International Guild of Knot Tyers Forum

General => Knotting Concepts & Explorations => Topic started by: X1 on July 22, 2012, 04:25:42 PM

Title: The Tweedledee bowline
Post by: X1 on July 22, 2012, 04:25:42 PM
   The Tweedledee bowline. "The fact that the two identical links, that are interlocked in the [ Tweedledee ] bend, are [ topologically equivalent to the unknot ], makes this bend also suitable for a bowline-like end-of-line loop." (1), (2). A variation of this bend, where the tails pass underneath the diagonal and are crossed / twisted around each other,  is shown at (3).
   This bowline is a rare example, where the nipping loops ( the "nipping structure" ) and the collars ( the "collar structure"), are geometrically identical. Of course, they are different knots, because the nipping structure is loaded through both its limbs ( 100% of the total load from the one, the standing end, and 50% of the total load from the other, the eye-leg-of-the-standing-part), while the collar structure is loaded only from one limb ( the eye-leg-of-the-bight, which bears 50% of the total load). However, this difference in loading is not sufficient to distort the general symmetric aspects of this loop, which is beneficial in its easy inspection.( Something similar happens at the double harness loop, as well as at the other loops mentioned at (4), where the two links are also topologically equivalent to the unknot.) The reader should notice the obvious differences with the ugly so-called "Zeppelin loop", where the two links are topologically equivalent with the overhand knot, ( so the first one - the one tied on the standing part and serves as the nipping structure - will most inconveniently remain tied even after second one - the one tied with the working end after the bight and serves as the collar structure - would have been pulled off ), AND where the loading destroys the beautiful symmetrical aspects of the base bend that is so badly misused here, the genuine Zeppelin bend.

1) http://igkt.net/sm/index.php?topic=1919.msg13267#msg13267
2) http://igkt.net/sm/index.php?topic=1919.msg16218#msg16218
3) http://igkt.net/sm/index.php?topic=3672.msg21244#msg21244
4) http://igkt.net/sm/index.php?topic=3984.0
Title: Re: The Tweedledee bowline
Post by: Dan_Lehman on July 22, 2012, 07:13:58 PM
   This bowline is a rare example, where the nipping loops ( the "nipping structure" ) and the collars ( the "collar structure"), are geometrically identical. Of course, they are different knots, because the nipping structure is loaded through both its limbs ( 100% of the total load from the one, the standing end, and 50% of the total load from the other, the eye-leg-of-the-standing-part), ...

Hmmm, one can wonder about the 50% and the (initial)
nipping loop --given that the eye leg's loading goes first
through the companion loop to reach the SPart-loaded
one.

Quote
... the ugly so-called "Zeppelin loop", where ... the loading destroys
the beautiful symmetrical aspects of the base bend that is so badly misused here,
the genuine Zeppelin bend.

But one should not limit one's view of what constitutes
a "zeppelin loop" (eyeknot)" --consider the rather nicely
retained Z. symmetry in "twinning* the eye-side's parts :
post #63 in (and rightmost knot presented)
http://igkt.net/sm/index.php?topic=1872.msg12866#msg12866 (http://igkt.net/sm/index.php?topic=1872.msg12866#msg12866)


 ;)
Title: Re: The Tweedledee bowline
Post by: X1 on July 22, 2012, 09:47:24 PM
one can wonder about the 50% and the (initial) nipping loop --given that the eye leg's loading goes first through the companion loop to reach the SPart-loaded one.

  I was talking about the "nipping structure", the two nipping loops of this "8" shaped knot, taken as a whole. I do not have the slightest idea about the distribution of the tensile forces within the two nipping loops...The same can be said for all the double bowlines - and it might even be the case that the second nipping loop does not add much to the total gripping power imposed upon the penetrating collar legs ! ( So, although we can be sure about the effectiveness of the two collars, we can not be sure about the effectiveness of the two nipping loops...). We have to measure  some things here... but, till then, we can do nothing else than keep talking !  :)
   
consider the rather nicely retained Z. symmetry in "twinning* the eye-side's parts

   What I mean is that the original Zeppelin knot, the Zeppelin bend, is such a well balanced knot, that the loading of the former tail, although it does not distort the total symmetry altogether, nevertheless it is a fly in the ointment... If the Zeppelin bend was not such a beautiful and unique rope mechanism, it would nt matter so much, I guess. After a proper dressing and initial tightening of the knots, both the Double harness loop ( this particular version ) and the Tweedledee bowline would also be distorted, albeit not in such a degree that would make them almost unrecognisable, at least to the novice knot tyer s eye.
Title: Re: The Tweedledee bowline
Post by: X1 on March 17, 2013, 09:57:07 PM
   I should mention a great advantage of this knot, that may remain unnoticed by somebody who is not prepared for this :   
   The ( straight limbs of the ) four ends meet the ( curved rims of the ) four nipping loops at right angles. When two segments of rope are squeezed upon each other at a right angle, they "bite" each other harder and deeper, so their relative motion is blocked very efficiently (1). The interested reader should tie the Tweedledee end-to-end knot (bend) and eyeknot (loop), to see by his own eyes how tight and secure they are, even when tied on very slippery material. Moreover, although the Tweedlelee knot is very compact, it does not seem to jam, even under heavy loading. I believe that the Teedledee bowline is one of the few bowline-like post-eye-tiable eyeknots that can safely replace the retraced fig.8 knot in most demanding, life threatening SAR applications.
     
1. http://igkt.net/sm/index.php?topic=2191.msg25286#msg25286
    http://igkt.net/sm/index.php?topic=2191.msg25358#msg25358
Title: Re: The Tweedledee bowline
Post by: agent_smith on March 19, 2013, 10:36:55 AM
Hi X1,

I do like this structure (as I've stated previously).

Can you confirm the differences between this structure and the one from this post: http://igkt.net/sm/index.php?topic=4278.0  ?  I'm checking all of your posts now to find the tying method. Got to fully understand this one...

Quote
I believe that the Teedledee bowline is one of the few bowline-like post-eye-tiable eyeknots that can safely replace the retraced fig.8 knot in most demanding, life threatening SAR applications

Hmmm, interesting.

This one is definitely making an appearance in the 'Analysis of Bowlines' paper. I've started to play with this already - but have not yet put it to the ultimate test. Need to run a few more vigorous tests before putting my own life-on-the-line. I still extensively use my own EBSB variant Bowline creation which is solid as a rock secure.

Mark

Title: Re: The Tweedledee bowline
Post by: X1 on March 19, 2013, 04:20:36 PM
   Thank you, Mark

   The best way to represent the "triple symmetric" Tweedledee knot, is offered by its first explorer, Roger E. Miles, at his book : Symmetric Bends - How to Join two Lengths of Cord - (1995), p. 85.  See the attached picture and open the KM file.
   A great advantage of so symmetric a knot is that it can be inspected at a glance - every mistake can be spotted instantly, like a fly in the ointment ! On the contrary, the less symmetric retraced/rewoven fig.8 knot - which can be tied in a large number of apparently similar but essentially different ways - can not be inspected so easily.
   We have only a few Double nipping loop / Double collar bowline-like post-eye-tiable eyeknots - which I call "Double-Double" eyeknots. I believe that the Tweedledee knot is the best of all, by far. At present, to me, it is the golden standard - because it is easy to tie and inspect, very compact, without dangerous openings that can be caught up somewhere, perfectly balanced between the nipping and the collar structure, does not seem to jam easily, most secure against slippage because of the right angles the segments are squeezed upon each other into the knot s nub... What else can we ask from a secure eyeknot ? I would like to see an experimental comparison of it against the Mirrored bowline, as well as against some other "Double-Double" eyeknots that have been tied recently : the Strangle collar Double bowline (1), the Constrictor x2 (2)(*), the Two collars Girth hitch "Eskimo" bowline (3), and even the most simple Mirrored ( or "anti-mirrored" ) bowline shown at (4).

