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Y-hang

hannahb

Active member
For a Y-hang with the traverse going to the "bottom" of the Y, is it better to tie a bunny ears rather than two alpine butterflies, with a long loop for both butterflies?

Is there a reason not to tie two alpines close together with long loops?
 

pwhole

Well-known member
If it's how I think you mean, I don't think the load would be truly equalised between the two anchors - you may end up with one knot leaning toward one anchor more than the other once it's loaded due to small variations between the two alpines. I suspect due to the awkward passage of the rope through all that it may not be that strong either. A well-tied and equalised bunny knot is very strong.
 

Pitlamp

Well-known member
I'd be the first to admit I'm not very clued up on the finer details of SRT - and that there are folk on here who do it daily for a living, who know far more. SRT is a means to an end for me; as long as I can get up and down in one piece, often with a load of gear for some project somewhere, that'll do.

Pwhole definitely knows his stuff (we're in the same club) and I think he makes an important point that we should always strive for the safest option. But - how often are there accidents caused by rope failure (in a non abbrasion situation)?
 

wellyjen

Well-known member
If one, or both of the anchors are so marginal that you are worried they won't take more than half the load, you probably wouldn't want to use them anyway. I'm usually more concerned with positioning the Y so the rope is going to miss any rub points. If that loads one side, more than the other, that is fine by me. If the more heavily loaded side were to fail, the load would transfer to the other with a minimal shock to the anchor, rope, or caver, which is the primary purpose of a Y hang.
Two butterfly knots, close together would work fine, but be harder to adjust, if you need to feed rope through both knots to get the hang to your satisfaction. A fusion knot, in particular is much easier to adjust than other bunny ears style knots. Bowline on the bight was easier still, but they are frowned upon now.
 

andrewmcleod

Well-known member
A fusion knot or a bunny ears is much superior to a pair of alpines, long or short, for most Y hangs. A fusion has the advantage that it is easier to clip in to the loops than a bunny ears.

Two Alpines is a bit of a mess.
- It looks messier and why use two knots when one will do?
- The bit of rope between the two loops is not safe to clip, because bolt failure on the pitch-side Alpine could result in your carabiner sliding over the knot and you falling down the pitch.
- The bit of rope between the two Alpines also creates a 'gap' in the rigging. For a larger Y-hang with one short Alpine, this means it can be difficult to get from the bottom of the knot to the high-up traverse line or vice versa (and you end up doing stupid things like prussiking up the leg of the Y hang).
- You can't clip both loops with one cowstail. Unless the loops are both long and/or the Y-hang is small, you may not be able to clip both loops even with both cowstails. This means in the event of bolt failure on your chosen loop you will experience a shock load as you fall to the bottom of the loop (which would now be hanging down).

A double loop knot is nearly always 'superior' (safer to pass, easier to pass) than a pair of Alpines.

The disadvantages are that a double loop knot uses _slightly_ more rope for a large Y-hang, can be slightly slower to tie for some people, and requires you to know more than one knot to rig a cave.
 

mikem

Well-known member
Two Alpines is a bit of a mess.
- The bit of rope between the two loops is not safe to clip, because bolt failure on the pitch-side Alpine could result in your carabiner sliding over the knot and you falling down the pitch.
The main thing against it is this. However, there are situations where you want the traverse line to come in higher & prussiking up that section, whilst awkward, is acceptable.
 

wellyjen

Well-known member
The main thing against it is this. However, there are situations where you want the traverse line to come in higher & prussiking up that section, whilst awkward, is acceptable.
Yes, it does happen. A wide rift, where the Y knot ends up low down, but the foot holds you are going to need for the traverse are high up.
 

Steve Clark

Active member
Main disadvantage seems to be not being able to clip both loops with a single cowstail, as noted above.

Similar problem clipping in a single carabiner to create a rescue master point. You really wouldn’t want to put that on the rope between the alpines. Clipping just one of the loops gives a big fall in the (unlikely) event a bolt fails with the 2-3x rescue load.
 

