International Guild of Knot Tyers Forum

General => New Knot Investigations => Topic started by: X1 on April 18, 2013, 04:41:29 PM

Title: Two pairs of pet TIB twin eyeknots
Post by: X1 on April 18, 2013, 04:41:29 PM
   When I had presented those two crossing knot + overhand knot post-eye-tiable eyeknots (1)(2) { the OH knot used as a hitch, in the sense of ABoK#1821 }, I had deliberately ignored some "similar" knots I had also tied at the same time, where the rim of the overhand knot is wrapped around both eye legs (3). I thought that this rim/collar/bight, trying to keep those legs crossed, would suffer during ring loading,  it would be forced to widen, and/or it would remain loose - so I decided that the eye legs should better leave the knot s nub from different exit points. If we relax this condition, we enter into a broader class of bowline-like loops, where the overhand knot is now tied around the "base" of both eye legs - while it still remains entangled within the crossing knot in the same secure way ( a way that forces its tail to pass through, and be squeezed in, the most constricting area of the knot snub, in between the standing part s and the returning eye leg s first curves ). These eyeknots are also simple, very stable and very secure knots - although, for unknown to me reasons, they have not yet received the attention they deserve by the knot tyers.
   Some days ago, Alan Lee has shown one of those knots (4), so I grasped the opportunity to study them again, more carefully. Surprize !  :) I had discovered that at least two pairs of very "similar" such crossing knot + overhand knot loops, happen to be TIB eyeknots - a fact I believe sheds some new light on them. Being so simple, most or even all of them would have been tied at the past, I guess, but I doubt that they were ever considered or presented as a group, as in this thread. The interested reader would find out how one can go from the one to the other reversing the clock-wise or counter-clockwise direction of the returning eye leg s turn/collar/bight around the "base", and/or the side by which the tail enters into the knot s nub.

1. http://igkt.net/sm/index.php?topic=3944.msg23427#msg23427
2. http://igkt.net/sm/index.php?topic=3944.msg23429#msg23429
3. http://igkt.net/sm/index.php?topic=4095.msg24592#msg24592
4. http://igkt.net/sm/index.php?topic=4125.msg27230#msg27230
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on April 18, 2013, 04:43:24 PM
  Same pictures, inversed colours ( white background).
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on April 18, 2013, 05:55:59 PM
   For an easy comparison, here are two other Crossing knot + Overhand knot post-eye-tiable knots (PET), which are not tiable-in-the-bight (TIB).
   ( The lower (L), and the higher (H) knots at the "front" view, have been flipped at the "back" view ).
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on April 25, 2013, 05:54:30 PM
   A way of tying the A pet Twin, as a TIB loop. Form three bights. Reeve the third one through the first one, half-way ( first picture). Then, reeve the second one through the third one all the way ( second picture ).
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on May 27, 2013, 02:38:12 PM
   I tried the pet TIB (A) eyeknot against its main TIB rival : the Angler s loop. In the 6 mm cord shown at the attached pictures, under cyclic loading ( = jumping with by full body weight... :)), I was able to make the Angler s loop jam, but not the pet TIB eyeknot. In fact, while the nub of the former was made very compact and rock solid, I was always able to untie the later quite easily, by manipulating=twisting its "lower" collar ( the collar around the eye legs ), which remained much softer. The corresponding collar around the eye legs of the Angler s loop did not yield to this or any other untying technique I hade tried. The reason in simple : the collar around the eye legs of the Angler s loop is directly connected with the most tensioned segment of the standing part, while the corresponding collar of the pet TIB loop is not. I believe that this is a general characteristic of most, if not all the crossing knot eyeknots - the nipping structure of those knots is not so powerful as the single simple nipping loop of the common bowline, but it is much more stable and it can be secured against the main danger the bowlines face under heavy loading, the 'opening" and the subsequent degeneration into an helix of their nipping structure, much easier. It is a pity that knot tyers have not yet noticed the stability and safety a carefully designed crossing knot based pet eyeknot can offer.
    To the interested reader, I recommend to tie this very easily tiable loop - either in-the-bight or in-the-end - and comment about it here. In my previous post, I have shown what I believe is one very simple TIB tying method , but I do not doubt that there might be others, equally or even more easy to remember and to follow.
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: SS369 on May 27, 2013, 03:03:10 PM
Thank you X1.

One thing I notice and causes me to suspect something, is the movement of the nipping loop around the entry stem as strain is increased. What I suspect is that this area of movement will be the location of breakage due to friction heat along with compression of that small place of contact.

The subject of untie-ability is a tough one unless we set a standard(s) of force/load versus diameter/material elasticity. Force retention of soft cordage is a game changer sometimes.

SS
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on May 27, 2013, 03:41:25 PM
Thank you SS369,

   The subject of untie-ability is a tough one unless we set a standard(s) of force/load versus diameter/material elasticity.

   I have suggested that we use ONE measure only, that of the untie-ability or not under 50% of the rope s ultimate strength.
   My point in the previous post was that this pet TIB eyeknot does not jam, after the same amount and number the (cyclic) loading where the Angler s loop does. However, I have not confirmed this at the 50% of the rope s strength - which I do not know if it is above or below the loading I have applied.   

   
compression of that small place of contact.

   Notice that the tail is located in between the standing part s and the eye leg s first curves, as a "bumper" that dissipates the load across a greater area there. Due to the fact that those two curves embrace each other, around the pivot-like tail, their contact area is not small. Now, the contact area between the standing end and the rim of the crossing knot does not matter much, because those two segments are not squeezed upon each other - under heavy loading, they barely touch each other. The "heart" of the loading, which will generate the heat, is located around the penetrating-the-two-curves tail.
   Would you, please, try it with the famous HPPE ropes of yours ?  :) I guess that, with those slippery ropes, you should better pull the tail with some force before loading, so the knot s nub will have as a compact form as possible right from the start. 
   Did you follow the TIB method I have shown, with the three interlocked bights ?
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: SS369 on May 27, 2013, 11:51:49 PM
Hi X1.