1.  http://igkt.net/sm/index.php?topic=4300.msg26926#msg26926
2.  http://igkt.net/sm/index.php?topic=19.msg26753#msg26753
3.  http://igkt.net/sm/index.php?topic=4009.msg26872#msg26872
4.  http://igkt.net/sm/index.php?topic=4306.msg26951#msg26951

(*) P.S. 2013-4-21
     About the Constrictor x2 bowline, read
     http://igkt.net/sm/index.php?topic=19.msg27318#msg27318
Title: Re: The Tweedledee bowline
Post by: X1 on April 10, 2013, 10:04:22 PM
   The symmetric representation of the Tweedledee bowline shown by Roger E. Miles. and at the previous post, is not a tying diagram ! It may lead some knot tyers to believe that this is a very complex knot - it is not. In fact, it is a very simple one - just two shape "8" forms interweaved to each other in the most reasonable, symmetric and simple way. The four bights have to encircle the pairs of the parallel segments of each link, otherwise the knot will fall apart ! If the knot tyer remembers this simple requirement, he can not but tie the Tweedledee knot correctly.
   See the attached pictures for a sequence of moves one can follow, to tie it. Of course, every knot tyer would probably figure out another way, better suited to his dexterity and personal tying "style",  but the one shown can be used as a very simple guide one can begin with. 
   
Title: Re: The Tweedledee bowline
Post by: X1 on April 20, 2013, 04:09:52 PM
  Before one is going to load his Tweedledee bowline, it is better to pre-tighten it a little bid, by pulling simultaneously first the two ends of the "nipping structure s" link ( the standing end and the standing end s eye leg, and then the two ends of the "collar structure s" link ( the tail and the returning eye leg). This way he would have another opportunity to inspect the knot, and the knot by itself will become more well-formed, symmetric and compact - and it will remain so even after the final loading.
   Let us imagine that, for some reason, by mistake, by evil or by accident, the tail will be untucked, not once, but twice ! Will the knot be untied and the climber s life be endangered ? Nooope ! It will remain functional, at the form of the safe eyeknot shown in the last picture. Compared to the Teedledee bowline, the retraced fig. 8 knot s safety is one collar short !  :)

* I have replaced the pictures of the previous post with new ones, where the tying procedure of the Tweedledee bowline is shown in four easy steps.
Title: Re: The Tweedledee bowline
Post by: Luca on April 21, 2013, 12:57:18 AM
I do not know anything about the mentality of the climbers, all I know is that with a little patience, as you it seems to me are demonstrating, it is not really  hard to learn how to make this loop,also holding the knot "in the hand".I too (for what it's worth my opinion for that matter) I think it is a very safe loop, even with respect to the intermittent load with slacks, because the tail seems that is not practically affected by this occurrence.
Title: Re: The Tweedledee bowline
Post by: agent_smith on June 19, 2013, 02:29:29 AM
Hello X1,

Having played around a bit with the tweedledee bowline, I am sad to say that I believe it wont take any foothold with climbers or mountaineers any time soon. If we compare this structure to ABoK #1010 (modified with say a yosemite finish or with some other securing lock) - it is my personal view that the tweedledee bowline is more complex to tie (and hence more prone to tying errors and memory retention). Compared also to ABoK #1047 (figure 8 loop) - this structure has been the gold standard around the world for tying a rope to a harness (and still is).

I realise that in making such a comment - I open a pandoras box of interpretation of what is 'complex' and 'practicable'. Historically, ABoK #1047 has stood the test of time - and it is proven to work in climbing applications. With the advent of modern climbing styles where repeated falls occur on thinner ropes - there has been a swing in some quarters to the Bowline. As you know, one of the key properties of all bowlines is its inherent ability to resist jamming. However, the original #1010 form is not secure and stable - further steps need to be undertaken to render it secure & stable. Obviously, the knot is used in mission critical human life-support applications; so it has to work all-of-the-time.

However, I am interested in the "Twice untucked tweedledee bowline" - have you got any more (clearer/improved) images of this structure showing front and back?
This is a much simpler structure - and I am keen to assess its security and stability.

Note: I am still working on my next version of the 'Analysis of Bowlines' paper - but work and life keeps getting in the way of progress.

My intent is to include the more 'simplistic' structures with a reasonable possibility of practical application. I am not convinced that the tweedledee bowline fits this selection criteria (am not trying to be offensive or condemning - its just my opinion)... I do however think that your continuing efforts to tie and present knots is entirely creditable and will lead us in new directions of discovery and understanding.

Mark
Title: Re: The Tweedledee bowline
Post by: X1 on June 19, 2013, 05:53:51 AM
   If we compare this structure to ABoK #1010 (modified with say a yosemite finish or with some other securing lock) - it is my personal view that the tweedledee bowline is more complex to tie (and hence more prone to tying errors and memory retention). Compared also to ABoK #1047 ...(figure 8 loop)
   Of course it is ! There are many "lockable" bowlines that are more simple to tie than the Tweedledee. ( See the beautiful Lee s lockable bowline, for example, shown at the attached pictures ). However, the symmetry of the Tweedledee bowline is unique, as far as I know. I have tied, systematically and repeatedly, all the bends I know ( that are, most probably, all the bends that are known ) which are composed of links topologically equivalent to the unknot -the bends that generate post-eye-tiable, 'bowline-like" loops, that can be tied and untied in one stage. There is no safer alternative than the Tweedledee bowline.
   We have to recognize that "simplicity" of tying depends upon the experience of the knot tyer and the tying method he uses. The tying method that reproduces what the Teeedledee bowline really is, two interlinked shape "8" knots, as shown in :
 http://igkt.net/sm/index.php?topic=3989.msg27204#msg27204 (http://igkt.net/sm/index.php?topic=3989.msg27204#msg27204)
  makes tying it really easy to remember, easy to tie, easy to inspect and hard to tie wrongly ! However, I am not saying tthat it is easier to tie than the retraced fig.8 loop - which can be tied blindly, by just retracing the line of a fig. 8 knot. However, the fig.8 loop is not post-eye-tiable, and I was searching for a post-eye-tiable ( = "bowline-like") loop. Also, to my view, the Tweedledee bowline is easier to tie and inspect than most complex double nipping loop bowlines with a "yosemite" finish.
The Teedledee bowline...that I believe it wont take any foothold with climbers or mountaineers any time soon.
  I would bet on it !  :)  Climbers are very conservative in the use of heir tools ( as most professionals are ), especially in their knots, perhaps because they need to focus their attention to so many other things... However, that does not makes it less secure. Within the acceptable limits we are accustomed to respect, regarding practical knots, it is the most secure post-eye-tiable double nipping loop / double collar symmetric eyeknot I know. I underline the "symmetric", because it offers two advantages : It ensures an instant recognition of a mistake during tying ( because even the slightest difference from a correctly tied knot inevitably destroys the expected perfect symmetry, and it can be spotted at once during the inspection of the knot ), AND help a more even distribution of forces within such a lanyard knot ( the standing end and the tail are adjacent and parallel to each other, so the fact that only one of the two segments is loaded does not disturb the distribution of the forces running inside the knot s nub too much).
I am interested in the "Twice untucked tweedledee bowline" - have you got any more (clearer/improved) images of this structure showing front and back?
This is a much simpler structure - and I am keen to assess its security and stability..
   Come on, Mark ! As its name and origin tells, it is just the Teedledee bowline, when we pull he tail out of the knot s nub two times, for KnotGod s sake !  :)
   I wish to draw your attention to a large family of loops that are both PET and TIB. This is a combination of characteristics that makes hem very versatile, without being very complex. See the pet Loop, shown at the attached pictures, for example. A well known example ( that was not known to me, until recently !   :) ) , is the Double Dragon. All those loops are eyeknots based on a crossing knot s nipping structure, which is a very stable configuration : it can easily be incorporated into a knot in a way that will ensure it will not open up, and degenerate into an helix - the common danger of the "common" bowlines ( i.e., the non-"Eskimo"-like ones ). 
Title: The Tweedledee bend and loop : What is it, and how to tie ( Stage 1 )
Post by: X1 on June 19, 2013, 12:15:27 PM
   A drama in four acts... :)
   
   Stage 1. 
 
