a new way to tie the alpine butterfly knot?

[alpineer]

@knot rigger post:4

Alpineer:
The two methods you mention of tying the ABK: would those be the hand wrapping, and twisting methods?

Well, yes and no. They are ergonomic adaptations, or re-interpretations, of how the traditional methods are typically depicted. The hand-wrap version is closely related to the “Hybrid” method as it uses one less wrap than the trad.

[Dan_Lehman]

@xarax post:37

13mm is NOT 1/2 inch !
I had pointed out that your calculations were based on an 11mm rope, while now,as you say, even ordinary climbing ropes are getting thinner.
A 7.8 mm rope has half the diameter of an 11mm rope ( so, presumably, half the strength, too ) …

Evidently, you outnumbered yourself! :o :
(11/2 < 7.8, well less.)
You must’ve intended “… the material/volume”,
which presumably implies strength.

In common rope parlance, I think that much of rope
sizing is based on “nominal” sizes, with specifics coming
from weight-per-100’ or whatever. Oddly, in rockclimbing,
ropes now are specified by fractions of a millimeter!!!
This must seem ludicrous to other rope users! (IMO, yes!)
For one thing, just making such an exacting measure
(fraction of mm) seems dubious. (In the good ol’ days,
it was 9 & 11mm, 3/8 & 7/16th inches.)

–dl*

[alpineer]

@roo post:2

I notice that if you accidentally reverse the loop twist of the very first step, you end up with an evil imposter knot for the butterfly loop, namely the half-hitch loop.

[xarax]

@Dan_Lehman post:42

Evidently, you outnumbered yourself! :o :

Lost in the copy and paste… Obviously, I intended to write, and meant, “area”, not “diameter”. THAT is the meaning of the “too”, too ! Strength depends on the cross-section s area, not the diameter, of course.

[knot_rigger]

So I’ve found out this method is (as I suspected) not new, and is know to some folk out there. I have by no means exhausted the possible forums to post this method, but I did find some arborists in the uk to whom this method is know. One guy described learning it back in 98! At an arborist convention.

If I find out more, I’ll post it here

Andy

[eric22]

Hi All,
Last time I tie the Butterfly loop on a vertical line, this time I use the similar method and tie it on a horizonal line, it work out
quite well too. Andy, I have to thanks you, if I didn’t see your video, I may not have these two videos.
https://www.youtube.com/watch?v=xD_DovrBfwc

     謝謝  alan lee.

[knot_rigger]

I’ve posted the results of my break testing of the ABK in the “practical knots” section of the forum.

My conclusion is that the strength of the ABK is symmetrical, there is not a weaker and stronger side of the knot, as proposed by Xarax.

I’ve attached the pdf to this post as well. I have a larger file (400kb), containing pictures, which I can provide to anyone interested. Or I’ll post it on the forum if anyone has a suggestion of how to do it (the max attachment size is 100kb)

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ABK breaking report.pdf (71.1 KB)

[knot_rigger]

An interesting point that knots in smaller line may be more efficient than in larger line.

I may be able to break test some larger diameter line in the future. If I manage to, I’ll post the results.