I have just tied the PET TIB (A) using the Titan 5.5mm cord with the three interlocked bight method (Very easy!).
It ties up nicely and with a 200 lbs. approximate load I was able to flex it loose and untie. Not the 50% for sure.

I still suspect the area of the incoming rub to be the weak point. As the load through the nipping collar increases, the friction on the stem will get severe. Even with the knot SStightened it has some movement that I feel will continue to destruction as the 50% plus is exceeded.

BTW, it seems to be a winner as a mid-span loop too.

SS
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on May 28, 2013, 12:41:56 AM
   Not the 50%, for sure.

   Dan Lehman has pointed out that the 50% is too much, for knots tied on HDPE - their ultimate strengths can not reach such percentages. So I guess that, regarding knots tied on those very strong materials, we should be satisfied with an untie-ability of even a "mere" 1/3 = 33.3%.

   I still suspect the area of the incoming rub to be the weak point. As the load through the nipping collar increases, the friction on the stem will get severe.

  I misunderstood you, I thought you were talking about pressure, not friction. Regarding friction, you may be right. The standing part is almost tangent to the rim/stem of the crossing-knot-made nipping structure, so the surfaces of the two segments at their small contact area may suffer, indeed.
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: SS369 on May 28, 2013, 01:08:29 PM
I think that area will indeed have and be a high pressure location as well. Compression at the stem to collar contact will be great, as in many other eye knots.

Yes, according to manufacturers information, HDPE does not like bends in the fibers. Stronger than steel when straight or gently curved.

SS
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on May 28, 2013, 01:46:20 PM
HDPE does not like bends in the fibers. Stronger than steel when straight or gently curved.

  Why ? I do not understand this...The Dyneema/Spectra fibre itself is not inflexible, is it ? Perhaps this is due to the patterns used to weave those fibres together - 8 or 12 braids, that can not be tensioned evenly when they have been bent ?
  As mentioned in (1), ancient writes describe ropes in great detail, but, when it comes to knots, they are notoriously silent. It seems that, with modern writers, what is happening is the exact opposite ! One can see this tendency in this Forum, too. Too much talking about knots, and almost nothing about the things on which knots are tied, and which enable the existence of knots in the first place, the ropes. It would be great if the members of this Forum who happen to know more about ropes than the average knot tyer, share their knowledge with us - perhaps a Section named " Ropes : properties, materials and structures ", something like this, would trigger some response ?

1. http://nautarch.tamu.edu/pdf-files/Charlton-MA1996.pdf   
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: SS369 on May 28, 2013, 11:37:55 PM
HDPE does not like bends in the fibers. Stronger than steel when straight or gently curved.

  Why ? I do not understand this...The Dyneema/Spectra fibre itself is not inflexible, is it ? Perhaps this is due to the patterns used to weave those fibres together - 8 or 12 braids, that can not be tensioned evenly when they have been bent ?

I think that this statement > "low elasticity translates to low toughness." sums part of it up to me. Read the article at http://en.wikipedia.org/wiki/Dyneema (http://en.wikipedia.org/wiki/Dyneema) and ponder about the long chain molecules.

SS
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on May 29, 2013, 12:43:49 AM
"low elasticity translates to low toughness."

   I hope you will elaborate on this a little more in your book !  :)  :) I do not understand how flexibility is related to elasticity, and also how elasticity is related to ultimate strength... Nylon is much more elastic than polyethylene, yet it is not much stronger. Also, I think that if a material is not flexible ( and so it can not be bent ), it breaks - like ceramics do. Certainly HDPE fibres do not break when bent, they just lose a considerable portion of their maximum tensile strength - but right afterwards, when they are straightened again, they return to their previous state regarding this strength, is nt it that so ? Anyway, I reckon that if my knowledge about knots has reached 1 ( out of 10...), my knowledge about ropes is still around 0.01... :)
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: SS369 on May 29, 2013, 01:03:36 AM
Give this a read. http://stuff.mit.edu/afs/athena.mit.edu/course/3/3.064/www/slides/Advanced_Fibers_MRS.pdf (http://stuff.mit.edu/afs/athena.mit.edu/course/3/3.064/www/slides/Advanced_Fibers_MRS.pdf)
On the first page - Mechanical properties of Fibers.

SS
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on May 29, 2013, 09:16:00 AM
   Thanks. Go on !  :)

The extension of the chain is determined by the stiff covalent bonds, while the shear deformation is governed by the much weaker interchain bonds.Thus, the shear failure of the interchain bonds, not the fracture of the covalent bonds in the chain, is the limiting factor for the strength of these fibers
However, because of the rather weak chain-to-chain attractional van der Waals forces, polyethylene fibers undergo creep and display poor compressive load-bearing behavior. These issues, combined with the poor adhesion of polyethylene, make these high-strength fibers unsuitable as reinforcing fibers. These fibers perform well only for short durations or for impact loading.
...the bonding between the chains in polymer fibers is established by van der Waals and hydrogen bonds. These bonds show elastic behavior up to the yield strain in the tensile curve of the fiber. For larger strains, some loosening or yielding of the interchain bonding occurs, resulting in the nonelastic (plastic) behavior of the fiber. This "softening" of interchain bonding allows stress relaxation by some local movement of the chains around flaws and impurities without severely deteriorating the creep behavior of the fibers. After unloading of the fiber before breakage, all interchain bonds are restored to their original strength.

