Author Topic: Second order retucked/enhanced harness midline loops and the equivalentEOL loops  (Read 6253 times)

tsik_lestat

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l wonder if they've been tied before.

Centuries ago, no doubt.

That might be the case, but until proven otherwise, a moniker like Double Alpineer's FBK loops, sounds eligible and rather euphonic so far ( aka Double Lineman's ABK loops :)).
« Last Edit: May 19, 2020, 03:53:04 PM by tsik_lestat »
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agent_smith

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Requesting load testing to determine jamming resistance in the following loading profiles:

[ ] Bi-axial loading from SPart-to-SPart
[ ] Eye loading (with one SPart anchored)

Alan Lee perhaps?

Or anyone else?

tsik_lestat

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                                                                         Mirror tying method

1. Form a Z loop, a bight, and an S loop knotting scheme, like the one illustrated in first image (in contsast with the tying method described at reply#1, where the initial configuration was S loop, bight, Z loop).

2. Place the S loop over the Z loop, (or the Z over the S loop), as shown in second image. Note, that you have to place the S loop, (or the Z loop), on Z loop's segment that is a direct continuation of the bight component, in contrast with the tying method presented at reply#1.

3. Pass the bight through this configuration, in the following order, ~ under, over, under, over ~.

The resulting mirror knot is shown in the next two images, in a loose dressing state, in front and back view.
« Last Edit: July 09, 2020, 04:09:03 PM by tsik_lestat »
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agent_smith

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Can I assume that the TIB bi-axially loadable eye knots presented at reply #31 and #32 are a claim of originality by tsik_lestat?

I need confirmation from the creator - because I really like these knots and want to include them in my upcoming paper on the #1053 Butterfly knot.

I also need to know if any load testing has been done to investigate jamming threshold in a variety of different loading profiles such as:
[ ] bi-axial through loading (from SPart-to-SPart so that the eye is isolated from load)
[ ] axial eye loading (in both directions aligned with each respective SPart)
[ ] transverse loading of the eye (some may prefer to use the term 'ring loading')

Has Alan Lee done any load testing?

tsik_lestat

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New evidence has emerged, which suprisingly prove that the EHL midline eyeknot, is a pre-existing knot structure, and apparently, a very old one too.

I have recently been informed by a brilliant collaborator and a valuable contributor, Knotsaver (Saverio), who has a thorough knowledge about knotting, that there had been a short reference of the knot presented in this thread, in the book "Encyclopedia of knots and fancy ropework" by Raul Graumont and John Hensel, first published in 1939, which appears in chapter II, titled "Simple knotting" on page 58, under the moniker of Cask knot.

I have attached photos of all the related content, thanks to Saverio, who was kind enough to enlighten me and deliver all the related material from his own book copy.

In this short reference, the authors provide an "in the end method" of tying the inline profile (??), and they also claim that there is no practical value, without providing any supporting arguments.

Having delved deeper into the mechanics and the topology of this particular knot structure, i'll have to add that i respectfully disagree with the viewpoint of the authors.

Also, many thanks to master Xarax, who has managed to ferret out another, a bit more recent, appearence of the knot, on a knotting board from the Mariner's museum and Park in Houston Texas, which dates from 1954.

It is number 64, the photo at the end of the page is great, you can zoom in to see all the details of this magnificent artwork.

Link : https://catalogs.marinersmuseum.org/object/CL2899

Anyone, who may know or may sniff out any additional info about the so called "Cask knot", is encouraged to appose it in this topic for further evaluation!

Afterall, we are still on the lookout for the original creator! :)
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siriuso

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tsik_lestat

In the same Plate 21, page 57. the configuration of the Jug Sling (Fig.1-A B) is the same as Cask Knot (Fig.8-A B). Also see my previous reply #12 and 18.

Happy Knotting
yChan

tsik_lestat

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Siriuso, thank you for your apt observation, you may consider it as my omission, even though i was aware for their illustration in the same plate, of the book cited previously.

Although the topological equivalence between the two knots (cask/jug sling) is obvious, but not pointed out by the authors (their omission :D), it seems to me that a couple of component rearrangements, render two geometrically and functionally separate configurations.

Note also the resemblance, between your depicted tying method, (taken from the book), and the one described in detail, at reply#32.

Yet still, we didn't get any closer to the mysterious Cask knot inventor, did we? :)
« Last Edit: February 14, 2021, 07:20:53 PM by tsik_lestat »
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agent_smith

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This reminds me that any claims of originality - in the fullness of time - can be hard to sustain and may result in disappointment.
Oh well.

What occurs all too often is independent rediscovery.
I'm surprised Dan Lehman hasn't chimed in with comments about the Hensel and Graumont publication... where the accuracy and reliability of the published content is often called into question.

I agree with tsik_lestat that the authors comments re "has no practical value" - is itself of no value!
I think some testing needs to be undertaken to determine jam resistance in various loading profiles.
The #1053 Butterfly knot jams when heavily eye loaded (when the eye is loaded axially in alignment with an SPart).
However, #1053 Butterfly is jam resistant when bi-axially through loaded (from SPart-to-SPart).

I have loaded this knot only to 2.0-3.0kN and found:
[ ] eye loaded (with the eye loaded in axial alignment with an SPart) = a lot of distortion but did not jam at these loads
[ ]  bi-axially through loaded from Spart-to-SPart = a lot of compression of the core but did not induce jamming.
(using human rated EN1891 or EN892 rope)

Obviously, these loads are trivial and more work needs to be done.