Kalmyk alternative, non jam?

[alanleeknots]

Posted by: agent_smith
? on: June 10, 2021, 09:23:11 AM ?Insert Quote
per Andreas:
Quote
About jamming, maybe Allen can clarify. My observation was that the two knots are not equal in
regards to ease of opening.
You know that there is nothing to stop you from experimenting with these types of 'anti' Bowlines yourself.
You will find that they are resistant to jamming.
What I am saying is..."Why not prove this for yourself?"

I am not entirely clear what Alan Lee was attempting to do (or prove).
All 'Bowlines' can easily be loosened by starting at the 'collar'.
Alan appeared to not really try - watching the video gave me the impression that he was more interested in checking other segments of the knot core?
I honestly don't fully understand what his intentions were?

As stated, I've loaded the slipped and non-slipped versions of these 'anti' Bowlines and could not induce jamming (and this was right up to the MBS yield point).
I used EN892 human rated rope - but, that shouldn't make any difference.

Anyhow, I'm sure that Alan will weigh-in with his comments...

   I am not entirely clear what Alan Lee was attempting to do (or prove).
                     I honestly don't fully understand what his intentions were?
                     I don't like it these two sentences at all.

[alanleeknots]

To Andreas and Alan,

The jamming mystery is now solved.

The so-called 'Kalmyk loop' - found at illustration #97 in Lev Skryagin's knot book and also at this link: https://en.wikipedia.org/wiki/Kalmyk_loop  is topologically the same as an 'anti Bowline',

Interestingly, #97 Kalmyk loop has an induced twist in the collar + legs of the collar - it is rotated.
This geometry is (in my view) 'forced' - and it pushes the tail upwards so that it is situated outside of the eye.

It does indeed appear that this 'forced' geometry affects its jamming properties.

However, if you rotate/twist the collar and its legs so that the tail is now inside the eye (which is a more 'relaxed' dressing) - it becomes totally jam proof.

To advance a theory as to whats going on:
When the collar and legs of the collar are rotated to 'force' the tail to a position outside of the eye, it affects the operation of the nipping structure - which now acts like #206 Crossing hitch.
The nipping structure is not able to rebound - it continues to contract.
The SPart also presses against the tail which further occludes the nipping structure.

Summary:
The 'anti' Bowlines where the collar and its legs are dressed in a more 'relaxed' state are totally jam proof.
Induce a rotation/twist in the collar to 'force' the tail upwards so that it is outside of the eye - and it now causes jamming.

I'll post some pictures when I get a chance.

            Now you are talking.

[Kost_Greg]

Hi Andreas, that's the cowboy version of your virtual bowline.

I realize that the tail slipping, as you did, does not support the tibness this time.

However, the very next illustration, with the figure eight incoming eye leg structure, leaves no remnant knot when untying, supporting the TIB property.

I have placed the yosemite turn close to the nub behind Spart, for in this geometry,  is more compact and it does not affect the form of the knot at heavy loadings.

[agent_smith]

Hello Alan,

Withe regard to your comments:

I don't like it these two sentences at all.

Now you are talking.

My words were not intended to offend you Alan.
I'll restate my position again:
I honestly was confused by the jamming results.
It was the first time I saw your video - and the prevailing view was that anti Bowlines don't jam.
So you video took me by surprise...until I realized exactly what was going on.
The so called 'Kalmyk loop' is topologically identical to an anti Bowline and so I assumed it would also follow the same general rules.

Its incredible that a simple twist/rotation of the collar upsets the jamming properties.
In my opinion, the 'Kalmyk loop' is a 'forced' dressing state, and it upsets the nipping structure, which can no longer 'rebound' when load is released...

Anyhow, the mystery is now solved - and I will have to go back and update my Bowlines technical paper to describe how a simple rotation/twist of the collar completely upsets the jamming properties of anti Bowlines.

[Andreas]

Thank you tsik for clarifications   )   it's better like this in  cowboy fashion. But can not open with one tuck anymore...

I found that the same tie can be dressed into the knot shown below. I tried the same with the  cowboy tie. But I prefer the one shown.
This one seems to be more  compact and secure than the initial dressing.
It might jam ... Might not   )

[Dan_Lehman]

To Andreas and Alan,

The jamming mystery is now solved.

The so-called 'Kalmyk loop' - found at illustration #97 in Lev Skryagin's knot book and also at this link: https://en.wikipedia.org/wiki/Kalmyk_loop  is topologically the same as an 'anti Bowline',

Interestingly, #97 Kalmyk loop has an induced twist in the collar + legs of the collar - it is rotated.
This geometry is (in my view) 'forced' - and it pushes the tail upwards so that it is situated outside of the eye.

It does indeed appear that this 'forced' geometry affects its jamming properties.

However, if you rotate/twist the collar and its legs so that the tail is now inside the eye (which is a more 'relaxed' dressing) - it becomes totally jam proof.

To advance a theory as to whats going on:
When the collar and legs of the collar are rotated to 'force' the tail to a position outside of the eye, it affects the operation of the nipping structure - which now acts like #206 Crossing hitch.
The nipping structure is not able to rebound - it continues to contract.
The SPart also presses against the tail which further occludes the nipping structure.

Summary:
The 'anti' Bowlines where the collar and its legs are dressed in a more 'relaxed' state are totally jam proof.
Induce a rotation/twist in the collar to 'force' the tail upwards so that it is outside of the eye - and it now causes jamming.

I'll post some pictures when I get a chance.

Your imaged left- & right-most knots are the same,
IMO, though right-most is yet to take a geometry
pending load --i.e., the returning eye leg can fall
either before or behind the tail (and the left-most
image shows it doing the latter).  In the one case,
the tail then can become wedged/jammed against
the collar and ... jammed.  YMMV.

In some cases, it seems that the Eskimo BWL can
also capsize --another YMMV situation.

--dl*
====

[Andreas]

Dan, what means YMMV please?

About returning eye leg in front or behind.
Do I get you right?  You mean that Knot A is prone to jamming, Knot B less so?

[Dan_Lehman]

Dan, what means YMMV please?

About returning eye leg in front or behind.
Do I get you right?  You mean that Knot A is prone to jamming, Knot B less so?

"YMMV" = "Your Mileage May Vary" which is said as
a general note that one should expect different results
per situation (to some extent).

My remark was to Agent_Smith's trio of Eskimo BWL
images --that left & right were the same (BUT which point
to different dressings & setting of even this sameness into
knots that can have differing behavior.

Your Knot_A looks quite NON-jamming, and pretty nice.

As for an earlier assertion above --that
"All 'Bowlines' can easily be loosened by starting at the 'collar'"--,
doesn't ring true, for me.  If there is a loosenable collar, that's
certainly a compelling thing to work on!  But in one version
of a secure-when-slack BWL with opposed-bights collars,
it's less than easy to loosen a hard set such knot, and so leads
to the version where the tail can act as a lever to pull in
some SPart to start the loosening of the collar-bight legs.

As for the good ol' regular BWL, it always amuses to me to
read the "never jams" praise and then for the --in same book--
Water BWL comes its reason d'etre of avoiding a hard-to-untie
regular one!


--dl*
====