Title: the pet loop
Post by: X1 on June 03, 2013, 11:27:21 PM
   Notice two things :
   1. The second end ( at the right side of the picture ) of the first "small" bight ( the bight that is going to form the nipping loop ) goes "over" its first end ( at the left side of the picture ), while the second end ( at the right side of the picture ) of the last "small" bight ( the bight that is going to form the collar around the eye legs ) goes "under" its first end ( at the left side of the picture). So, if the first bight is a "right-hand" one, the last is a "left-hand", and vice versa.
   2. Both reeved bights should penetrate the stationary ones going from the same, their "back" side, to their "front" side, as shown at the second and third attached pictures.
 
   I have no doubt that this loop is much better than the Span loop ( ABoK#1049 ) - the tail is secured/locked in between the first curves of the standing part AND the returning eye leg ), but, judging from past experience, I reckon that this would need 60, at least, years to be understood and appreciated by Ashley s devoted followers :).     
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on June 09, 2013, 02:00:13 PM
   I believe that people accustomed to the tying method of the Span loop ( ABoK#1049) shown by Ashley, would probably prefer the similar tying method of the pet loop A shown in the attached pictures.
  There are two possible advantages of this method : First, we start from an axially/mirror symmetric form ( the one shown in the first picture ) - therefore we can easily tie and inspect the one "left-hand" bight and the one "right hand" bight we are going to need. ( The "first" will become a part of the main nipping loop, and the "last" will become a part of the collar around the eye legs.) Second, we start from the initial stage / image of the common bowline, which is familiar to most knot tyers. Ashley did the same thing in ABoK#1037 and ABoK#1049.

   
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: struktor on June 09, 2013, 08:27:07 PM
My suggestion.

Title: Re: Two pairs of pet TIB twin eyeknots
Post by: struktor on June 09, 2013, 08:29:49 PM
What is the name of this knot?
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: roo on June 09, 2013, 10:14:59 PM
What is the name of this knot?
It looks to be just a Butterfly Loop:

http://notableknotindex.webs.com/butterflyloop.html

Just dress it a little.
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on June 09, 2013, 10:22:55 PM
   Hi Struktor,

   The loop you show is an "Englishman knot" ( an Alpine Butterfly loop, in particular ) - one variation of those knots, because we can tie quite a few similar but distinct ones. The main characteristic of this family of eyeknots, is the two interlinked overhand knots, each tied between an end and an eye leg. Those two overhand knots can be interlinked in a number of more or less symmetric ways :  at the end, the tight knot, the "first" overhand knot can be "above" and the "second" "below" the other, or they can remain "side-to-side" to each other. Of course, the interesting thing in this particular loop is that it is TIB (1). However, it is not a bowline-like, post-eye-tiable ( PET ) eyeknot, so it is not as versatile as in many other bowline-like eyeknots of about the same complexity. I always start from the demand of a PET eyeknot - not a TIB eyeknot -, and, in this thread, I was happy to show that we can have our cake and eat it, too - but the cake is always the same, the bowline, not a TIB loop.
   Having said that, there is no question that most "Englishman knots" are so symmetric ( because of those two more or less symmetrically placed overhand knots ), that they are very well balanced, and good looking, indeed.
   ( Even if you wish to place and fix the two eye legs in the relative position to each other you show, you do not need the "third" closed bight at picture #3 - you can well re-arrange them at the very end. )

http://daveroot.atspace.cc/knots/Knots_SingleLoops.htm#AlpineButterfly
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: Ruby on June 10, 2013, 03:53:31 AM
seems easy, yet much difficult.

can not tie it without looking at the picture after trying so many times :(
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: struktor on June 10, 2013, 06:34:17 AM
Thanks for the information.

May be tests
http://www.youtube.com/watch?v=s3fHYGY3YTo
http://www.youtube.com/watch?v=GDJ3QjvRZT0
http://www.youtube.com/watch?v=0Snpthv91Oo

Struktor
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on June 10, 2013, 10:04:43 AM
can not tie it without looking at the picture, after trying it so many times :(

At
http://daveroot.atspace.cc/knots/Knots_SingleLoops.htm#AlpineButterfly
there are 5 other methods of tying this knot - I can think of 5, at least, different ones, and, if you search in this Forum, you will find even more !  :) Do not look at the pictures : try to "see" and understand the structure of the knot, so then you will easily be able to reproduce it following any "method" that suits you better - just as you did with the Jug Sling knot.
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: Ruby on June 10, 2013, 02:17:35 PM

...
 if the first bight is a "right-hand" one, the last is a "left-hand", and vice versa.
...


   I believe that people accustomed to the tying method of the Span loop ( ABoK#1049) shown by Ashley, would probably prefer the similar tying method ...


Ashley did the same thing in ABoK#1037 and ABoK#1049.
   



at first I didn't get this.

now I got it.

so , you first post a left handed one,
 and then you post the first step to tie a right handed one.


I see . it's almost the same method as span loop #1049,
just add a twist to the top loop and the bottom loop.
(http://ww1.sinaimg.cn/mw1024/55663898tw1e5jcoai7wqj20i80e2jtj.jpg)



now it's much easier :)

the tail is really "locked in between the first curves of the standing part AND the returning eye leg"!


Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on June 10, 2013, 03:01:24 PM
it's almost the same method as span loop #1049,

   I had added the first picture, where the two bights have not approached each other yet, because it shows their mirror symmetry, right from the start.  So, all you have to do, is to insert the "last" bight ( the one at the right side of the picture ) half way through the "first" bight ( the one at the left side of the picture ), without twisting it - just by moving it parallel to itself. Doing this, you avoid the need to twist it after you had inserted it into the "first" bight, because, if you do the twisting at this stage rather than right from the beginning, you run the danger to twist it the wrong way...
   Notice that I decided to show this method only after you had shown your "similar" method - meaning, starting from the first step of tying a "common" bowline - for the Jug Sling. In general, I do not show specific methods of tying knots, because it seems that every knot tyer ties the same knots in a different way. However, in this case, a method that starts from the first, familiar stage of tying a "common" bowline should perhaps be suggested, because it reminds us what this eyeknot really is : a bowline-like, post-eye-tiable eyeknot ( PET ), which happens to be tiable-in-the-bight (TIB), too. One can tie it as an end-of-line bowline-like loop, or as a midline loop, according to the circumstances. As I said, in practice ( when I have am not forced to tie it through a ring, but only around a bollard), I have seen that I prefer to tie it as a midline loop, even at the end of the line - perhaps because I have been tying bowlines all my life, and I now want a little change... :)
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: SS369 on June 10, 2013, 03:07:32 PM
Struktor.

Thank you for the links.
I only wish we had more like this one > http://www.youtube.com/watch?v=s3fHYGY3YTo (http://www.youtube.com/watch?v=s3fHYGY3YTo) !

SS
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: roo on June 10, 2013, 03:12:52 PM
I only wish we had more like this one > http://www.youtube.com/watch?v=s3fHYGY3YTo (http://www.youtube.com/watch?v=s3fHYGY3YTo) !
How often does anything like this occur in real-world use, especially with the size of rope shown?
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: Ruby on June 10, 2013, 04:03:55 PM
...
 So, all you have to do, is to insert the "last" bight ( the one at the right side of the picture ) half way through the "first" bight ( the one at the left side of the picture ), without twisting it - just by moving it parallel to itself. Doing this, you avoid the need to twist it after you had inserted it into the "first" bight...

well, I added a twist to the last bight ,
just to avoid the need to twist it after  I had inserted it into the "first" bight.
anything wrong?

at first I tried to just insert the last bight without twisting,
but then I find it still need additional twisting to dress it right.


" without twisting it - just by moving it parallel to itself."

I see. the point is to get it parallel , either twist before or move it after

at first I didn't know, and you didn't say, that "all you have to do, is to insert the last bight..." :)
now  I think I get it. both easy. much easier than that three loop method.
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on June 10, 2013, 06:20:00 PM
well, I added a twist to the last bight ,
anything wrong?

   I believe that it is easier and safer, too ( you do not run the danger to twist the first or the second bights the wrong way...) if you form and inspect both bights at the same time, right from the start - so that you will not have to "add" a twist to the "last" bight at a later moment.. I mean, it is perhaps easier, simpler and safer if you retain the God-given mirror symmetry of our hands during as much of the tying procedure as possible. I do not know if I will be able to describe it even by pictures, but I will give it a try ;
   1. Grasp the line with both hands. Place your index fingers under the line.
   2. Twist both your wrists in the easiest way - that is, the way that retains the mirror symmetry of your hands. The line will be wrapped around your index fingers, and it will form the two mirror-symmetric bights.
   3. Now you have to pull your index fingers out of the bights, and start using your thumbs - octopuses should have been a newer model, evidently !
   4. Hold the crossing points of the two bights between your index fingers and your thumbs, and translate the one bight towards the other - there is no need for any additional twist.
   5. Now you hold the two bights, you can easily push the "last" through the "first". When you will do it, you will grasp the half-reeved "last" bight with the thumb that was used to hold the "first" one, so your right hand would be free to grasp the main bight of the loop, reeve it through the "last" bight, and complete the tying. Alternatively, you can hold both bights between the index finger and the thumb of your right hand, and use the left hand to reeve the main bight. I prefer to use the right hand for this, so that, when I have formed the loop, I can keep holding the standing end with the same hand I was holding it in the previous phase, and dress it with my "good" right hand...

   
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on June 10, 2013, 06:21:08 PM
   5. The "last" bight through the "first" one.
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: SS369 on June 10, 2013, 08:32:16 PM
I only wish we had more like this one > http://www.youtube.com/watch?v=s3fHYGY3YTo (http://www.youtube.com/watch?v=s3fHYGY3YTo) !
How often does anything like this occur in real-world use, especially with the size of rope shown?

Good day roo.

Perhaps if this was done more often, the testing mind you, we would have something else to talk about besides conjecture and opinion.
I believe that the testing as shown (youtube link) would be applicable to smaller sized ropes of similar construction not just the 10.5mm used for rescue work and could benefit knot tyers worldwide.

I can think of quite a few instances where the breaking strength of ropes/cords/webbing  is approached. Regardless of the safety warnings people will use what they have sometimes. So, it would be nice to gather more knowledge of the mechanism of destruction within the knot(s).

If you are not interested, then by all means please ignore the links or further data.

SS
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: roo on June 10, 2013, 09:03:27 PM
I can think of quite a few instances where the breaking strength of ropes/cords/webbing  is approached. Regardless of the safety warnings people will use what they have sometimes. So, it would be nice to gather more knowledge of the mechanism of destruction within the knot(s).
I'm thinking that the intersection of people who disregard safety warnings and destroy big expensive ropes rather than use the right size and will also review these links is going to be pretty small.   ;)

It might yield data or insights for smaller, disposable stuff where rupture is a more common event.  With smaller rope, they'd could afford to do more tests.
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: SS369 on June 11, 2013, 12:23:31 AM
Sorry for drifting off topic X1. Just thought the link showed testing that the IGKT should do or be aware of.

SS
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: Ruby on June 11, 2013, 01:35:44 AM
I think it's easy to get the 5th pic's stage

after your 5th step,  I think I'd push the leg of the main loop with left thumb
to change the position with the other leg, before the final inserting.
(http://ww4.sinaimg.cn/mw1024/55663898tw1e5jw9n4tc9j20rs0foq4u.jpg)

as 1049,  if just do the final inserting without twist the main loop,
the two legs (yellow parts) need additional dressing.
(http://ww2.sinaimg.cn/mw1024/55663898tw1e5jw9mrg3pj20go09e3zo.jpg)

maybe change the two yellow parts position after inserting?
maybe no need to change?


anyway, now it changes from a difficult knot to a pretty easy one.


interesting.

Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on June 11, 2013, 09:41:12 AM
maybe no need to change?

Precisely. As with the Span loop. I forgot to tell you, in my previous post, that you have only to flip the main bight over the tangle, and insert it into the half-reeved "last" bight from the 'back" side - no need to twist it before you reeve it ( as you show at your picture with the red arrow). You can always dress it afterwards, when you will pull the tail to tighten the knot you will be holding with your left hand by the standing end.

I think it's easy to get the 5th pic's stage

   Of course, but there is a purpose in my suggestion to follow this sequence if steps, and arrive at the mirror symmetric 3 rd stage...Notice that you can not twist your wrists ( well, you can not twist them easily, as I say...) the wrong way...so you do not run the danger to twist them the other, wrong way. Also, it is also easier, it comes more natural, if you twist your wrists in a mirror symmetric way - so you do not run the danger to tie two congruent , not mirror-symmetric bights.

   If you tie all the possible pet TIB loops that I have presented in this thread, you will see that they are not difficult : they are based on the simplest crossing-knot nipping loop, then the working part / returning eye leg first penetrates this crossing-knot loop and then turns around both eye legs ( makes the "lower" collar ) in every possible way, and then it goes through both the standing part s and the returning eye leg s "hooks" ( first curves ), so it is secured there, as a tail, in the most effective way. Understanding a knot makes any apparent "difficulty" disappear at once ! I have not tied those knots in "random" , as roo advocates ( and I will not be surprised if he believes this, too !  :) ). I had tied them by just following the straightforward reasoning I have described, which, if it is retraced, reveals that those knots are most "natural", and the simplest possible- so they are not difficult at all. Of course, there are people who are not able to understand this, and they will probably never be... For myself I can tell that I am not able to play a decent table tennis game ( among MANY other things I am not able to do...), although I have tried for many years !  :) However, I do not feel any inferiority complex about that !  :) 
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: Ruby on June 11, 2013, 10:10:20 AM
You can always dress it afterwards.

ok.


they are based on the simplest crossing-knot nipping loop, then
the working part / returning eye leg first penetrates this crossing-knot loop
and then turns around both eye legs
and then it goes through both the standing part s and the returning eye leg s "hooks"...


ok , I think I get it.

now keeping these instructions in mind,
I think I can tie this pet loop with one end.
and I did. it's just like tying a  bowline. (so it's really PET)

things get more interesting. :)
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on June 11, 2013, 10:32:52 AM
   Notice that the pet TIB B can be tied in a more secure form, if the path of the tail ( in relation to the standing part s and the eye leg s "hooks"/ first curves ) is similar to the path followed in pet TIB A ( i.e., if the tail is "locked" securely in between them ). I have chosen to present it in this less satisfactory form only because I wished to show it only as a "twin" to the pet TIB A, to complete the two "pairs" presentation - and in the other, more secure form, it was looking more "different" than the pet TIB A. Anyway, I think that the pet TIB A is the most easily tied one, while it retains all the useful characteristics of the two "pairs" set.
   Unfortunately, in the country I live most docks available to small fishing boats and sailboats have rings, not bollards - so I guess I will not be able to "show" the pet loop as often as my inferiority complexes dictate !  :) :)
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: Ruby on June 11, 2013, 10:36:25 AM
I  just tried to tie it as a PET bowline. see if it's right:

1
the working end first penetrates the nip loop. this is same first step as tying a common bowline
(http://ww4.sinaimg.cn/mw1024/55663898jw1e5kblkfhuuj20b40glwfh.jpg)

2
then turns around both eye legs (make a colloar at lower,  unlike a common bowline  )
(http://ww2.sinaimg.cn/mw1024/55663898jw1e5kblk4irzj20do0j0wgb.jpg)

3
note the "hook" made by  first curve and eye leg
I see this structure many times in this forum,  ( seems called "two U shape lock"??)
(http://ww3.sinaimg.cn/mw1024/55663898jw1e5kbljlfgvj20b40fg75g.jpg)


4
pull the tail throughthe "hook".
done.
(http://ww2.sinaimg.cn/mw1024/55663898jw1e5kbljao7hj20b40fp75d.jpg)
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: Ruby on June 11, 2013, 10:39:27 AM
acturally I think this is bowline like method is  more easier than that span loop like method, if right. :D

and,

seems that structure is called "opposed-bights nipping??

I think I saw it in that TackleClamp hitch.
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on June 11, 2013, 10:47:01 AM
see if it's right:

Nooope !  :) Start from a crossing-knot based nipping structure / loop, not the single nipping loop of the "common bowline !
All those 4 (5) knots are base on the same crossing knot s initial nipping loop.
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: Ruby on June 11, 2013, 10:51:47 AM
Nooope ! 

are you sure?

I checked again, and I think it's just the knot. where's wrong?
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on June 11, 2013, 11:02:31 AM
is this structure called "opposed-bights nipping??
I think I saw it in that TackleClamp hitch.

   It bears some resemblance, yes, but we can not say that is the same mechanism.
   In the oppose-bights nipping, ( that can secure the trucker s hitch tail, for example (1) ) all the four limbs of the two opposed bights are loaded at about the same degree - that is not the case here, because the two bights, although they are "opposed" , are "buried" inside the knot s nub, so their limbs are in touch with other segments, and dissipate much of the tensile forces running through them there.
   The thing one should always seek when he tries to prevent slippage, is to arrange the segments of a knot so they meet each other at the right angles, the right angle ! When segments of rope are squeezed upon each other while they form a right angle, they "bite" each other hard, so the friction forces are greatly enhanced. Doing this for the tail of a knot, is the most effective way to secure it.

