mid rope Y hang - prefered knot ?

[cap n chris]

What he said.

 

[Chocolate fireguard]

That sounds like a good alternative to what I do.
Anything that brings the traverse line into the Y knot on a wide hang.

 

[Simon Wilson]

What are the downsides to the fusion knot (other than it isn't widely used [yet])?
It is a 'stable' knot. You don't have to worry where you clip it. The loops are easy to clip. It is easy to tie.

https://www.youtube.com/watch?v=-5-YbRxceiY

I tried to replicate this myself and whilst the knot [BotB] slipped it tightened up so much that it never ever went all the way through, then the knot was dressed correctly.

fusion knots I have been informed that these have been tested and suffer the same slippage as a bowline on a bight
I have been informed that if you tie a bowling on a bight from making 2 overhand knots then this does not slip.
ultimately as long as knots are tied correctly and dressed correctly then there should not be any issues,

In fact, now I've tied it, I can report it's a lovely little knot [fusion]  (and I've also managed to replicate the Bowline on the Bight problem). I have no doubt the French have done plenty of drop testing before The French Caving School has actually come out and recommended the Fusion Knot.

Damian appears to be assuming the FFS tested both knots sufficiently and that would seem to be a reasonable assumption but is that assumption correct?

So, does the fusion knot solve the slipping problem and is it the best solution?

The fusion knot seems to have an advantage over the 'double figure of 8 on the bight' in that it is easier to adjust.

 

[mikem]

Presumably the only downside I can think of for an AB hang is if the loop bolt fails then there could be a substantial drop for someone clipped into it - if there is say a 1m long loop then you could take a 1m (+ swing) fall if you are clipped into only the loop (as your cowstail slides along it). An knot in the loop near the Y-hang would stop this. I would also not be at all surprised if a snapgate managed to unclip itself from the loop in such a fall.

Wouldn't you be attached at another point? Either 2nd cowstail or ascender/descender.

Mike

 

[cap n chris]

With a lot of UK caves due to be rigged and used by a large number of visiting cavers, is there a template for the knots which riggers should use as reference so rigging is done as safely as is practicable? e.g. leaving an HMS carabiner on a BotB isn't going to work because people will doubtless collect them as they go, thinking someone has left it behind absent-mindedly.

 

[mikem]

I would prefer them to use knots they are confident of tying securely...

Mike

 

[Simon Wilson]

With a lot of UK caves due to be rigged and used by a large number of visiting cavers, is there a template for riggers to use as reference so rigging is done as safely as is practicable? e.g. leaving an HMS carabiner on a BotB isn't going to work because people will doubtless collect them as they go, thinking someone has left it behind absent-mindedly.

I think we need to sort this problem out before Eurospeleo. There is a guide for people who are rigging for Eurospeleo but it doesn't recommend any particular double loop knot. I think we need to decide whether or not to advise against the BotB and suggest another knot.

There appears to be three choices for another double loop knot.

I don't like the double bowline on the bight because the stacked up loops look a mess after they are loaded.

So for me the choice is between the D8otB and the fusion. The D8otB is nicely symmetrical so you can see that it is tied and dressed correctly but it is more difficult to adjust. For normal caving adjustability might be a consideration but not for Eurospeleo when riggers should have all the time to do text book rigging. So at the moment I'm tending towards the D8otB for text book rigging at Eurospeleo.

But I still want to learn about the fusion knot for everyday caving.

 

[mikem]

Damian appears to be assuming the FFS tested both knots sufficiently and that would seem to be a reasonable assumption but is that assumption correct?

So, does the fusion knot solve the slipping problem and is it the best solution?

The fusion knot seems to have an advantage over the 'double figure of 8 on the bight' in that it is easier to adjust.

They certainly tested it for the slippage problem of the BotB & decided that the fusion knot was a better option - stating that it "was very widely tested in the latest drop tests" & "can be used without a stopper knot":
http://efs.ffspeleo.fr/ZZ.OLD.EFS/documentation/video/noeud-de-chaise

The other advantage is that the loops are easier to clip as they do not close up as much as the bunny ears when loaded.