   Form an 8-shaped double nipping loop ( on the one end of the end-to-end knot (bend), or on the standing part of the eyeknot (loop) )
   ( just like a Constrictor hitch, where the poll has been removed  )   
    It is a mid-line form, tied-in-the-bight (TIB), topologically equivalent to the unknot ( just as the Constrictor is ).   
   The purpose of the whole tying sequence is to weave an identical second 8-shaped double nipping loop, formed on the second line, within and around this first  one. The Twedledee bend / loop is one perfectly symmetric, in form, connection between two 8-shaped double nipping loops.
   ( In the case of the eyeknot, where the second such loop is tied on the returning eye leg, we can also call it an 8-shaped double collar - but it is exactly of the same shape as the shape of the 8-shaped double nipping loop formed on the Standing Part.) 
   
      Therefore, all the knot tyer has two do during the first stage, is to :
1.   Remember that the first 8 - shaped double nipping loop can, and should be, tied-in-the-bight - he has not, and he should not, use the end of the line on which he is going o form it.
2.   Pay attention to the side the two ends and the "diagonal element" will be ( the "diagonal element" would have been the oblique riding turn, in the case of the Constrictor ): At the end of the Stage 1, the two ends will both be under / beneath the diagonal element  -  the diagonal element will be over / above both the two ends.
    I suggest that the knot tyer better forms the 8-shaped double nipping loop in the middle of a line a number of times, so he will be able to reproduce the form shown in the picture with ease and speed, before he proceeds any further.
Title: The Tweedledee bend and loop : What is it, and how to tie ( Stage 2 )
Post by: X1 on June 20, 2013, 10:32:24 AM
   Stage 2.
   Introduction :
 
   In this stage, the second line of the unformed, yet, second "8"-shaped double nipping loop starts to get interweaved with the 8-shaped double nipping loop that has already been formed on the first line - and which will not change in any way till the very end of the tying. Doing this, the second line will achieve four things :
  1.   It will be entangled with the first line.
  2.   It will form the second "8"-shaped nipping loop, identical to the first one.
  3.   It will wrap the ends and the bights of the first "8"-shaped nipping loop, so that it will not be able to open up when the knot will be loaded.
  4.   By wrapping the ends and bights of the first "8"-shaped form, its own ends and the bights will also be wrapped together - whatever happens to the first "8"-shaped double nipping loop happens to the second, too, because of the perfect symmetry of the knot. If the ends and bights of the one link of the bend, in the case of the Tweedledee bend, or the nipping structure of the loop, in the case of the Tweedledee loop, are bound together by the encircling path of the second line, the same will happen, automatically, to the ends and the bights of the second link of the bend, or the collar structure of the loop, that will be formed by this second line.

   After this brief introduction, which clarifies the purpose of the subsequent moves by which the second "8" shaped double nipping loop will be formed and entabgled within and around the first, here is the description of the most simple Second stage :
   
   Draw the end of the second line ( the end of the second rope, in the case of the Tweedledee bend, or the end of the returning eye leg, in the case of the Tweedledee loop ) through both nipping loops of the already formed first 8-shaped double nipping loop.
   
   There are two symmetric ways one can do this, the "under/over/under" way, and the "over/under/over way", so the second line can penetrate the two bights of the already formed first shape "8" form going "under" the rims of the two bights and "over" the diagonal element, or "over" the rims of the two bights and "under" the diagonal element, respectably.
   Follow the way shown in the picture of the Stage 2.
 
   So, let the line of the second "8"-shaped link of the bend or collar structure of the loop go "under" the first bight, "over" the diagonal element, and finally "under" the second bight. Why ? It is important to understand why one does this and not the opposite, so he will not have to remember the correct way... The second line which is going to penetrate the first "8"-shaped form, is one of the two parallel and adjacent lines of the second "8" shaped form, so it has to remain at the outer core of the knot, just as the two parallel and adjacent lines of the first "8" shaped form do. Anything we are going to do from now on, it has to be done in such a way that will leave the two straight parallel and adjacent lines of both "8" shaped forms at the outer core of the knot, "over" the two diagonal elements. On the contrary, the diagonal elements, both of them, have to remain "under" the pairs of the adjacent parallel lines.
   If one looks at the finished knot, he will not be able to distinguish the two diagonal elements, that will remain at the inner core, buried inside the knot s nub. So, at this Stage, as well as at the subsequent third and fourth Stages, anything one does should be done in a such way that will not lead to a knot where one or both the diagonal elements of the two "8"-shaped forms would be visible.
   
   Therefore, all the knot tyer has to do at this stage, is to draw the second line through both bights of the first "8"-shaped form - that is, penetrate the first "8"-shaped form by this second line -, going "over" the diagonal element. The diagonal elements should always rermain "under" all other lines, buried into the knot s nub.
Title: Re: The Tweedledee bowline
Post by: Ruby on June 20, 2013, 11:59:58 AM
Perfect. It's easy, since it's just constrictor form.
When used as a bend, I'd tie it by first tie a what knot 1 406, and then add a tuck using each tail.
Title: Re: The Tweedledee bowline
Post by: X1 on June 20, 2013, 02:04:32 PM
Perfect.

   Indeed.

it's just constrictor form.
  NO, it not ! That is what I tried to tell in my previous post...It "looks" like a Constrictor, but it is not, since each pair of parallel adjacent lines of each link penetrates the two bights of the other link in the exact opposite way it would had penetrated them, were it in the place of a Constrictor hitch s pole.
   We may say that those two "8"-shaped interweaved double nipping structures are not two Constrictors embracing each other, but rather two Constrictors back-to-back to each other, in the field of honour, before a pistol duel !  :)
" For a pistol duel, the parties would be placed back to back with loaded weapons in hand and walk a set number of paces, turn to face the opponent, and shoot."

See the attached pictures, for a proper Constrictor bend.
Title: Re: The Tweedledee bowline
Post by: X1 on June 20, 2013, 02:40:07 PM
Quote from: Ruby link=topic=3989.msg2W113#msg28113 date=1371725998
When used as a bend, I'd tie it by first tie a whatknot 1406, and then add a tuck using each tail.

   Roger E. Miles, who discovered this bend, suggests such a tying method, which leads first to the Dee bend ( M. A 10 ), and then, by "inserting free ends symmetrically", to the Tweedledee bend ( M. A  24 ). Personally, I prefer the more intuitive method described in this thread, because it generates, step by step, what this bend really is : those two "8"shaped forms, symmetrically entangled to each other. One does not have to remember anything -  he should only do the only thing he can do to tie it, so it is perfectly symmetric, and the diagonal elements remain iside the knot s nub.
   See the attached pictures for a sequence of moves that leads to the Dee bend.
 
