Author Topic: "New" post-eye-tiable eyeknot ?  (Read 7899 times)

X1

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"New" post-eye-tiable eyeknot ?
« on: April 06, 2013, 02:35:20 AM »
   A few days ago, alpineer published a new bowline based on a shape "8" nipping loop, the "Tresse bowline"(1). Needless to say, the warm reception of this very interesting, very tight and easy to tie knot by us, fellow knot tyers, had not contributed to global warming even a little bid... :)  Although I had tried this bowline some time ago, I had not studied it as much as I should, I had not appreciated its stability, so I did not examined it any further. Now I had tried it again, I see that it is worth its salt, indeed ! Perhaps I was seduced by the similar, but even more stable, and more symmetric, "Constrictor bowline" - or by the unexpected, almost miraculous stability of the "double, crossed coils adjustable loop" (2), which is essentially the same thing without a common bowline s collar, but where this shape "8" nipping structure is placed at a right angle to the axis of loading.  At this position, it is so tight and self-stabilizing a structure, that can hold the returning eye leg without any help from any collar ! So, I was searching for ways one could interweave a collar structure within the nub of this adjustable loop, in order to tie a fixed end-of-line loop - but a loop where this nipping structure would still be, and will remain. at a this beneficial right angle to the axis of loading. Why is this angle so important ? Because, when the nipping structure has this inclination, the returning eye leg which penetrates it, is forced to bent, so it takes an L-shaped form, which I call a "step". This "step" is the same thing that is utilized by the "Eskimo" (-) bowlines, a "horizontal" segment on which the eye leg uploads a great portion of the tensile forces that carries within it, before it reaches the collar.
   A first attempt was the "double, crossed collars bowline" (3)( the introduction, at the first post of this thread, attempts to explain the same things... ) - but in this knot the "double, crossed coils nipping loop" was forced, by the pull of the collar around the standing end, to twist, and align itself with the eye leg - so the initial purpose was not satisfied as much as it should. I plan to add a second, "Eskimo"-like double, crossed coils bowline, where the collar would encircle the eye leg of the standing part, so the nipping structure will remain perpendicular to the axis of loading.
   In this thread I present another idea : Manipulating the same structure, I had removed the eye leg from its path inside the "double, crossed coils nipping loop", and replaced it with the tail. The eye leg itself now reaches the tail from another path, going around the first curve of the eye leg of the standing part - and, doing this, it manages  to keep this leg in a firm contact with the rest of the knot s nub, in one coherent whole. With this very simple interchange, the nipping structure keeps its initial balance, it remains in the desirable right angle position, relatively to the axis of the loop, and the whole nub remains in a compact form, constricted by this "belt", the encircling continuation of the returning eye leg. I know that I can not explain what I am thinking, but that does not matter !  :) What really matters, is the stability and the tightness of this knot itself - a very simple and secure eyeknot, in a way "similar"(?) to the "Tresse" bowline. ( However, although it is a post-eye-tiable eyeknot, it is not a bowline, because it does not have a "proper" bowline collar ). As a very simple knot, it should have been tied many times, on purpose or by mistake - but I am not aware of any prior act  :),  so I dare to post it in this section. If it is a new knot, I would appreciate suggestions for a name - reminding some "similar" known knot, if possible.


1. http://igkt.net/sm/index.php?topic=4321.0
2. http://igkt.net/sm/index.php?topic=3233.msg19951#msg19951
    http://igkt.net/sm/index.php?topic=3233.msg19952#msg19952
    http://igkt.net/sm/index.php?topic=3233.msg19968#msg19968
    http://igkt.net/sm/index.php?topic=3233.msg20028#msg20028
3. http://igkt.net/sm/index.php?topic=3951.0

X1

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Re: "New" post-eye-tiable eyeknot ?
« Reply #1 on: April 06, 2013, 02:30:57 PM »
   In the previous post, I had decided to show the most "neutral" / "easy" dressing of this knot, so the interested reader would be able to "see" its structure at a glance. In the present post I show the form / variation which I prefer, because of the relative position of the two legs of the collar inside the "first" nipping loop : the returning eye leg is not parallel to tail, it pass "over" it, so it squeezes it underneath, as it should. This dressing is similar to the dressing of the most secure "Eskimo" (-)bowlines - and I wonder if this eyeknot should, in fact, be considered as just another, more complex form of an "Eskimo" bowline ( ? ? ).
   