1. http://igkt.net/sm/index.php?topic=1870.msg17364#msg17364
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on June 11, 2013, 11:12:44 AM
it's just the knot. where's wrong?

   Nothing is wrong with the knot !  :) It is wrong with the tying method : it is not the tying method I had described, that starts from a crossing knot s nipping loop ! Tying the knot like you did, the crossing knot structure is hidden, and it is revealed only after the last tuck. THIS is exactly what makes the knot seems "difficult", as you said ! I do not believe that knots should be tied as "puzzles"( see the way sailors used to tie the sheepshank, for example, the "parlor" method, ABoK#1162, or the way the Farmer s loop ( ABoK#1054) is tied in ABoK ), because that makes them look like some kind of "magic", of a magicians play, while they are just rope-made mechanisms, and their structures can be very easily understood - IFF we wish them to be so !  :)
   In short : those are not common-bowline-like loops based on the "common" bowline s single nipping loop, but crossing knot loops based on the nipping structure of a crossing knot loop. I believe it is better if the tying method reveals this right from the start, and does not involve the common bowline image. For other crossing knot loops, see (1).

1.  http://igkt.net/sm/index.php?topic=3467.msg24483#msg24483
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: Ruby on June 11, 2013, 11:21:44 AM
"Nothing is wrong with the knot ! "

I think this is enough.

I think it's just a simple tying method, for me at least.


tying a span loop is just like tying a farmer's loop, seems easy, yet hard to dress.

this method is easy to tie, and easy to dress.


so , as someone said, different tying method maks different knot, even the structure is the same?



Title: Re: Two pairs of pet TIB twin eyeknots
Post by: Ruby on June 11, 2013, 11:26:31 AM
well, as a PET loop, how do you tie it using one end?

I think I just got that bowline like method following exactly your instructions.

though acturally I don't get the concept of crossing knot.

is there any knot without crossing? ;D

strange knot words , just for me.

Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on June 11, 2013, 11:36:11 AM
different tying method maks different knot, even the structure is the same?

   No, I, for one, will not go as far as this... although I have seen instances where a different tying method can arrange the tails differently, so it can tie a different knot (1).
   However, I believe "simplicity" is a most complex thing !  :) A quick tying method may not be simple to understand, and I think that, if people start from a common bowline s initial stage, as you did, and tend to believe that those pet TIB loops are just more complex bowlines, they will not understand them - and they will not understand the bowline, either. The common bowline s nipping loop is a completely different thing than a crossing knot - based nipping loop... Therefore, it needs a collar, around the standing end, to remain stable, and to not degenerate into an open helix. The crossing knot loops are very different in this. They may be more convoluted at the beginning, and their nipping power may be less than the nipping power of a single nipping loop ( where the second limb runs directly into the eye), but they are, in a sense, self-stabilized, they are far more stable  : So they do not need a "proper" collar ! Big, huge difference !
 
   1. http://igkt.net/sm/index.php?topic=4128.msg24826#msg24826
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on June 11, 2013, 11:39:45 AM
acturally I don't get the concept of crossing knot.
is there any knot without crossing? ;D

   Crossing knots have two crossings !  :) ( well, almost...the standing part comes very close to itself two times, not only one, as in the "common" bowline s single nipping loop

   Tie the crossing knot-base loops shown in the reference I had mentioned in Reply #43, and you will get it at once !

P.S. At the attached picture you can see a crossing knot s nipping structure - no relation whatsoever with the "common" bowline s nipping loop, obviously !  :) If the standing end is at the upper left side of the picture, and the eye leg at the lower right side, and if we count the "crossing points" of the standing part with itself starting from the standing end, the "second" ( at the right side of the picture ) crossing point is the one that should be maintained at all costs - so, the returning eye leg has to secure that the two segments of the crossing knot that meet each other at this point remain in touch ( or very close ) to each other, and only then to secure itself, hiding in between his fathers pants ( the strong standing part s first curve ) and his mother s skirts ( the weaker returning eye leg s first curve ). So to make sure that the crossing knot will remain crossed at this "second" point, the working end needs to turn around the two segments that meet there. Following this strategy, you will tie all the crossing knot-based loops we have, and then some !
Title: Re: the pet loop
Post by: Dan_Lehman on June 11, 2013, 05:05:14 PM
   Notice two things :
   1. The second end ( at the right side of the picture ) of the first "small" bight
 ( the bight that is going to form the nipping loop ) goes "over" its first end
 ( at the left side of the picture ),

?!  I see not "bights" but "loops" --fitting the standard
definitions (and such terms as "nipping loop")--, so it would
help to so refer to them.

Secondly, given the orientation of ends in the finished-knot
image, the SPart is not what begins (and happens to end)
on the right, but on the left.

Quote
I have no doubt that this loop is much better than the Span loop ( ABoK#1049 )
 --the tail is secured/locked in between the first curves of the standing part AND the returning eye leg ),
 but, judging from past experience, I reckon that this would need 60, at least, years
 to be understood and appreciated by Ashley s devoted followers :).     

By Ashley's presentation, the function of the span loop is to
provide an attachment eye for a "span"; hence, the knot is best
if "TIB" (one might think of the butterfly, but maybe that's
not among the "this series" Ashley cites).  Your given eye knot
seems intended for a particular SPart loading and the other end
qua tail (unloaded).

Note that the start of the span loop is consistent with making
one of the bowline in the bights --one needs to make the
"back flip" of the inserted bight (or loop, for other versions)
back around the knot to collar the SPart.