Title: Re: The Tweedledee bowline
Post by: X1 on June 20, 2013, 02:48:40 PM
   Pictures of the Tweedledee bend - for people that do not follow the links I offer... :)
Title: The Tweedledee bend and loop : What is it, and how to tie ( Stage 3 )
Post by: X1 on June 21, 2013, 09:26:46 PM
   Stage 3.
 
   Now the knot tyer has made the second line penetrate the first "8"-shaped nipping loop ( i.e, go "under" its "first" bight, "over" its diagonal element, and "under" its second bight ), he has to make it turn left or right, so it will form the first bight of the second "8"-shaped nipping loop, that will be interweaved with the already formed first one. 
   Should he remember if the line should make a left or a right turn ?   
   Nooo ! Because he has just to make the proper turn which will ensure the integrity of the first "8"-shaped nipping loop. That would be obviously a "left" turn, as shown in the picture.   
   
   Remember the "Introduction", before Stage 2 ( Reply #12 ).

..." the second line will...
... wrap the ends and the bights of the first "8"-shaped nipping loop, so that it will not be able to open up when the knot will be loaded."
 
    There is only one turn that can achieve this, the "left" turn, as shown in the picture. No need to remember anything, just understand, and follow the only reasonable / possible way that can ensure the integrity of the first "8"-shaped nipping loop. 
    Now that the line has made a "left" turn, and has wrapped the one end ( of the first "8"-shaped nipping loop ) with the one leg of its one bight, it has to complete the turn, "close" the first new bight, and cross the diagonal element, in order to form the second new bight.       
    Here, too, the previously stated simple rules will deternine the only possible way this can be done : Because the knot tyer has not, in this point, too, to remember the exact path of the second line. It suffices to draw the line in the only way the diagonal element of the first, already formed "8"-shaped nipping structure will remain in the inner core of the knot  -  every other line has to go "over" it. Therefore, the line should cross the diagonal element going "over" it. Also, it suffices to draw the line in the only way the diagonal element of the second, now forming "8" shaped collar structure will also remain in the inner core of the knot. Therefore, the line should cross itself going "under" it.   
   As said again in the instructions describing the previous Stage :
   
    Anything we are going to do from now on, it has to be done in such a way that will leave the two straight parallel and adjacent lines of both "8" shaped forms at the outer core of the knot, "over" the two diagonal elements. On the contrary, the diagonal elements, both of them, have to remain "under" the pairs of the adjacent parallel lines. 
    If one looks at the finished knot, he will not be able to distinguish the two diagonal elements, that will remain at the inner core, buried inside the knot s nub.   So... anything one does should be done in a such way that will not lead to a knot where one or both the diagonal elements of the two "8"-shaped forms would be visible.
   
   Therefore, all the knot tyer has to do, is to draw the line so that :

1.   It will pass "over" the diagonal element of the first "8" shaped (nipping) structure - so that this diagonal element would always remain in the inner core of the knot s nub.
2.   It will wrap the leg of the bight and the end of the first "8"-shaped nipping loop together.
3.   It will pass "under" the diagonal element of the second "8" shaped (collar) structure - so that both diagonal elements, of both "8" shaped structures, the one of the nipping structure and the other of the collar structure, would always remain in the inner core of the knot s nub.
 
Title: Re: The Tweedledee bowline
Post by: X1 on June 23, 2013, 06:16:31 PM
  Stage 4.

  At this stage, the knot tyer can be helped by the symmetry of the already tied part of the second "8"-shaped nipping loop. Or, he can follow the same reasoning that had helped him proceed till now : He should drive the working end to make a right turn, in order to accomplish two things :

  1. to encircle, and wrap together the first end and the second bight of the  "8"-shaped nipping loop together, and to drive the working end so it becomes parallel and adjacent to this first end.
  2. to encircle and wrap the first end of the  "8" shaped nipping loop it belongs, too, in order to be entangled with it, too - as it happens with the bights all over the knot s nub : they encircle and wrap together the two pairs of any parallel and adjacent ends meet in their way !

   Important note : This is the only time  the working end has to encircle three segments at one stroke : the two segments of the first "8"-shaped nipping loop, and the first end of the second "8"-shaped nipping loop that had been formed during the last 3 Stages. I have to mention this, because it is a point where the inexperienced to tie the Teedledee bend or loop knot tyer runs the danger to make a mistake... I, too, had made this mistake many times, when I was tying this knot at the beginning, because I was fooled by what I had to do right after this move : to drive the working end of this second double nipping loop in a position it will become parallel and adjacent to the first end, so then, just by retracing this first end, to drive the working end out of the knot s nub. Yes, one should do this, but he should not be too quick : he first has to complete the formation of the second bight of the second nipping loop, that encircles its own end, and, to do this, he has to encircle all the three segments he will meet in his way.
    I believe I should not repeat that, right after this move, this working end has to go "over" the diagonal element, as all the parallel and adjacent segments of this knot do...Then, it should go "under" the bight of the first "8"-shaped nipping loop, and get the hell out of the knot s nub !  :)  Attention : I said :  "under" the bight of the first "8"-shaped nipping loop", NOT "under everything"  !  :)  If, at this point, the working end goes under everything, i.e. under both bights, of both nipping loops, the knot would be tied wrongly. It will not make any difference regarding the overall security of the knot, but it will deform its nice, symmetric shape, which helps us inspect if we made any mistakes during tying, at a glance.

   I know that the my ability to describe a sequence of moves in a language I have only an inadequate, very rudimental knowledge and experience of is very limited, and this fact, added to the fundamental difficulty of any language to describe the curvilinear, convoluted paths of the segments of knots in 3D space, does not help at all !  :)  To the brave interested reader that has read all those four verbal descriptions of the four Stages / pictures, I say one thing : Tying this ultra-symmetric knot ( Roger E. Miles calls it "triple symmetric" , for reasons I can not explain here ) is MUCH MUCH easier than it sounds ! The greater help is offered by the symmetry itself : whenever we make a however small mistake, make a wrong turn or tuck, the end result would be awfully distorted, so we will notice that something went wrong at once, during the inspection of the knot. The mistakes that can not distort the final image very much, can not influence the security of this knot at all ! I had deliberately tied all the possible knots, doing all the possible mistakes one can do, if he follows the sequence of moves I describe. One end up either with an ugly tugly, which bears no relation with this beautiful knot whatsoever, or with a slightly different knot, that it is as secure as the one he should had tied. If one or both parallel and adjacent segments do not occupy the correct positions, and the knot looks like the more simple form of the Tweedledee bend or loop shown at the attached pictures, the overall security is not jeopardised : I prefer the more compact, tighter form I describe in this thread, but the simpler forms are also OK, and also extremely secure !
   
   My message is simple and clear : If one understands what this knot really is, its structure, the way it achieves the interlocking of the two "8" shaped double nipping loops ( leaving the diagonal elements deep inside the knot s nub ), he will never have any problems with its tying. He should not remember things, he should only follow the only reasonable and possible path that can lead to tie it.
   
Title: Re: The Tweedledee bowline
Post by: Ruby on July 06, 2013, 07:49:17 AM
wow , you write so many many sentences ...

someone says that a pic is more than one thousand words ...
maybe you've wrote more than thousand words ... ;D


anyway, perfect knot.  for bend. for loop.  and , for webbing, too.
Title: Re: The Tweedledee bowline
Post by: X1 on July 06, 2013, 09:40:31 AM
   maybe you've wrote more than a thousand words ... ;D
  2440, to be precise !  :)
  The four ( 4 ) pictures shown at Reply # 6, (1), were more than enough, I know... I will be so glad if somebody will manage to say the same things in just a few words ! The interested reader is kindly requested to try his/her hand - and then I will be free to proceed and draw what I am really interested in : a 3D PDF file image of this knot, which one can rotate, translate, zoom and expand  to whatever angle, distance, scale and volume he/she wishes...
 