« Last Edit: April 06, 2013, 02:33:01 PM by X1 »

X1

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Re: "New" post-eye-tiable eyeknot ?
« Reply #2 on: April 06, 2013, 07:27:29 PM »
   Pictures of a loaded knot (W=150 kg), tied on a 8 mm cord. The continuation of the returning eye leg remains perpendicular to the standing end, and the tail meets the rim of the standing part s first curve at the optimum right angle. 

X1

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Re: "New" post-eye-tiable eyeknot ?
« Reply #3 on: April 07, 2013, 09:46:19 AM »
   I could nt leave this knot in such an ugly form, could I ?  :) Going just one step further, to regain the balance between the "nipping structure" and the "collar structure" of the "king of knots", THE bowline, and finish this tangle, we arrive at the simple, beautiful, familiar form shown at the attached pictures. The nipping structure AND the collar structure follow identical, simple "8" paths, interweaved in an harmonious whole.
   I am not able to "defend" the virtues of this knot, which are evident to anybody, I believe. (*)
   Of course, this tangle was already been used as a bend during stone age  :)- I would argue that it is the most simple pattern two rope segments can follow in a symmetric "double" bend - the minimum piece of a textile.
  "The word 'textile' is from Latin, from textilis, meaning 'woven', and textilis is from textus, the past participle of texere, or 'to weave'".
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*   The [ knot tyer ] does not study [ knots ] because they are useful; he studies them because he delights in them, and he delights in them because they are beautiful. If [ knots ] were not beautiful, they would not be worth knowing, and if [ knots ] were not worth knowing, [ they ] would not be worth tying.
- Jules Henri Poincare (1854 - 1912)
« Last Edit: April 07, 2013, 09:48:01 AM by X1 »

X1

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Re: "New" post-eye-tiable eyeknot ?
« Reply #4 on: April 08, 2013, 01:33:22 PM »
   Pictures of the first / simpler eyeknot presented in this thread.
« Last Edit: April 10, 2013, 05:47:55 PM by X1 »

SS369

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Re: "New" post-eye-tiable eyeknot ?
« Reply #5 on: April 09, 2013, 01:44:20 PM »
I've tied this a few times now and have used a few different types of rope and cord materials/sizes. 

One observation: The tail looks susceptible to being dragged out under high load. Though I can't say why exactly. Maybe it's because as I stress it the tail moves to a sort of parallel position that all attempts have shown. The torsional stress of further tightening of the eye leg tail. ?)
Whether it will form a stationary lock at some point before breakage I can't say. But it is that movement inside that final nip that bothers me.

Maybe with compensating dressing/pre-loading of this area, the effect can be limited.

SS

X1

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Re: "New" post-eye-tiable eyeknot ?
« Reply #6 on: April 09, 2013, 07:10:56 PM »
   Thank you, SS369,

   The picture shows a tight knot where the tail has settled in a position "over" the returning eye leg, not "under" it, as it should have had. That may explain the dragging of the tail under high load you report. This 8 Loop is a very simple knot, and each and every element of it should be utilized, in order to work properly. The tail should be squeezed in between the standing part s first curve and the returning eye leg s first curve - otherwise it will not be locked properly. That was the initial idea : to have a horizontal, "Eskimo"- like tail, something like a "handle" or a "step", that would be "lifted" by the standing part s first curve, from below, and, at the same time, would be "trampled" by the returning eye leg s first curve, from above. Missing this favourable position, the tail at the knot you had tied was left without adequate support.