As for how many times some part is nipped, that is not even
a sure indication of value on its own of security of that part,
let alone an indication of the quality of the knot overall
--such things as ease of tying/untying, economy of material,
and so on.   If both knots are secure (loose, loaded), then
counting number of points of binding is rather academic.


But, in any case, the showing of inserting bights/loops within
others is a good opening of the mind to methods for forming
knots.  I have found one (which is much MUCH better
than these!) that works decently qua mid-line eye knot,
and I think should prove reasonably sound in other regards,
but which I cannot assuredly tie with the ends (i.e., by
non-TIB method), and which requires, for that, some careful
formation and then holding-in-place while the knot is
completed by reeving the tail through it.


--dl*
====
Title: Re: the pet loop
Post by: X1 on June 11, 2013, 05:29:23 PM
?!  I see not "bights" but "loops" --fitting the standard definitions (and such terms as "nipping loop")--, so it would help to so refer to them.
OK - but a nipping loop which has not yet been penetrated by something that is going to be nipped, is still a bight, is nt it ?  :)

   Your given eye knot seems intended for a particular SPart loading and the other end qua tail (unloaded).

  Indeed - but it works fine as a midline loop as well. I have to admit that I was seduced by this fine bowline-like (post-eye-tiable) eyeknot that is also a TIB knot! As I had mentioned, I prefer to tie it as TIB, even at the end of the line ! So, what is wrong with a double edged sword ?  :)

   As for how many times some part is nipped, that is not even a sure indication of value on its own of security of that part, let alone an indication of the quality of the knot overall

   You missed this point ( Ruby has understood it much better ). It is not about "how many times', it is about "where" ( in between the two stronger opposing curves of the knot s nub ), and "how" ( at right angles ). The where and the how the tail is secured in this eyeknot, is not only an "indication", but almost a proof !  :)

    I have found one (which is much MUCH better than these!) that works decently qua mid-line eye knot,
and I think should prove reasonably sound in other regards, but which I cannot assuredly tie with the ends (i.e., by non-TIB method

  Will you e-mail a picture of it to us, the next century or so ?  :) Perhaps at that time it would be TOO late for me to comment on it... :)
Title: Re: the pet loop
Post by: X1 on June 11, 2013, 05:56:53 PM
   Notice two things :
   1. The second end ( at the right side of the picture ) of the first "small" bight ( the bight that is going to form the nipping loop ) goes "over" its first end ( at the left side of the picture ),

...given the orientation of ends in the finished-knot image, the SPart is not what begins (and happens to end) on the right, but on the left.

   Read this ( quite complicated, I admit it...) phrase one more time... ( it is correct). I am talking about the relative positions ( "over" / "under" ) of the "first" and "second" ends / limbs of the "first" bight ( the one "above" the other, at the picture , which will become part of the rim of the crossing knot s nipping structure ), and the corresponding ends / limbs of the "last" bight ( the one "below" the other, at the picture, which will become the "collar" around the two eye legs ). The Standing end of the finished eyeknot is at the left side of the picture ( it is identical with the "first" end / limb of the "first" bight ). Perhaps I should nt have shown it at the "vertical" orientation in the last picture... but I always want to show that the main purpose of this eyeknot is to be a decent bowline-like post-eye-tiable loop that happens to be TIB as well, not a mid-line eyeknot ( that can be loaded both ways ). I think that if I were to tie a mid-line loop only, I would have tied a Butterfly loop. I am always interested in PET eyeknots, but I was surprized that a fine one, as this loop is, was also a TIB knot  ( it was a bonus ! ) - and I got stuck with it ! Now, I prefer to tie it as TIB, always !
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: Ruby on June 12, 2013, 03:58:33 AM
Crossing knot ...

these knots look like zepplin bend

maybe zepplin bend is formed by two interlocked crossing knot? (unlike  some interlocked overhand)
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on June 12, 2013, 09:54:46 AM
these knots look like zepplin bend
maybe the Zeppelin bend is formed by two interlocked crossing knot? (unlike  some interlocked overhand)

  The Zeppelin bend is completely different from most bends we know, that is true - it is a rope made hinge, with the tails playing the role of the pivot of this hinge. The main bights, the first curves of the standing parts, are not "hooked" on each other : they remain parallel to each other, and they are connected only indirectly, by the pair of their tails that penetrate the two parallel "rings" and are able to withstand the shear forces acting on them.
   However, each link is still topologically equivalent to the overhand knot, while a crossing knot is topologically equivalent to the unknot : that is why the crossing-knot based loops are post-eye-tiable eyeknots. When you release any knotted structure that involves the continuation of the returning eye leg, there remains nothing knotted on the standing part. This is a sine qua non of a mooring knot, as the bowline : the very moment one removes the returning eye leg from a bowline-like loop tied around a bollard or within a ring on the dock, the mooring line is "clean", unknotted - so it can be pulled on board without the danger of being caught somewhere, during the dangerous moments the ship leaves the dock. The last thing a sailor on board of a ship that leaves the dock wishes, is to use the mooring line to "fish" a knot tied on its free end !  :)
  Moreover, you should look at how a particular "shape" of a rope segment is loaded, that is, you should try to "see" the flow of the tensile forces running through it, before you decide if it is "similar" or not to another... At a crossing knot, both ends are loaded, at each Zeppelin bend s link the second end, the tail, is unloaded. 
Title: Re: the pet loop
Post by: X1 on June 28, 2013, 02:02:28 PM
 