 1.  http://igkt.net/sm/index.php?topic=3989.msg27204#msg27204 (http://igkt.net/sm/index.php?topic=3989.msg27204#msg27204)
Title: The Tweedledee bowline
Post by: X1 on July 20, 2013, 12:27:44 AM
   The TweedleDee bend, shown by Roger E. Miles ( and the eye-knot which corresponds to it ) is, in fact, a very simple knot - just two "8" forms, interwoven to each other in the most reasonable, symmetric and simple way. The four bights have to encircle the pairs of the parallel segments of each link.   
   See the attached pictures, for a sequence of moves to tie it. The pictures shown, and the brief verbal instructions below, can be used as a very simple guide : 
   
   First picture / stage:   
   Form an 8-shaped, diagonally opposed double nipping loop on the Standing Part of the eye-knot, where the straight segments of the Standing Part and the working end lay parallel against each other.   
   The purpose of the whole tying sequence is to weave an identical second 8-shaped double nipping loop, formed on the second line, within and around this first one. It should be of exactly the same shape as the shape of the 8-shaped double nipping loop formed on the Standing Part.   
   
   Second picture / stage :   
   Pass the working end through the "8", as shown in the first picture.   
 
   Third picture / stage :   
   Crossing under the working part, directly over the parallel segments of the first "8".   
 
    Fourth picture / stage :   
   At this point, take the working end around the second "8" shape and around the working part, to come through the second nipping loop - running against itself, as it exits through the first nipping loop. 
 ( Notice that, between stage 2 and stage 3, the working end encircles two segments, of the first "8", while between stage 3 and stage 4 it encircles three segments : two segments of the first "8", AND the working part of the second "8". So here, the knot tyer, repeating what he did between stage 2 and stage 3, he may make the mistake to pass the working end around the two segments of the first "8" only, but to forget to also pass it around the working part of the second "8". )
Title: Re: The Tweedledee bowline
Post by: alpineer on July 20, 2013, 10:38:25 PM
The Tweedledee is an inside-out transformation of the most beautiful, compact and symmetrical knot, the 2-strand 2-fold Matthew Walker Knot. I stumbled upon the Tweedledee (c.1997-'99) while searching for good alternative harness tie-in knots. I'm not sure if I'd seen it (the Tweedledee) in Roger E. Miles book by then or not.

I too use the tying method you've shown. True, I don't find it difficult to remember, but being somewhat awkward and time consuming to tie I find it lacks good hand and brain ergonomics. Sure, it's easy to tie while relaxing in your living room, but IMO it won't so easily pass muster when one may be suffering mental and physical stress, or worse yet shock, and when one's focus can be distracted by several things simultaneously. These scenarios can and do happen in the natural environment. Harsh criticism? Yes. But the world can be a harsh place with potentially harsh consequences. It's the nature of the endeavor to put such things under a harsh light before a catastrophic event happens.     

The Tweedledee is not TIB and for that reason it's a bit of a one trick pony at best.

I don't classify this knot as a Bowline. Is every knot that's PET knot now a Bowline?
Title: Re: The Tweedledee bowline
Post by: X1 on July 20, 2013, 11:31:46 PM
True, I don't find it difficult to remember, but being somewhat awkward and time consuming to tie

   It is amazing how much of this time is reduced after one tie it, say, 100 times. One has only to spend a few hours tying it again and again, and then it comes very easy and fast, indeed. I believe that a few hours of training, even a few days of training, are not such a long time for a serious climber or rescue worker.

   IMO it won't so easily pass muster when one may be suffering mental and physical stress, or worse yet shock, and when one's focus can be distracted by several things simultaneously. These scenarios can and do happen in the natural environment.
   the world can be a harsh place with potentially harsh consequences. It's the nature of the endeavour to put such things under a harsh light before a catastrophic event happens.   
   
   All very true. I can not say anything about tying it under such circumstances - on top of raining, snowing, freezing, waves, moving objects, dark, fatigue, danger, people around suffering, you name it...The Fig.8 knot can be tied almost blindly, by a fraction of one s brain cells devoted on this action.

The Tweedledee is not TIB and for that reason it's a bit of a one trick pony at best.

   I would love to have a PET + TIB secure eyeknot, with a double nipping turn and a double bight component / collar.
   However, I wish a few mooore things  :) : I am convinced that it is better, re. strength, if the nipping turns encircle three rope diameters - and if the eyeknot can remain functional, even in the absence/cut, by accident or by mistake, of one or even two collars.
   The Luca s bowline , with a double collar in the shape of a fig.8 knot, is TIB, but its nipping turn encircles two only rope diameters, and its grip on the fig.8 collar is not optimum.
  The bowline with the Lehman s lock is TIB, too, but it has only one collar. The pet loop I had presented, and its 3 siblings, seem too fragile to be used as secure bowlines. You can possibly test the double collar TIB bowline based on the Jug sling, or Mike s fancy bend, called "coming and going" bowline, shown at :

http://igkt.net/sm/index.php?topic=4336 (http://igkt.net/sm/index.php?topic=4336)
http://www.youtube.com/watch?v=Zqh3-uC94aA (http://www.youtube.com/watch?v=Zqh3-uC94aA)

 
   I don't classify this knot as a Bowline. Is every knot that's PET knot now a Bowline?
 
    To my view, if it is PET AND it has collar(s), it is a bowline...The Tweedledee eyeknot is PET, AND it has collars, plenty of them   :)  - four, two for each eye leg ! The epitome of a double/double bowline !  :)  However, let us not play this name game too much...
Title: Re: The Tweedledee bowline
Post by: X1 on July 21, 2013, 09:58:36 AM
The Tweedledee is not TIB and for that reason it's a bit of a one trick pony at best.
Reading :
the Tresse feature makes a TIB Bowline which renders the two eyes virtually independent of each other -
 ...an alternative to the Double Bowline on a Bight or the Fusion Knot aka Karash Double Loop.
   I thought that you might have meant the same thing in your comment about the Tweedledee bowline - that it can not be used as a basis for a Double TIB bowline...( Double, here, means : two eyes )
   If that is so, I have to say that the "inability" (or "ability") to do this can not turn such a fine horse into a trick pony... :)  ( a "tricky pony, at best" (sic) ! )
    Nor it turns the Tresse bowline frog into a prince !
    I am kidding, of course... :)  The Tresse bowline is a fine bowline, very stable and secure - my problem with it was/is the same I have with all double nipping turn but single bight component (collar) bowlines : The one element of those bowlines is sophisticated, while the other remains naive... For a secure bowline, able to withstand the material and psychological conditions you describe, I believe we need a double nipping turn + double bight component bowline - like the one shown at :
http://igkt.net/sm/index.php?topic=4321.msg27020#msg27020 (http://igkt.net/sm/index.php?topic=4321.msg27020#msg27020)
   
   We have dozens of most secure double TIB bowlines...many more than we need ! It is the most easy knot to create - in fact, it seems that every time one sits for some time and try, he can create another one, that probably would be new ! Ashley explicitly says the same thing, and the number of double TIB bowlines he presents in the ABoK chapter on double loops (12) is the largest of all other types of knots, by far ! If you wish to travel to the Double TIB boelinedom, I have to inform you that you are already there !  :)  Myself I will not spend another minute of my remaining life in this type of knots. and I do not care, and I do not even examine if a particular bowline can be turned into a double TIB bowline, or not !
   On the other hand, a TIB bowline is a most welcomed thing ! My answer was addressing the question of a TIB bowline, not of a double/twin eyed TIB bowline ! If you find a new TIB bowline, I will be here waiting for you, with open arms !  :)
 