   
... as I stress it, the tail moves to a sort of parallel position
 
   
  Why is this happening ? Why the tail is twisted like this inside the knot s nub, and settles at this position parallel, or even "over" the returning eye leg, on top of it, instead of remaining "under" it, below its belly ? My first attempt to an explanation is that this twisting is due to the constant contact of the tail with the standing part, that spins / revolves the tail during the tightening phase, and inserts some considerable amount of torsion in it. So, as the knot is still shrinking but has not become 100% compact yet ( there is still some room in it, so the various segments can "move" relatively to each other ) this torsion manages to force the tail be displaced inside the nub, away from its initial "correct" position, to this final "wrong" position. I guess that one should pull the tail downwards, once or even twice during the lightening phase, to counter-balance this tendency.
    With the rather stiff, in-compressible, round ropes I use, I have not encountered this problem. ( See the B&W pictures of a loaded knot, tied on a 8mm cord, loaded with mine s and my son s weights  :) - the tail remains well underneath the returning eye leg ). However, we wish knots that can be tied in most materials, even on this pink slick compressible rope you show - so this displacement of the tail during the tightening of the knot should concern us, indeed. I can only say that the full, "finished" 8-8 knot ( where the returning eye leg and the tail, moving in this wave-like motion, penetrate both openings of the shape "8" nipping structure ) would not behave like this.
    Now, this 8-8 loop may be more robust, and very beautiful, but deviates substantially from the knot I had in mind when I tried to stabilize the "double, crossed coils nipping loop". The returning eye leg is tucked once more, and so it pulls the whole nub downwards - so the favourable horizontal position I was seeking for the L-shaped segment of the returning eye leg and the tail, the "handle" or "step", now runs the danger to disappear altogether ! The knot resembles more a "double Myrtle" loop, that a fixed "double crossed coils" loop. What can I say ? You win some, you lose some !  :) In such simple knots, even the slightest unbalance of forces can force the nub to rotate towards the one or the other direction / side. The mere presence of the bulk/volume of a rope segment in one place, that forces another segment going around it to be displaced a little bid, can cause a rotation, which might twist one segment, or even the whole nub ! Moreover, when we do not have a genuine collar ( a "proper" bowline collar or even a "Myrtle" collar), but a so-so "collar", as in the present knot, that turns around the standing part within the knot s nub ( and not "before" / over it, as it happens in the common (+)bowline, or "after" / under it, as it happens at the "Eskimo" (-)bowline ), we also do not have the required leverage that would stabilize an elongated nub in the required horizontal position
    Returning to the original 8 loop, I think we should test it on a variety of materials, before we kiss it good bye !  :) I would nt like a knot that would require a constant pull of the tail, or a careful dressing during the tightening phase, in order to lock correctly. Myself I have tied it on about two dozens of different ropes, without noticing such a severe twist of the tail inside the knot s nub - but I use only rather stiff, torsion-resistant, round, kermantle climbing ropes, so my tests are not very inclusive / conclusive.
    When somebody presents a "new" knot in the Forum, what does he wish for it ? I can not tell what other knot tyers are thinking, but every time I happen to do it, I do it with the same hope ; to persuade somebody to test it in detail, or find a reasonable argument, that would suffice to make me dismiss and forget it !  :) We already have too many knots, and I always hope we have already reached the end of the line . It would be nice to know that there is not any other good practical knot looming under our nose - so we would be forced to concentrate on the most important thing we still miss / avoid : KNOT TESTING !     

X1

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Re: "New" post-eye-tiable eyeknot ?
« Reply #7 on: April 11, 2013, 05:44:57 PM »
   Trying to discover the cause of the "rotation" of the tail reported by SS369, I used boating lines ( mooring lines, halyards and sheets ) which are less dense and less stiff, and softer / more "compressible" than the climbing ropes.
   I have seen that, as a general rule, the softer / more "compressible" is the rope, the smaller the angle between the tail and the returning eye leg becomes at the end of the tightening . At a softer rope, the tail rotates more, AND it s squeezed more by the standing part s second curve so it bents and points "downwards". However, I had not met even a single case where this angle becomes negative, so the tail, being dressed at an initial position "under" the returning leg s first curve, finally settles in a position "over" it . This slick soft cord used by SS369 should be a very strange animal, indeed !  :) Or the observed flip of the tail is caused by a combination of the very soft core AND the very slippery surface of this cord.
   See the attached pictures, for a sequence of pictures demonstrating this "general rule", from the stiffer / less "compressible to the softer / more "compressible" ropes. The 8 loop was dressed so the tail was at right angle with the standing part, and the returning leg was pulled before loading, so that any slack left inside the knot s nub was consumed. Then the loop was loaded, without any further manipulation of the tail. 

