Moderator: Tim White
Bob Thrun wrote:I regard Wright and Magowan to be the correct definition of Butterfly Knot because they invented the name.
Alpine Caving Techniques has several slips of terminology due to the translation process. The translator was not an expert on knot names.
What ACT calls a False Buterfly is called an Angler's Loop by Ashley, ABOK 1038. The Butterfly Knot is given by Ashley as the Lineman's Loop, ABOK 1053. Ashley credits J. Drew for the name and publication of the Lineman's Loop. Drew had publications in 1912 and 1936, neither of which I have seen, so I cannot tell if he has priority over Wright and Magowan.
Bob Thrun wrote:Wow! Two quick replies. I regard Wright and Magowan to be the correct definition of Butterfly Knot because they invented the name. Alpine Caving Techniques has several slips of terminology due to the translation process. The translator was not an expert on knot names. Perhaps the French prepended the "Alpine". I do not know.
"I have uploaded a sequential photo set on Flickr.
My username in the "People" search field is ursusgummis.
The set is entitled "A Better Way To Tie The Alpine Butterfly".
Bob Thrun wrote:Many refer to a certain mid-rope loop as an "Alpine Butterfly Knot". Others call it a "Butterfly Knot". Is there any difference? The 1928 Wright and Magowan article introduced the name as simply "Butterfly". That article may have been the first publication of the knot too, though with knots it is probable that somebody tied it much earlier. Alan Warild's book, Vertical, has BOTH the Butterfly and Alpine Butterfly! He does not explain the difference. The small drawings in the strength table do have not enough resolution for me do tell the difference.
ek wrote:fuzzy-hair-man wrote:I found it reassuring that using twirly flops I found it actually harder to tie a false butterfly rather than an Alpine Butterfly the false butterfly tries to fall apart so you actually have to hold it together to tie it, which makes me certain I've tied the right one even before I inspect it.
Is this to say that you managed to tie a false butterfly with the finger poke method?
ek wrote:fuzzy-hair-man wrote:If you wanted a false butterfly you could do the half hitch over the loop of a slip knot suggested earlier in this thread.
If you did that, you would have to pay very close attention to the orientation of...everything, to make sure to get it right. I wouldn't particularly recommend this method for actually tying it.
fuzzy-hair-man wrote:No I only use the twirly flop method now, it's just that if you are using the twirly flop method to tie a Alpine butterfly the twists which go in the same direction stay in place without much effort, if you are tying a false butterfly you have to put some extra effort in to make sure the twists don't untwist before you tuck the bight up through the middle.
potholer wrote:fuzzy-hair-man wrote:No I only use the twirly flop method now, it's just that if you are using the twirly flop method to tie a Alpine butterfly the twists which go in the same direction stay in place without much effort, if you are tying a false butterfly you have to put some extra effort in to make sure the twists don't untwist before you tuck the bight up through the middle.
The way I tie it, building the growing knot up in my left hand, it's no harder to tie a false butterfly than an alpine butterfly, though I never tie false butterflies except when teaching knot tying, to show people what the wrong knot looks like.
I don't even tend to use the alpine butterfly much anyway!
knudeNoggin wrote:In what rigging situations is a multi- (bi-) directional eyeknot needed,
and not merely a (single) "directional" one?
knudeNoggin wrote:In what rigging situations is a multi- (bi-) directional eyeknot needed,
and not merely a (single) "directional" one?
(emphasis mine)xcathodex wrote:(1) To isolate a section of rope with a damaged sheath - here the value isn't that it can be loaded in multiple directions but, rather, that it can be loaded normally as a mid-line knot. If the rope is still in reasonable condition, the bight also makes for a handy safety loop to clip a cow's tail into when passing the knot.
xcathodex wrote:I'm sure more experienced vertical cavers than I can think of more. I used one last month to pull slack out of the line between two pitch heads rigged with a single rope (essentially a rebelay), as I wasn't particularly comfortable with the bolt at the lower pitch; if it failed, I wanted to make sure there wasn't any unnecessary slack between my falling body and the single remaining bolt above.
ek wrote:If the rope is sufficiently damaged to warrant tying off the damaged section (and thus complicating progression considerably), it's too damaged to clip into that section. Tie another loop knot next to it and use that one.
xcathodex wrote:I'm sure more experienced vertical cavers than I can think of more. I used one last month to pull slack out of the line between two pitch heads rigged with a single rope (essentially a rebelay), as I wasn't particularly comfortable with the bolt at the lower pitch; if it failed, I wanted to make sure there wasn't any unnecessary slack between my falling body and the single remaining bolt above.
EK wrote:I remember your having told me about this. Thinking about it in the context of this discussion, it occurs to me that this may have been a situation where tying a false butterfly (due to its shock-absorption) would have been even better.
ek wrote:(emphasis mine)xcathodex wrote:(1) To isolate a section of rope with a damaged sheath
... the {eye} also makes for a handy safety loop to clip a cow's tail into when passing the knot.
I strongly disagree with the idea that it is OK to clip into the loop in this situation, ever.
If the rope is sufficiently damaged to warrant tying off the damaged section (and thus
complicating progression considerably), it's too damaged to clip into that section.
I would never use it as an endline knot though.
xcathodex wrote:Fair enough. In practice, a worn sheath segment is isolated before it's anywhere near this bad; I'd isolate a bad "fuzzy" or partial tear (haven't needed to, yet) and wouldn't think twice about clipping into the loop. Likewise, in practice, if I am ever ascending up after a caver above me has isolated a very badly frayed rope segment, but not left a secondary loop -- a situation where I'd need to pass the butterfly before being able to tie another loop knot below it -- I would probably choose "sketchy bight of frayed horror" over "no secondary point of attachment while I transfer my ascenders past the knot." However, what we do in practice isn't always the best practice, and you are correct that advocating a sloppy practice is an exercise of poor judgment.
knudeNoggin wrote:I recall someone once remarking about the idea of isolating a damaged part
of rope, remarking that, as most knots are around 60% or so, the rope would
have be badly damaged for tying it off to be stronger.
knudeNoggin wrote:But here I'll suggest that there is a significant difference between one's
hanging on an eye w/damage and just leaving the part in-line: for
starters, there are two legs to the eye, so the tension is half of the
suspended, static load of one climber; whereas inline its subject to
some greater force of ascending and an accident. Esp. if there is
substantial rope undamaged, you're looking at 1-2+ tons of strength.
ek wrote:I would never use it as an endline knot though.
knudeNoggin wrote:Although, of course, that's how it's tested, qua eyeknot.
But here you'd have to confront its asymmetry head-on
(or ignore it blindly), and choose which way to form it.
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