   
Title: Re: The Tweedledee bowline
Post by: X1 on July 21, 2013, 11:12:31 AM
for the 4 steps, I think the first step is most important.
I think that the first step is known to most knot tyers, because that is the way they tie the Constructor.
To me, the tricky part, where one can make a mistake, is, most probably, the last one : Although it is sooo boring, and it consumes a lot of the bits and bytes of this Forum, perhaps without reason, and is such a wordy mess, I will repeat it :
Important note : This is the only time  the working end has to encircle three segments at one stroke : the two segments of the first "8"-shaped nipping loop, and the first end of the second "8"-shaped nipping loop that had been formed during the last 3 Stages. I have to mention this, because it is a point where the inexperienced to tie the Teedledee bend or loop knot tyer runs the danger to make a mistake... I, too, had made this mistake many times, when I was tying this knot at the beginning, because I was fooled by what I had to do right after this move : to drive the working end of this second double nipping loop in a position it will become parallel and adjacent to the first end, so then, just by retracing this first end, to drive the working end out of the knot s nub. Yes, one should do this, but he should not be too quick : he first has to complete the formation of the second bight of the second nipping loop, that encircles its own end, and, to do this, he has to encircle all the three segments he will meet in his way.
 
AND, I will repeat it again ! :
   Notice that, between stage 2 and stage 3, the working end encircles two segments, of the first "8", while between stage 3 and stage 4 it encircles three segments : two segments of the first "8", AND the working part of the second "8". So here, the knot tyer, repeating what he did between stage 2 and stage 3, he may make the mistake to pass the working end around the two segments of the first "8" only, but to forget to also pass it around the working part of the second "8".

 
Title: Re: The Tweedledee bowline
Post by: X1 on July 21, 2013, 12:22:12 PM
    Every knot tyer ties the same knots with a different methods.
    See how I arrive at stage 1 :

A. Form an S.
B. Push the two legs of this S towards each other / towards the centre.
C. Now they are parallel and adjacent to each other. ( In the B&W picture, I leave a little room between them, so one clearly sees them as a pair, and not as one thick rope !  :) )
4. Flip the whole thing / place it upside down.
   Of course, one can do the same thing, pushing the legs "under" the diagonal element, not "over" as shown here, so he will no have to flip the knot at the end. However, personally I prefer the method shown, because it offers me a better control / handling of the whole knot - and, to arrive at the picture shown as stage 1, it starts with a normal S, not with its mirror image !  :)
   
   Piece of cake - but there might well be another, simpler yet method I am not aware of.
Title: Re: The Tweedledee bowline
Post by: X1 on July 21, 2013, 02:26:44 PM
when you get to the 3rd step, acturally the loose knot is a mess,
since in fact it's a rope of a single color, not two distinct color like showed in picture.
   When possible, I always prefer to use a tying method where the parts of the knot, as they are formed, are placed in the same - or nearly the same - position inside the knot s nub, in relation to the position they will occupy in the final, dressed and tightened knot.
   Believe it or not, I keep the "8" shape of the first link as it is shown in the pictures, and I do not see any problem in weaving the second "8" within and around it - because those two symmetric, "closed", nice forms, although they have the same colour !  :) , in my eyes they always remain two completely separated, individual objects. I do not see any mess, because my eyes, helped by the symmetry, are perceiving the ordered "superposition" of those two individual links, and not their tangled sum.
Title: Re: The Tweedledee bowline
Post by: X1 on July 21, 2013, 02:47:40 PM
well, seeing these 4 steps to get the stage 1 ,
I can't help but thinking that it's so complicated ... :D
It may seem so, but, conceptually, it is not !
Read my previous reply. The image of the whole thing remains as close to the image of the final dressed and tightened knot as possible
Title: Re: The Tweedledee bowline
Post by: X1 on July 21, 2013, 02:53:03 PM
the working end should be threaded through this double loop twice, easily , even without looking at the rope.
Perhaps you can make a video of your method ? Or show it in a series of MANY pictures, step by step, because I believe you have jumped over some steps in your verbal description.
Title: Re: The Tweedledee bowline
Post by: X1 on July 21, 2013, 04:10:16 PM
  Good !  :)  Can you show the same sequence of pictures / steps, with ropes, not drawn lines ? If you find it difficult to stabilize the structure, try to use pins, and start from a double loop of a smaller inner diameter, so it remains stable by the stiffness of the material. Beware, because pins are such pointy objects !  Try to take the pictures from the dame angle, perhaps using a tripod for your camera ? A one-colour rope would be better. I like the shadows on the white surface, they give a nice sense of depth.
   ( They are the same thing topologically, of course, but, geometrically, do they look like the same ?  :)  The symmetry of the final knot is lost in your double loop, only to be found much later, at the very end, after the tightening, while on my shape "8" double loop it is retained through out the tying procedure. )
Title: Re: The Tweedledee bowline
Post by: alpineer on July 21, 2013, 07:05:56 PM
The Tweedledee is an inside-out transformation of the most beautiful, compact and symmetrical knot, the 2-strand 2-fold Matthew Walker Knot.
。。。

this is interesting  :D

how do you find this out?

how to perform this transformation ? I tried, but failed. :)

Hi Ruby,

To see this transformation it's best to use two short (1m) lengths of cordage - giving easy access to all four ends - which is how I've conducted my knot explorations since the late '90s. With access to the ends it's easy to re-route all four ends under the central crossing parts of the Tweedledee to get the MWK. As the eyeknot version will allow you to do this only as a tying procedure I must apologize to you for (unintentionally) misleading.

I found this out working from the MWK. Lamenting the MWK's unsuitability as a climber's tie-on - as I love it's wonderful symmetry - lead me to re-routing the ends and discover the Tweedledee form. I suspect this is how Roger E. Miles originally came upon the knot.
One should now see intermediate and hybrid knot forms between these two extremes.     
     
Title: Re: The Tweedledee bowline
Post by: X1 on July 21, 2013, 08:45:14 PM
Lamenting the MWK's unsuitability as a climber's tie-on - as I love it's wonderful symmetry - lead me to re-routing the ends and discover the Tweedledee form. I suspect this is how Roger E. Miles originally came upon the knot.

   On the contrary, I am sure he did not come upon this knot that way !  :)
   He was just trying to tie all the possible simple symmetric bends there exist - and I know it, because when I re-discovered it, I was trying the same thing, being unaware of his book... and because he has told me so !  :) 
   I remember very well how I came upon it, 3 1/2  years ago - which was by systematically applying an anything but "random" method, as I was accused too easily by some "founding fathers" here... who were unable to "see" the method under the madness  :) . I simply collected all the symmetric hitching tangles, and tried to connect them one-to-one in every possible way. I started from the shape "8" overhand knot, the fig.8 knot, the Clove hitch, the double overhand knot / Strangle, the Constrictor and the Pretzel ( which is less symmetric than the others) - and I had connected each one of them to each one else, in every symmetric way I was able to figure out. That is, plain dumb, systematic work, that does not need any imagination to be accomplished ! Of course, the most interesting cases were the symmetric ones, where the two links were identical. The particular knot, the Tweedledee ( I had called it the "88" bend at that time, for obvious reasons ), and the somewhat similar topologically but completely different geometrically Oyster bend, were rather easy to tie. I remember that the problem was how to keep each link in one piece, by encircling/connecting the curved segments of the rims of the two bights to the straight segments of the continuations of the standing ends and the tails. It is exactly the same rationale I follow in the tying method I have presented, probably because it has been imprinted in my brain then, right at the start, and old dogs do not learn new tricks !
    By a series of unfortunate events where I was as responsible as many other members of this Forum, I had deleted the original posts, so the description of the original ideas was lost. From this time, I keep in my files some relic pictures, remnants of some non-symmetric tangles of hitches, which escaped the incidence... The interested reader can see them in the attached files.
 