Mike

 

[Simon Wilson]

Bunny ears?

 

[mikem]

Bunny ears = D8otB.

Mike

 

[Simon Wilson]

I think the term might have come to be assumed to mean that by some but some take it to mean any double loop knot. I think the term is best avoided but unfortunately it's use seems to be increasing.

 

[David Rose]

Honestly, what's not to like about bunny ears figure 8s? I mean, surely they are the safest knot, and the hardest to get wrong - and they're not THAT hard to adjust. And you can tell instantly by looking at them whether they've been correctly tied - unlike bowlines on the bight, which deform under load so this can be quite tricky.

 

[mikem]

I have only ever heard of the figure 8 being referred to as "bunny ears" & it has been for years in climbing - the other knots give a more circular shape (quite unlike a rabbit's).

Mike

 

[Fulk]

So, I guess we could call the DBoTB a cat's ears, the fusion knot a  . . . I dunno, Donkey's ears . . . etc.

 

[Simon Wilson]

I have only ever heard of the figure 8 being referred to as "bunny ears" & it has been for years in climbing - the other knots give a more circular shape (quite unlike a rabbit's).

Mike

Sorry Mike, I just find it a slightly ambiguous term and without being too pedantic I think we need to be clear about what knot we are referring to.

 

[topcat]

I've heard the Pile Hitch called a Polish Knot, can you confirm if this is what you mean?
http://www.peakinstruction.com/blog/knots/pile-hitch-how-to-tie/

Yep, that's it.

 

[Simon Wilson]

Honestly, what's not to like about bunny ears figure 8s? I mean, surely they are the safest knot, and the hardest to get wrong - and they're not THAT hard to adjust. And you can tell instantly by looking at them whether they've been correctly tied - unlike bowlines on the bight, which deform under load so this can be quite tricky.

Yes to all that and Mark Wright recommended the 'double fig8 on the bight' on the fusion knot thread.

 

[todcaver]

on the subject of safest no slippage knots to use ,,
So far the candidates are bunny ears  or
Figure 8 to one bolt - alpine butterfly equalize the other bolt  ,
Can anyone confirm if the Bobob or fusion  knot slip under incorrect loading ??

 

[Alex]

Back to the original question as I wanted to reply yesterday...

For me it all depends on the position of the Y-hang. If the final bolt on the traverse is part of Y-hang and is basically going in the same direction of the traverse then I will just use another alpine. If however, that there are two bolts at 90 degrees to the traverse then I will generally tie bunny ears as its the easiest and quickest method as well as being relatively safe.

The team are starting to use fusion knots as they are stronger and are safer, but for normal caving I personally do not bother as I don't think they are as easy to adjust as bunny ears and the knot uses up more rope.

 

[JasonC]

Honestly, what's not to like about bunny ears figure 8s? I mean, surely they are the safest knot, and the hardest to get wrong - and they're not THAT hard to adjust. And you can tell instantly by looking at them whether they've been correctly tied - unlike bowlines on the bight, which deform under load so this can be quite tricky.

They get my vote too, fwiw.  It was put to me that a BoB uses less rope - true, but it's rare to be that desperate to economise.
I was recently shown how to tie the fusion (which I'd been unable to do from videos ) and it's fine, but I can't see any compelling advantages over Bunny Ears (or double-fig 8 on the bight you like).  There's a lot to be said for sticking with what you're familiar with.  Also BE has the advantage of self-adjusting if the two hangers are at different heights, admittedly not a usual situation.

Another refinement I was introduced to recently was to take the traverse line up right up to one of the Y-hang bolts, before tying the Y-hang, resulting in an extra rope loop.  The idea was to give an extra way off if someone got into difficulties going up, and would help in a rescue.  Not worth the extra faff normally, but might be worth doing for Euro Speleo