Author Topic: ABoK #1047 variant - Karash Double loop - opinions?  (Read 8810 times)

agent_smith

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ABoK #1047 variant - Karash Double loop - opinions?
« on: December 29, 2008, 11:59:55 PM »
While scouring the net for every last drop of information on Bowlines, I stumbled upon this site:

http://www.karashknot.com/7.html

Thought I'd bring it to the attention of the IGKT forum.

Has this knot been known to and analysed by the IGKT before?

I am make no opinions at this point in time - I am merely the messenger!


agent smith

Dan_Lehman

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Re: ABoK #1047 variant - Karash Double loop - opinions?
« Reply #1 on: December 30, 2008, 05:34:42 AM »
While scouring the net for every last drop of information on Bowlines, I stumbled upon this site:

http://www.karashknot.com/7.html

Has this knot been known to and analysed by the IGKT before?

It was submitted to the IGKT quite some time ago, and was found to be a decent-looking
option to the Bowline on a Bight; it is essentially the corresponding twin-eye knot to
what Hansel & Gretel's EKFR call the "Twist Bowline" as it the BoaB to the Bowline.
To my classification, it's not a bowline (and certainly not a Fig.8 variant--nevermind it that
knot appears amidst one tying method) but an anti-bowline or a Crossing-knot-based eyeknot
It has received some discussion on-line on a the NSS's (cavers) forum OnRopo--to wit:
forums.caves.org/viewtopic.php?f=5&t=6852&st=0&sk=t&sd=a&hilit=karash&start=0

There are two test reports, showing results of tests on 4 different ropes (of 3 brands);
the rough breaking strength is 70%, quite good (though we can wonder if the knot
was tied --rather loaded-- exactly as Mike Karash presents it at his site (with
load on the pulling-away-from-parallel-part end (vs. "pulling-into..." one)).  There is also
data from some comparative testing of the commonly known (but not only possible)
twin-eye ("bunny ears" (w/o the rabbit hole!)) Fig.8 knot and the Bowline on a Bight.
(both of which, as tied-WITH-a-Bight knots have the "Which end is loaded?" question).

This knot is another example of the potential to use the Insert-eyebighTip-into-nub-and-backflip-it
method of making twin eyes, even if Mike's tying method disguises it (by doing so in a roundabout
way, via another, well-known knot).

--dl*
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DerekSmith

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Re: ABoK #1047 variant - Karash Double loop - opinions?
« Reply #2 on: December 30, 2008, 01:58:45 PM »
Perhaps this is your Eureka moment.

This knot - whatever it is called - does not have the 'G' Spot !!

Scott McCrea calls it "bowline-on-a-bight with a twist." and that is a very apt description, because the twist is the key to ridding the bowline of the 'G' Spot.

Forget also for one moment the Tied in bight (TIB) double loop construction and the novel way of forming it from an '8' and just concentrate on the twist.

Tie an ordinary (i.e. single) bowline - make the loop by putting a twist into the rope in readiness for the WE to be passed up through it - but before passing the WE through, twist the loop a second time, then make the rest of the knot as usual, pass the We up through the twisted loop, round the SP and back down through the loop, dress and set.

THE 'G' SPOT IS GONE.

The load on the SP now enters the knot and makes a full turn around the two legs of the bight before coming back around the SPart and off to make the eye.

BUT DON'T STOP THERE

This time make the double loop as if you are going to start the EBDB, but before threading the WE, twist the double loops, then thread the WE up, round and down, dress and set.



   

FINALLY TRY THIS

the EBDB with a twist, but this is probably unnecessary because the twist not only destroys the 'G' Spot, it also provides a self 'Back Lock' mechanism

Up till now, I would have stated that in my opinion, the EBDB was far superior superior to all the other bowlines, but now I think the Double Loop Twist Bowline is the bowline to beat.

But that is just my opinion based on the structural identities - now we have to substantiate the claim and prove it.

If it does prove to stand up to the challenge, it will need a name.  But before we go any further on naming, lets have some serious testing and abuse of this knot posted here for peer review.  Then we might be able to hold up The Grail.

Derek

agent_smith

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Re: ABoK #1047 variant - Karash Double loop - opinions?
« Reply #3 on: December 30, 2008, 03:46:27 PM »
Very interesting discovery!

Quote
Tie an ordinary (i.e. single) bowline - make the loop by putting a twist into the rope in readiness for the WE to be passed up through it - but before passing the WE through, twist the loop a second time, then make the rest of the knot as usual, pass the We up through the twisted loop, round the SP and back down through the loop, dress and set.

THE 'G' SPOT IS GONE.

The load on the SP now enters the knot and makes a full turn around the two legs of the bight before coming back around the SPart and off to make the eye.

But, if I have tied this first structure correctly, it is susceptible to ring loading. I grabbed each eye leg and jerked it apart a few times before it fell apart...

