UKC

Hi all

Looking for some advice on alpine butterfly. It seems like a good knot to connect abseil rope to a master point as it is easy to untie with the tail connected as backup in case the alpine butterfly fails in some way. I usually use a fig 8 because it is what I learnt, but can be righ pain the ass to untie after a lot of weighting.

So, is it safe to use when correctly tied or is there risk of failure in some way that the fig 8 isn't? Searching the internet only surfaced information about its use when equalising 2 anchor points. Nothing negative or no no's.

In reply to druss:

fairly standard caving Y - figure of 8 & alpine butterfly

https://sites.google.com/site/musccaving/map/caving-tec/Rigging-Knots/alpin...

In reply to druss:

Talk to a caver about the magic rabbit knot. This is an alpine butterfly tied in an ingenious way to equalise anchors. A slip knot with a twist above it is my best description, a bearded photophobic troglodyte will be along soon with a much better description.

In reply to EdS:

Thanks. I'm familiar with that setup but sometimes the situation is more suited to create a equalised anchor using slings/cordlette and tieing the ab rope using a figure of eight (purple rope) like at the link below.

https://www.google.co.uk/search?q=abseil+rope+figure+of+8&rlz=1C9BKJA_e...

Instead of the fig 8 in the above picture, can you use an alpine butterfly instead with a tied-off tail (no tension)?

In reply to druss:



The Alpine Butterfly is easier to untie when rigged as per other's have mentioned - a Y hang, where the loop and a leg/strand are both loaded. Your suggestion of just using the loop with the leg/strand tied off (to what, if not an anchor forming a Y hang?) would end up being just as uneasy to untie.

If what you're after is a loop knot, that is easy to untie after being weighted, then the standard response would be figure of nine loop.

There is load data for the AB when used as an end loop. It's less strong than a figure of eight loop. (It won't break but some people get wound up about such stuff).

In reply to druss:
A good question. An Alpine Butterfly is certainly slightly easier to untie and I do regularly use it in the sort of situation you describe but there are also plenty of others options.

Figures of nine and ten work well, as does a Double Figure of Eight but another cunning option is the dedicated easy release knot formed by tying the Double Figure of Eight but then clipping all three loops rather than passing the single loop back over the knot (e.g. stop at step 3 in
https://www.climbing.com/.amp/skills/learn-this-the-double-figure-eight-kno... and clip all three loops). For any very high tension system, this is easily the best option, however just for general abseiling I have to admit I normally just stick with a well dressed fig8 as it is then really clear that it is tied correctly and it is confidence inspiring to others users as the rigging is simple and obvious.

In reply to druss:

Thanks for the information and POVs.

In reply to druss:




Yes.

In reply to druss:

I know a figure-of-eight follow-through is annoying to untie after it's been loaded, but remember the advantages too. It's particularly easy to do a visual inspection and be categorically certain it has been tied and dressed correctly.

An alpine butterfly will do for your purposes, and you might want to look into the Yosemite bowline too (long tails are your friend either way), but I've never heard of an incorrectly tied eight escaping everyone's attention.

In reply to druss:

fig 9 is much easier to untie after load -
only downside is it's too complicated (at least for me) to tie by the re-thread method......