Title: Re: The Tweedledee bowline
Post by: alpineer on July 21, 2013, 09:40:07 PM
Lamenting the MWK's unsuitability as a climber's tie-on - as I love it's wonderful symmetry - lead me to re-routing the ends and discover the Tweedledee form. I suspect this is how Roger E. Miles originally came upon the knot.

   On the contrary, I am sure he did not come upon this knot that way !  :)
   He was just trying to tie all the possible simple symmetric bends there exist - and I know it, because when I re-discovered it, I was trying the same thing, being unaware of his book... and because he has told me so !  :) 
   I remember very well how I came upon it, 3 1/2  years ago - which was by systematically applying an anything but "random" method, as I was accused too easily by some "founding fathers" here... who were unable to "see" the method under the madness  :) . I simply collected all the symmetric hitching tangles, and tried to connect them one-to-one in every possible way. I started from the shape "8" overhand knot, the fig.8 knot, the Clove hitch, the double overhand knot / Strangle, the Constrictor and the Pretzel ( which is less symmetric than the others) - and I had connected each one of them to each one else, in every symmetric way I was able to figure out. That is, plain dumb, systematic work, that does not need any imagination to be accomplished ! Of course, the most interesting cases were the symmetric ones, where the two links were identical. The particular knot, the Tweedledee ( I had called it the "88" bend at that time, for obvious reasons ), and the somewhat similar topologically but completely different geometrically Oyster bend, were rather easy to tie. I remember that the problem was how to keep each link in one piece, by encircling/connecting the curved segments of the rims of the two bights to the straight segments of the continuations of the standing ends and the tails. It is exactly the same rationale I follow in the tying method I have presented, probably because it has been imprinted in my brain then, right at the start, and old dogs do not learn new tricks !
    By a series of unfortunate events where I was as responsible as many other members of this Forum, I had deleted the original posts, so the description of the original ideas was lost. From this time, I keep in my files some relic pictures, remnants of some non-symmetric tangles of hitches, which escaped the incidence... The interested reader can see them in the attached files.

X1,

You seem so willing to misunderstanding. I do not doubt what you say Mr. Miles' was trying to do and not searching for a climber's tie-on. I'm only suggesting in his endeavor to find all possible symmetric bends that he came upon the Tweedledee via transformations of the MWK (a well-known symmetric form). Now, enough of this, please.
BTW, did you know that it takes a few words only to state otherwise?   
Title: Re: The Tweedledee bowline
Post by: X1 on July 21, 2013, 09:58:08 PM
   You seem so willing to misunderstanding.
   
   You misunderstand, even if you are not willing to !  :)

BTW, did you know that it takes a few words only to state otherwise?   
   
   I have tried a few words, I have tried many words, but I have not seen much difference ! You still misunderstand...

...he came upon the Tweedledee via transformations of the MWK (a well-known symmetric form).

  So, let me try ONE word :
   
   NO
 
   (  No, he did NOT come upon the Tweedledee via transformations of the MWK (a well-known symmetric form).)

   Now, enough of this, please.

   Now, enough of this, please.
Title: Re: The Tweedledee bowline
Post by: alpineer on July 21, 2013, 10:05:57 PM
   You seem so willing to misunderstanding.
   
   You misunderstand, even if you are not willing to !  :)

BTW, did you know that it takes a few words only to state otherwise?   
   
   I have tried a few words, I have tried many words, but I have not seen much difference ! You still misunderstand...

...he came upon the Tweedledee via transformations of the MWK (a well-known symmetric form).

  So, let me try ONE word :
   
   NO
 
   (  No, he did NOT come upon the Tweedledee via transformations of the MWK (a well-known symmetric form).)

   Now, enough of this, please.

   Now, enough of this, please,
   
   

Fine then. I understand.
Title: Re: The Tweedledee bowline
Post by: X1 on July 21, 2013, 10:48:44 PM
Fine then. I understand.
   I am sure you can, but it seems that sometimes you do not.
   I have read Miles book as carefully as I could, and I believe I know his method. He DOES NOT start from well known symmetric knots, and proceed by transforming them, as you claim. He starts by the matrices that represent symmetric 2D diagrams of  EACH LINK, and then he superimpose those two links, paying attention to the kind of symmetry of the end result. He distinguishes three kinds of symmetry, and the Tweedledee symmetry obeys the higher of them: it is symmetric along two perpendicular to each other axes : he calls the bends which obey that symmetry "triple symmetric". The 2D diagram of the Tweedledee bend, which I have re-drawn in KnotMaker and posted in this thread, is quite complex, and it can not be used as a basis for an easy to remember tying method ( I have tried it ). Even when Miles describes tying methods, he relates the Tweedledee bend with the Dee bend, which I have also shown in this thread . And the Dee bend itself to the Harness bend... NOWHERE in his line of thought or his sequence of tying methods does he relate the Tweedledee bend with the Matthew Walker bend, for KnotGod s sake ! Read his lips : " To tie [ the Tweedledee bend ] , first tie A10 [ the Dee bend ], then insert free ends symmetrically." Now, read his lips for the Dee bend : " As with A8 [ the Harness bend], a tying method begins with cords aligned in opposite directions, with four crossovers ( over, under, over, under ). Symmetric insertion of the free ends yields the triply symmetric TWEEDLEDEE bend."
   ALSO, he examines the Matthew Walker bend in a completely different way, as the first implementation of Ashley s tying method, at ABoK #1426. He calls all the knots in this sequence by Ashley s name, generalized, as N - FOLD OVERHAND BENDS. This method is related to the Oyster bend, NOT to the Tweedledeee bend. ( p. 124, p.125 ). The Oyster bend is topologically different from the Teedledee bend - its "diagonal elements" are on the outer shell, not in the inner core of the knot.
   WHERE IS THE TRANSFORMATION OF THE MATTHEW WALKER, THAT SUPPOSEDLY MILES FOLLOWS TO GENERATE THE TWEEDLEDEE BEND ? WHERE IS THE INVERSE TRANSFORMATION ?
 
   You seem too quick to dismiss my willingness and/or ability to understand - you have done it again (1), and you keep doing it now. I have not seen this kind of behaviour by you against any other member of the Forum. Am I sooo mean and dumb, I wonder... :)

1.
...don't call me in the morning. ;D . Why do you insistently belabor other's statements with your incessant grandstanding? It's not just about you.
http://www.wisegeek.org/what-is-grandstanding.htm#slideshow  (http://www.wisegeek.org/what-is-grandstanding.htm#slideshow)
 
 
   
Title: Re: The Tweedledee bowline
Post by: James Petersen on August 07, 2013, 06:43:55 AM
I have been playing with the tweedledee loop/bowline/bend and have settled into a method which seems, to me, quite straightforward and not to fiddly to tie. It is similar to what Ruby has suggested, but begins in a different orientation.