X1

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Re: "New" post-eye-tiable eyeknot ?
« Reply #8 on: April 11, 2013, 06:19:22 PM »
   And here is the same 8 loop tied on the softest rope I have : a 10mm double braid cotton rope. The tail is almost parallel to the eye leg, but it remains "under" it ( "behind" it, as shown at the picture).

SS369

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Re: "New" post-eye-tiable eyeknot ?
« Reply #9 on: April 11, 2013, 11:40:01 PM »
Using the "pink" cord (actually white quarter inch solid braid nylon) I have tied this a few times and I can make the knot settle into the position as X1 shows. The other form that I get is due to grasping the tail and the accompanying eye leg and pulling them simultaneously while I snug it all up.

It doesn't even require me to "super snug" it!

Some knots settle into the desired form with any sequence of tightening and some knot.

SS

X1

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Re: "New" post-eye-tiable eyeknot ?
« Reply #10 on: April 13, 2013, 10:00:53 PM »
   The "full" / "finished" version of this eyeknot, also shown at Reply#3 (1), now under moderate loading. The L=shaped segment of the returning eye leg is retained, and so is the favourable right angle at the contact point between the standing part s first curve and the last part of the tail ( the "last line of defence" against slippage ).

1. http://igkt.net/sm/index.php?topic=4340.msg27172#msg27172

Dan_Lehman

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Re: "New" post-eye-tiable eyeknot ?
« Reply #11 on: April 15, 2013, 04:34:42 PM »
   Trying to discover the cause of the "rotation" of the tail reported by SS369,
I used boating lines ( mooring lines, halyards and sheets ) which are less dense and less stiff,
and softer / more "compressible" than the climbing ropes.

I Just tried this knot in which my yachting rope (alas,
its exact composition I forget --bought it among a set
of several) draws up to match the images X1 shows.
With some few hundred pounds force on this 3/8"
braided (double or kernmantle, I forget) rope,
the SPart's curvature looks pretty gradual,
so one might surmise the knot's strong.

As for jamming, though, I suspect that it will
jam; maybe it will yet be amenable to being
pried loose with tools (& lubricant?!) --it's a
matter of breaking back the collar or not.


--dl*
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X1

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Re: "New" post-eye-tiable eyeknot ?
« Reply #12 on: April 16, 2013, 09:28:10 PM »
As for jamming, though, I suspect that it will jam;

  Nooope ! Your suspicion is unfounded - it does not jam - at least it does not jam when it is was tied on the same cord, and submitted to exactly the same torture ( and then some ! ), with the knot spoken by Oracle (1). In fact, it is very easy to untie - not harder than a common "Eskimo" (-)bowline eyeknot. How do I know it ? I had tied the "step"/ bight, tied on the other end of the rope, on which I used to jump ( to apply a bouncing, dynamic loading ) with the help of an "Eskimo" (-)bowline, and I have found that I was able to pull out and release the tightened bights and untie both knots with about the same force - without using any tools or lubricants, of course... 