EDIT 1: I retied this first (single loop version) in cowboy fashion so the tail lays outside of the eye...and I found it to be resistant to ring loading.

EDIT 2: Having another closer look at its structure, it appears (to me) to be based on a munter hitch...placing the extra twist creates the munter hitch form.

EDIT 3: Re-tied (1st) non cowboy variant but added a binding turn to place 3 rope diameters inside the nipping loop..this works very well and it looks, feels and is secure and stable.

Will photograph the Munter Bowline with end binding loop tomorrow and upload... have good 'tacit' feeling about this one...but is hard to say whether it is any stronger than other already discussed forms.

...

Am now tying and playing with second variant with double loops...

Okay, second variant with double loops is resistant to ring loading...that's good. Will now place end binding loop to create 3 rope diameters (ie in same fashion as DL's EBDB)...



Just tried the end binding trick it and it works well - seems very secure. The binding turn went round the eye leg before inserting into the nipping loops.




agent smith
« Last Edit: December 30, 2008, 04:25:49 PM by agent_smith »

Dan_Lehman

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Re: ABoK #1047 variant - Karash Double loop - opinions?
« Reply #4 on: December 30, 2008, 11:43:14 PM »
I was content to leave the Search for the Holy Grail (of rockclimbing tie-in eyeknots)
to the Bowline family (and of this, to the pure "Bowline" sub-class, excluding what I
call the "Anti-Bowline" subclass of "Bowlines":  where the tail reenters the knot from
the opposite side of the **quintessential/definining qua "bowline"** nipping loop).

But here you're stepping outside of that.  And this knot doesn't deserve, on structural basis,
the name "bowline"--nevermind what gift of nonsense Hansel & Gretel gave to us.   Firstly,
there is no nipping loop, really, but a Crossing Knot (above, with an extra turn); secondly,
the end reenters the nub from the side opposite to that that the SPart lies on in crossing
itself (Derek's GeeSpot).

Quote
Scott McCrea calls it "bowline-on-a-bight with a twist." and that is a very apt description,
 because the twist is the key to ridding the bowline of the 'G' Spot.

??  Nonsense on the long-winded quite wrong-headed moniker:  a BoaB is (1) made "on a B."
and (2) has twin eyes--now, do you see how apt this is?  Not at all.  And "apt because ..." is
a non sequitur IMO:  let's think about what the essence of a Bowline is, twisted or unharmed.

> The GeeSpot is gone.

It was much a myth in significance re the Bowline.  But, no, so far as I see it, there is such
an offending crossing point writ large in this knot, where the SPart's flow into the eye crosses
(u-turns) around the SPart, which bears over it.  Here, too, under load the SPart can change
the incline of this plane of crossing such that it bears ever less severely against the other part.

---------

The version presented above by Derek is a dressing and a turn different from what I presented
as the "Locktight I", a knot whose discovery came with the new millennium (Y2K, 2000 --and I like
my New M. to start here, not 2001, thank you all the same).  To get here from there, you simply
move the eye-end of the SPart coil up (as D. presents it, eye-down) around it, so that the SPart
now reaches all the way to the lower/eye side, and then wraps back up around itself, and then
makes the hard-turn exit en face de collar--very Strangle -like, eh!?  yes, the point.

I've fiddled some versions of this, which all extend H&G's so-called "Twist Bowline" by having one
or more *overwraps*, like a Strangle (and for the same effect--slack security).  They seem to work
airly well, with the back-door secret for loosening to untie being the collar'd end & hard bend of the
SPart-side eye leg--which is bent so sharply that some loosening through the collar nevertheless
doesn't really enable this end of the coil to feed back into and loosen it, as the material just doesn't
flow around the hard turn.

My image of it used to reside on Dan Britton's Knot Knowledge  site, which is now gone.

The Locktight seemed to have what D. would luv to call a GeeSpot issue:  after hard loading
(by me via pulley, e.g.), there was a pronounced point of compression in the SPart at its turn
into the overwraps.  But this I think can be ameliorated by careful positioning of the end, in
anticipation of the heavy SPart draw, using a Cowboy collaring, and maybe with some mild
twist of SPart  and re-entering tail --though this introduces complexity beyond what
most users can be expected to master (and maybe excessive material constraints).

No, no, no:  NOT any "Munter Bowline".  We really shouldn't be corrupting "bowline" as a
concept into meaning what it has occasionally historically seemed to mean, simply "eye knot".
It's bad enough that others have grabbed onto "bowline" apparently as a means to credibility.
Let's try to figure out that "bowlines" should share an essential component, what that is,
and excise things from the set that lack this.  I exclude the Crossing-knot (Munter) base
because the eye-side doesn't pull directly into the essential loop (1 or more turns).
(There is Ashley's "Carrick Loop" (#1033) as a problematic case:  it's quite *bowline* unless
the tail is pulled tight to collapse the eye-side exit back around the SPart into Crossing-knot
form--where to delimit the two cases here!?)

--dl*
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