   By Ashley's presentation, the function of the span loop is to provide an attachment eye for a "span"; hence, the knot is best if "TIB" (one might think of the butterfly, but maybe that's not among the "this series" Ashley cites).  Your given eye knot seems intended for a particular SPart loading and the other end
qua tail (unloaded).
By Ashley's presentation, the function of the span loop is to provide an attachment eye for a "span"; hence, the knot is best if "TIB" (one might think of the butterfly, but maybe that's not among the "this series" Ashley cites).  Your given eye knot seems intended for a particular SPart loading and the other end qua tail (unloaded).
   It is impossible to show the pet Loop in all possible orientations and loadings of its four limbs - and I do not claim, of course, that I have examined all of them ! However, there is one advantage of this knot which, in comparison to the Span Loop, is almost self-evident  : In the case when both eyeknots are loaded mainly from their two standing ends ( that is, when they are tied-in-the-bight on a tensioned main line and the loading of the eyeknot from the two legs of the eye is much lighter than the loading from the two ends ), the pet Loop seems stronger than the Span Loop. The pet Loop s first standing curves, being "hooked" to each other, do not suffer as much as the one end of the Span Loop which makes the collar- like sharp U turn around the other - and this is not depending upon the specific orientation of the two Standing ends, or the amount of tensile forces induced into the eyeknot by a more or less loaded eye.  See the attached pictures - I am talking about the end coming from the left side of the picture. Therefore, I have a reasonable argument to support my claim that, even during such a "spanned" configuration, where those TIB / midline eyeknots are tied on a more or less tensioned from both ends main line in order to provide a purchase, the pet Loop would be stronger than the Span Loop.
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: X1 on June 28, 2013, 02:17:14 PM
  In the previous post, I have used, on purpose, an image of the pet Loop where the left part looks somehow "similar" to the left part of the Span Loop - so one can easily distinguish the difference of the way the Standing Parts first curves are "hooked" inside the two eyeknots.  A more "natural" dressing and final stage of the pet Loop is shown at the attached pictures of the present post. The eyeknot ( meaning, the "nub" of the loop ) is more compact, and more aligned with axis of loading of the eye. One can see that there in no sharp, collar-like U-turn like the one that exists at the Span Loop.
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: xarax on August 21, 2013, 03:06:48 PM
   Notice that the pet TIB B can be tied in a more secure form, if the path of the tail ( in relation to the standing part s and the eye leg s "hooks"/ first curves ) is similar to the path followed in pet TIB A ( i.e., if the tail is "locked" securely in between them ).

   Here is another way one can tie the pet TIB BB eye-knot. Although it looks more secure, as said above, its security depends upon the stiffness of the material - tied on a soft, very flexible rope, the Tail that works as a toggle, can bend and slip outside the knot s nub.
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: Luca on September 01, 2013, 11:00:45 PM
Hi,

If one has the patience to learn the Kung Fu method for the common Bowline by Alan Lee mentioned here http://igkt.net/sm/index.php?topic=4476.msg29856#msg29856 (look at the video!),it can take advantage of a variant of this method to run fast even the PET TIB (A) loop.Below the differences between the Kung Fu method for the common Bowline and the one for the Pet loop(in the "KungFuPetLoop2" diagram the two movements are numbered in order of execution,because the first have to be performed necessarily before the second).
                         
                                                                                              Bye!



(http://)



(http://)
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: Luca on November 18, 2013, 01:00:26 AM
Hi,

Below the simplest representation I've found to describe how to realize the Pet loop, perhaps it is also the most inaccurate way to represent it, but the knot at the end is all there: with a little practice, one can realize that it is really easy and fast to build like the Span loop #1049!

                                                                                                           Bye!
(http://)
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: xarax on November 18, 2013, 01:50:03 AM
it is really easy... to build like the Span loop #1049!
   No, it is easier to remember how to tie, and to tie, than the Span loop ! - because you start from a symmetric configuration (see the first picture), and then you half-reeve the right bight ( with your right hand ) from the back to the front, ( see the second picture), and then you full-reeve the central bight, again from the back to the front ! Once you have applied this method a few times, you can not forget it !  :)
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: Festy on November 18, 2013, 09:05:45 PM
it is really easy... to build like the Span loop #1049!
   No, it is easier to remember how to tie, and to tie, than the Span loop ! - because you start from a symmetric configuration (see the first picture), and then you half-reeve the right bight ( with your right hand ) from the back to the front, ( see the second picture), and then you full-reeve the central bight, again from the back to the front ! Once you have applied this method a few times, you can not forget it !  :)

X, is it a directional loop knot?
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: xarax on November 18, 2013, 09:40:23 PM
   If you ask if it can be loaded from the one or the other end, or from both ends at the same time, then yes, it can - just as the Span loop. However, as a crossing-knot loop, it behaves better if it is loaded by the particular end shown in the pictures. See how securely the Tail end is nipped in between the two opposing loaded bights, the first curve of the Standing part and the first curve of the returning eye leg. Also, it is a PET loop only if it is loaded from this particular end, because the one, the crossing-knot bearing link, is TIB, while the other, the overhand knot bearing link, is not.
   As mentioned in another thread, no TIB loop can be 100% symmetric ( yes, this is always true, and it happens even in the case of the seemingly symmetric Alpine Butterfly loop ...). So, for any such loop, loading from the one end would always be different - better or worse - than loading from the other.
   I find it very interesting, and very convenient, that the pet loop does not need any transformation / transfiguration in order to be used as a end-of-line loop or as a midline loop. As a "span" midline loop, in particular, it settles in a less asymmetric form than the Span loop, where the bulk of the knot s nub and the eye are not aligned vertically (1)(2).

1. http://igkt.net/sm/index.php?topic=4354.msg28285#msg28285 (http://igkt.net/sm/index.php?topic=4354.msg28285#msg28285)
2. http://igkt.net/sm/index.php?topic=4354.msg28286#msg28286 (http://igkt.net/sm/index.php?topic=4354.msg28286#msg28286)
Title: Re: Two pairs of pet TIB twin eyeknots
Post by: Festy on November 18, 2013, 09:47:49 PM
Thank you X,

F