JoshW

Well-known member
Main disadvantage seems to be not being able to clip both loops with a single cowstail, as noted above.

Similar problem clipping in a single carabiner to create a rescue master point. You really wouldn’t want to put that on the rope between the alpines. Clipping just one of the loops gives a big fall in the (unlikely) event a bolt fails with the 2-3x rescue load.
There’s a way of clipping a carabiner into the knot of an alpine butterfly to create a master point (obviously not possibly under load, but if placing ‘king crabs’ works well)

Disclaimer: there is a way of doing this right and a way of doing this very wrong, seek appropriate advice and training before trying out obviously…
 

cap n chris

Well-known member
Be like Dave. CaveRopeGod. Pic c1986.
IMG_20230828_095005.jpg
 

mikem

Well-known member
There’s a way of clipping a carabiner into the knot of an alpine butterfly to create a master point (obviously not possibly under load, but if placing ‘king crabs’ works well)

Disclaimer: there is a way of doing this right and a way of doing this very wrong, seek appropriate advice and training before trying out obviously…
If you're worried about it beforehand, tie another butterfly in the loop, so cowstail krab will be retained near the knot...
 

hannahb

Active member
Thanks all. I favour bunny ears for a low Y-hang, but it came up in discussion yesterday and we weren't sure why it would be a "problem" to tie two alpine butterflies if that was the knot you knew.
 

JoshW

Well-known member
If you're worried about it beforehand, tie another butterfly in the loop, so cowstail krab will be retained near the knot...
Another valid option 💪🏼

I’ve also taken to adding an additional longer alpine butterfly into the traverse line that can be used as the ‘last’ attachment point for long cowstail to test out descender with reduced chance of getting strung up on it, and easier to release than clipping into both loops of a knot at the pitch head when loaded.

(Apologies for slight derailing of thread)
 

andrewmcleod

Well-known member
An example that comes to mind of when things are awkward is that awkward pitch head in Stream Passage Pot where the bolts are low and the Y hang is well below the footholds. Options include:
1) using Alpines and having to prussik up the leg of the Y hang (and even more difficulty on the way down)
2) use a Y hang from the last two bolts on the traverse side and a deviation on the opposite wall - can be very awkward as it is often a high angle deviation
3) use a Y hang off the last two bolts on the traverse side and rebelay from the last bolt on the traverse side and the opposite wall (so you have effectively an access rope to the low wide Y hang) - can often mean you have a free-hanging rebelay (and you use one bolt twice).

Fundamentally you can only do so much with awkwardly placed bolts (and often the bolter could only do so much with awkwardly placed good rock)...

But this sort of thing is the exception rather than the rule. 95%+ of Y hangs are better with a loop knot.
 

Fjell

Active member
The answer is you can use any knot your like, it’s just convenience. You could rig every cave with overhand knots without any genuine concern beyond having to undo them. If you believe knot strength is an objective problem, you are using the wrong rope. My main criteria is that the knot cannot fail if a loop is cut. I rig almost everything with fig 8’s and butterfly’s, it’s simple and reliable and easy to teach.

It’s startling how many people can’t tie a bowline reliably, so maybe best not to bother.
 

Cantclimbtom

Active member
I like bunny knots and use them as first choice for the average y-hang as they are quick and easy and compact.

But back in the day... I worked in access for a few years, during that time we pretty much only ever used fig 9s and alpine butterfly knots. Quite possibly I never once used someone else's or rigged a job with bunny knots. There was an [untrue] belief held by many at the time that if the rope snapped in one bunny loop/anchor it'd pull through the knot and it had no redundancy. Testing disproves that theory.

We only used fig 9 and butterfly and somehow survived 🤣.

Use what you want, but I think the bunny knot for a y-hang where anchors are reasonably close together is the quickest and neatest solution and easiest for someone else to check by eyeball.
 
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