I happen to like X1's initial naming of the knot the "88" bend, also for obvious reasons. In Mandarin Chinese, the words "eight eight" are homophones with "father/father's" and the word for "knot" is the same as "day/holiday".  In Taiwan, Father's Day is celebrated on August 8, and "8 8 knot" and "father's day" sound exactly the same, hence the name of the video.

https://archive.org/details/FathersDayKnot (https://archive.org/details/FathersDayKnot)

-- JP
Title: Re: The Tweedledee bowline
Post by: X1 on August 07, 2013, 08:00:09 AM
   Thank you J.P.
   You should had posted this video tomorrow !  :) 
   The tricky part is at 0.30 , where you pass the working end in between one riding turn and one finger.
    I had never tied this knot on such small line ! I use stiff kernmantle lines used for rescue and climbing - where the curves are always smooth and wide. With stiff ropes, the single hairpin, U turns, and the double hairpin, S turns, are easy to follow, so the knot is formed and held in place rather easily.
   I know that knot tyers will always tie the same knots in different ways ! I just prefer to tie the knots following a mental image that is related as much as possible to the geometry and the structure of the final, tighten knot. As I tie this knot, the two "8" s are always clearly visible, and they remain symmetric to each other during the whole tying procedure. Perhaps I prefer such slow / dumb methods because the hard disk of my memory is almost full, so there is not enough free space left for new tricks !  :)
   
   
Title: Re: The Tweedledee bowline
Post by: Ruby on August 07, 2013, 01:54:16 PM
well , I think  the structure of the final, tighten knot is more like two double loops, not two flat 8. it's such a round knot.


and see here , I just double double it... :D


(http://igkt.net/sm/index.php?action=dlattach;topic=3989.0;attach=11852;image)

(http://igkt.net/sm/index.php?action=dlattach;topic=3989.0;attach=11854;image)
Title: Re: The Tweedledee bowline
Post by: X1 on August 07, 2013, 02:43:51 PM
the structure of the final, tighten knot is more like two double loops, not two flat 8. it's such a round knot.

  The first "flat" 8 starts to curl / bend, the very moment you make the working end of the second link of the bend ( or of the bight component structure of the eye-knot ) penetrate the two nipping turns of the first. Yes, it is round, and the most important thing it s that is very compact and dense - itsvolume / bulk is very small, considering the total rope length it consumes.

see here , I just double double it... :D

  Tweedledoubledee, or Tweedoubledee, for short !  :)
Title: Re: The Tweedledee bowline
Post by: James Petersen on August 07, 2013, 08:05:12 PM
   Thank you J.P.
   You should had posted this video tomorrow !  :) 
   The tricky part is at 0.30 , where you pass the working end in between one riding turn and one finger.
  ...

This part is actually quite simple when I am not trying to make a video of the procedure.  The working end simply follows parallel with the part under the riding turns.

Making the video was rather awkward, so things didn't flow as smoothly as they normally do.  I was sitting on two stools with a tripod between my legs, and the top of the tripod and the camera/phone directly in front of my chest, between my face and my hands. My attention was split between watching the screen and tying the knot. Tying withe the same method and using the same line I normally tie the knot in between 15 - 20 seconds.

When tying with this method, I also find that I can better observe the formation of the second "8" than I can when I tie with the "8" laid out in my hand -- the two parallel legs keep me from seeing what is going on, much like the two legs of the collar on a bowline obscure the nip when viewed from the "front".  ;)

-- JP
Title: Re: The Tweedledee bowline
Post by: X1 on August 07, 2013, 08:19:35 PM
   I was sitting on two stools with a tripod between my legs, and the top of the tripod and the camera/phone directly in front of my chest, between my face and my hands. My attention was split between watching the screen and tying the knot.
:) :) :)
much like the two legs of the collar on a bowline obscure the nip when viewed from the "front".  ;)
:) :) :)
   However, in this case, following my dumb method, one can be helped by the perfect symmetry, and for-see / anticipate what happens to one part of the one link he can not see because it is hidden, by what happens to the corresponding symmetric part of the other link that is shown ( by definition, two symmetric parts can not both be hidden in a "front" and a "rear" view, at the same time !  :) )
Title: Re: The Tweedledee bowline
Post by: Ruby on August 08, 2013, 11:24:19 AM
tweedledee bend , and its 99% similar twin tweedledum bend , both easily tied by retucking a what knot 1406.
Title: Re: The Tweedledee bowline
Post by: X1 on August 08, 2013, 12:00:42 PM
and its ...similar to...
both tied by retucking a ...
   
   Nooope, two topologically different knots are NOT similar ! They might even not be similar if they are topologically identical, but geometrically / structurally quite different, like the "bistable knots" (1)
   The fact that they can be tied by re-tucking the same knot, is of no importance whatsoever, regarding their "similarity". See how many completely dissimilar bends can be tied by re-tucking the Reef knot (2)(3), the Thief knot (4), or a certain symmetric Carrick mat (5).

1. http://igkt.net/sm/index.php?topic=4201 (http://igkt.net/sm/index.php?topic=4201)
2. http://igkt.net/sm/index.php?topic=3204.msg19380#msg19380 (http://igkt.net/sm/index.php?topic=3204.msg19380#msg19380)
3. http://igkt.net/sm/index.php?topic=2826.msg19395#msg19395 (http://igkt.net/sm/index.php?topic=2826.msg19395#msg19395)
4. http://igkt.net/sm/index.php?topic=3611 (http://igkt.net/sm/index.php?topic=3611)
5. http://igkt.net/sm/index.php?topic=3086.msg18494#msg18494 (http://igkt.net/sm/index.php?topic=3086.msg18494#msg18494)
Title: Re: The Tweedledee bowline
Post by: Ruby on August 08, 2013, 05:24:44 PM
Oh, no need to ignore their similarity :D

they sure are not same, but there's remarkable similariry,
and so they're named tweedledee and tweedledum,
which means twins , hard to distinguish, by looking. 

the diff point is inside the knot knub, an additional crossing


Title: Re: The Tweedledee bowline
Post by: X1 on August 08, 2013, 06:01:09 PM
they sure are not same, but there's remarkable similariry, and so they're named tweedledee and tweedledum,
which means twins, hard to distinguish, by looking.
 
  Their claimed "similarity" is only skin deep. I will never call "similar" two knots of different topology ! Is the 0 similar to 1 ? Is the sphere "similar" to a torus / donut ? Especially in this case, the one bend can be turned into a PET eye-knot, while the other can not. Big, HUGE difference ! The "remarquable similarity" and the names chosen by R.E.Miles were unfortunate mistakes ! The Teweedledum ( M. B 24 ) is more "similar" to the "Flat square knot ( M. B 29 ).
   The road to call "similar" all the knots that it is hard to distinguish by looking ( but very easy by tying or untying...), is a very slippery one ! Imagine how many completely different knots, indeed, things, you will be forced to call "similar" !
   
   For a FINE, in depth exposition on the issue of the so-called "similarity" of various bends, see :
   http://charles.hamel.free.fr/knots-and-cordages/Investigation_6.html (http://charles.hamel.free.fr/knots-and-cordages/Investigation_6.html) 
Title: Re: The Tweedledee bowline
Post by: Ruby on August 09, 2013, 03:05:10 PM
Tweedledum bend is formed by retucking a what knot 1406(grief?)


B29 or abok 803 is formed by retucking a reef knot, very very very difficult to untie
Title: Re: The Tweedledee bowline
Post by: X1 on August 09, 2013, 03:17:43 PM
B29 is... very very very difficult to untie
  The "Oyster bend", which is just the Tweedledee bend with the "diagonal elements" on the outer mantle of the knot ( and can be tied with a corresponding tying method ) is much more difficult to untie ! In fact, it is the most tight / jamming knot I know ! So, you see, a "minor" detail can transform a prince into a frog, and vice versa. "Similarity" of knots is a notion that does more harm than good.