matter how sloppily tied or how short a tail (as short as 1cm), the tail never pulled through the final "pass" on the knot.

2. Even with only 2 passes out of three completed, the knot held a fall every time.

3. With 1 pass out of 3, the knot would hold a light fall at least 50% of the time!

Conclusion - the figure of eight is the Uber-knot. Massively forgiving of sloppy or incomplete tying in a way that the bowline isn't. And it definitely doesn't need a stopper, although this has value as a means of dressing it.

Of course these tests are not authoritative, and it would be interesting to see them repeated on a proper drop-rig.

In reply to rogerd:

In short - bollocks!

JW

In reply to Jamie Wakeham:


Anecdotaly, a number of Austrian Guides will ask clients to untie their stopper knots (on fo8s) as they obscure their view of the important part of the knot!

Last winter I got fed up of stopper-knots loosening-out in snowy conditions, and decided to start doing without, backed up by previous research! In order to do this with an appropriate level of reassurance, I made myself rethread as snugly as possible and aimed for a perfect tail-length of 3-4 inches. Doing this perfectly on demand with 2 ropes is actually quite time-consuming! I reverted..

I also met someone who climbed on an un-stoppered figure-of-nine. Anyone able to comment on that? Easier to untie I suppose but he wasn't a sport-climber.

In reply to Jamie B:

I read somewhere (can't remember so cant reference) that its a stronger knot and easier to untie after load.
Pfff, how strong do you need.
http://www.animatedknots.com/fig9loop/

but agian, the stopper is not a structural part of a Fig9 or a Fig8 knot.

In reply to James90: Just out of interest to people, I was informed by a reliable source that as long as the tail is 6 times the diameter of the rope, no stopped is needed.

At a lot of centres, it is the policy to tie a stopper not, if a customer asks why, I tell them it's to ensure the tail is long enough, otherwise you end up with tails becoming shorter and shorter. Although a short tail may be ok, a tail of around 6cm is bound to be better than one of 1cm!

In reply to James90: just tie a stopper, lol it takes a few extra seconds and its better to be safe than sorry.

In reply to Rockhopper85:

With that logic you'll end up wearing two harnesses.