1. http://igkt.net/sm/index.php?topic=4321.msg27251#msg27251

X1

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8 - 8 loop
« Reply #13 on: June 19, 2013, 11:46:02 PM »
   The nipping structure AND the collar structure follow identical, simple shape "8" [interweaved ] paths...
... it is the most simple pattern two rope segments can follow, in a symmetric "double" bend - the minimum piece of a textile.
  "The word 'textile' is from Latin, from textilis, meaning 'woven', and textilis is from textus, the past participle of texere, or 'to weave'".
   I have tied and tested all the possible patterns with which the nipping and the collar structures of the 8 - 8 loop can be interweaved - to see which particular patterns lead to loaded knots that retain the initial balanced, nice form of the unloaded nub more than the others.
   As the nipping structure is always the more heavily loaded one, I had expected that the particular under/over pattern of its segments would be more important than the particular pattern of the segments of the collar structure. Noope ! Whatever pattern  the segments of the shape "8" double nipping structure follow, the loaded knot does not loose its initial form. The lower part of the nub may twist around itself, i.e., make a 180 degree turn around the axis of the returning eye leg, but the initial nice form of the unloaded knot is always retained. On the contrary, the final form of the loop is sensitive to the particular pattern of the collar structure. I have seen that the segments of the returning eye leg should better follow this alternating over/under regular pattern, shown in the first pictures of this loop, otherwise the nub of the loaded knot may become quite distorted - and I do not like knots which, when loaded, take a form  that does not bear any resemblance to their initial unloaded form any more. A nice knot is supposed to remain nice even after under heavy loading !
   So, the lesson one has to remember is simple :
1.  Any "8"-shaped nipping loop is acceptable. The legs of the "8' can be crossed in an alternating over/under pattern, or not - it will not make much difference, regarding the form the loaded knot would settle in.
2. The segments of the returning eye leg, that form the collar structure, should follow an alternating over/under regular weaving pattern - otherwise the form of the nub of the loaded knot will run the danger to be severely distorted.
   Of course, ALL patterns lead to secure knots - because the amount of interweaving of the nipping and the collar structures is more than adequate, and any pattern, be it regular or knot, entangles the tail in a most secure way. However, it would be better to interweave the identical forms tied on the Standing Part and the returning eye leg in the way described in this post, to get a 8 - 8 loop that, when loaded, will retain its nice initial form.
 
   P.S. I should have mentioned that the possible combinations are 12 - I had not included all of them in the (second) picture, which was not meant to be all-inclusive . The nipping structure can be "regularly" ("over"/"under"), or "non-regularly" ("one side") interweaved ( two general classes, represented by the "white" and the "yellow" knots ). Then, the collar structure can be also "regularly" ("over "/"under") interweaved, or "non-regularly" "one side"- and this side be the "upper" one, or "non-regularly "one-side"- and this side be the "lower" one. So, 2 x ( 2 + 2 + 2) = 12. One may well ask : What happens with the duplication of the total number of combinations, according to if the returning eye leg, as the collar structure, enters into the nipping structure from the one or the other side of its "lower" opening ? I believe those cases are mirror-symmetric to cases already counted, because, due to the number of openings/nodes of the nipping structure (two), the tail will always exit from it from the opposite side through which it had entered into it.
« Last Edit: June 21, 2013, 07:31:25 AM by X1 »

Dan_Lehman

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Re: 8 - 8 loop
« Reply #14 on: June 21, 2013, 06:03:12 AM »
   I have tied and tested all the possible patterns
with which the nipping and the collar structures of the 8 - 8 loop can be interweaved
--to see which particular patterns lead to loaded knots that retain the initial balanced,
nice form of the unloaded nub more than the others.

Hmmmm, I don't think that you have (but I've not tried
to prove this mathematically) : I'm looking for one in
which the SPart-side eye-leg pulls on the rim of a
turn that crosses UNDER its closing part, opposite e.g.
to what is done in say the first-set white ones (where
SPart parts do not twist).

It would help to have the set of possibles drawn or else
shown in a regular setting to make the variations easy
to see (or I should say "easier" --it might not so "easy").
Some of the 2nd set of more colored ropes seem to have
seen some loading --which is a good thing to see, but
which makes recognizing the starting variation harder.

I've not yet put some of these to a stress test, but some
look good, and look able to take a finishing wrap & tuck
for added security.

(I might have long ago fiddled some end-2-end knot with
a like structure, both ends "twisting" in their interlocking.)


--dl*
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