Author Topic: Simple Helical loop, and ABoK#1032  (Read 5365 times)

xarax

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Simple Helical loop, and ABoK#1032
« on: May 05, 2015, 01:51:51 AM »
   Five months ago, working on an original idea by SS369, I had tied an interesting simple adjustable Helical loop, shown in (1), and at the attached picture. Personally, I happen to like this simple yet amazingly secure adjustable loop so much, that I have included it in my personal collection of "new" knots, in place of the Buntline extinguisher, or Constrictor hitch, - which, as its name implies, had replaced the Buntline hitch itself a few years earlier.
   After Moebius convinced us about his clear-cut idea, that a TIB loop has better be EEL as well ( Either End Loadable ) - or, in other words, it would be really pity if a tiable in-the-bight loop can not be loaded by either end -, the EEL condition became almost an obsession for me, and whenever I have a few moments, I tie a loop I know and try to see how it will behave if it is loaded by its "other" end, by its ex-Tail, EVEN if it is not TIB:)  :)
   I have seen many interesting things, which I will present in the Forum when I will have more time. However, what is most important, is that all those trials proved, just another time, what I keep telling years now, in dozens of posts, and hundreds of "line fillings" by "keystroking" : that there are many cases where topologically identical knots are geometrically very different, so they are different structures, different knot mechanisms, "work" differently, behave differently, in short, they are altogether different knots ! (2)
   I am saying that because, recently, I had presented a "new" loop, the Plait loop, which is topologically identical to the well-known ( and sooo ugly ) Farmer s loop ( i.e., just as the straight, unknotted line is topologically identical to the slipped overhand knot ), yet it is a different knot, because its geometry, and so the way it "works', is very different from the geometry of the Farmer s loop - and to say that the one is "the origin" of the other, or that the one is "one form" of the other, is pure nonsense . I tend to think that what one believes about this matter, in the "community" of knot tyers, is what really separates the men from the boys and girls !  :) :)
   So, the reader is advised to tie this simple adjustable loop, and load it by its "other" end - that is, do not load it as a Helical loop any more. ( A Helical loop is a eyeknot where the "nipping structure" tied on the Standing Part before the eye ( which, on the bowline, for example, is a single "closed" nipping loop ) is not a "closed" but an "open" knot, a helical coil. (3))
   The reader may be surprized with the outcome, as I was : the "either end loaded" Simple adjustable Helical loop, is transformed into the well-known, most beautiful Chinese cross loop / Friendship loop (  ABoK#808, #809, #1032 ,#1060 ) (4) ! Now, if one who has eyes, and just a minimum amount of brain to support them, really believes that any of those two knots is "a form" of the other, or it is "the origin" of the other, or that they "work" the same way, and they are the same knot, should better go back to the start, and start again !   :) :)
   
   However, here comes the real, important for me question : Which one do I prefer ? For the time being, I will leave my heart wide open to both... :). Time will tell, I guess, because that is the role it plays in the Universe : It first makes the few things many, and then the many few, again... :)

   http://en.wikipedia.org/wiki/Friendship_knot
   "This is one of the eleven basic knots of traditional Chinese knotting, a craft which began in the Tang and Song Dynasty (960-1279 AD) in China. The Chinese and Japanese names for this knot are based on the shape of the ideogram for the number ten, which is in the shape of a cross. The Ashley Book of Knots, first published in 1944, says: "A decorative Chinese Loop. This is commonly employed as a Lanyard Knot. It is handsome and secure." In recent years, it has become popular with members of the Scout and Guide movements for tying their neckerchiefs instead of using a woggle."
   http://chineseknotting.org/cross/   

1. http://igkt.net/sm/index.php?topic=4965.msg33791#msg33791
2. http://igkt.net/sm/index.php?topic=4201.0
3. http://igkt.net/sm/index.php?topic=4949
4. http://igkt.net/sm/index.php?topic=4965.msg33816#msg33816
« Last Edit: May 06, 2015, 08:26:07 PM by xarax »
This is not a knot.

agent_smith

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Re: Simple Helical loop, and ABoK#1032
« Reply #1 on: May 05, 2015, 01:56:33 PM »
This might be a nice knot to compare to the Bowline (#1010) - to show that although it in some small way resembles part of a bowline - but that it isn't on account of the lack of a nipping turn to hold and compress a bight. Nice knot though... interesting comments about 'bi-axial loading' profile (EEL).

xarax

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Re: Simple Helical loop, and ABoK#1032
« Reply #2 on: May 05, 2015, 02:14:57 PM »
   Thank you, agent smith,
   A great advantage of the Helical loops is that, depending on the application, the environmental conditions, the required level of safety, and the material in hand, you can always just add one more turn to the helical coil.
   Take a look at the similar, slightly more complex, Helical loop based on a Constrictor-like core, with one and two helical turns, shown in the attached pictures. The symmetry of the Constrictor make the knot very easy to inspect, and its tightness make it very secure.   
   Another adjustable Helical loop ( "adjustable" at least in its 1-turn variation ), which it TIB, is shown in the third attached picture.
« Last Edit: May 09, 2015, 01:01:49 PM by xarax »
This is not a knot.

Dan_Lehman

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Re: Simple Helical loop, and ABoK#1032
« Reply #3 on: May 10, 2015, 07:47:03 AM »
This might be a nice knot to compare to the Bowline (#1010) - to show that although it in some small way resembles part of a bowline - but that it isn't on account of the lack of a nipping turn to hold and compress a bight. Nice knot though... interesting comments about 'bi-axial loading' profile (EEL).
Several decades ago, when I was fiddling such helical
eye knots --keen to have a "gradual curvature of the
S.Part", and even no U-turn(!)--, I got one tested, in
1/4" 3-strand nylon rope.  It held to rupture, apparently
w/o much or any slippage (YMMV with setting, etc.).
But I remain afraid of the structure vs. slippage and
especially it's challenge to setting jiust so (i.e., with
sufficient helical twist to bind and hold, but not so much
to defeat the point of gradual curvature --though one
can point to having more turns in the helix so as to
enable the initially loaded ones to be broad/mild.

The double bowline's turns can be re-oriented into
a helix by pushing the one nearer the collar through the
other to then open nearer the eye, and so the S.Part
will curve around & around to it.  I had this knot tested
too.

.:. The eyeknots were tied at both ends of a specimen
(so I'd have a survivor), and the two above were nearly
identical in strength (roughly 68% of presumed tensile
--presumption based on eye splice = 95% (I submitted
an eye-spliced specimen).


--dl*
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xarax

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Re: Simple Helical loop, and ABoK#1032
« Reply #4 on: May 10, 2015, 01:42:29 PM »
   The eyeknots that I have seen in pictures you had published, are NOT Helical loops:) They do have helical turns on the Standing Part, but the two ends of the helical coil are not the direct continuations of the Standing End and of the on-going eye leg... In the Helical Loops, it is the single and the double nipping loop of the common and the double bowline that have been replaced - and they were replaced with this "open" helix, a nipping structure where no point is in contact with any other point.(  In a "classic" bowline, there is one such point, the "crossing point", in the crossing-knot-based PET eyeknots, there are two. In a Helical loop, there is none ! )
   I know that one can not easily imagine that an "open" helical loop can be as secure as a "closed" loop - but it is ! Myself, I have discovered this during the discussions we had about a mid-span bend (1), when I was trying to figure out how one could attach a second line on a tensioned main line - and just after that, I had realized that the same most effective friction mechanism could be utilized in eyeknots. After I had tied and tried some of them, I had discovered that this idea, of the multiplication of the friction when the ""first curves"" are multiplied, was already widely known ( as one might had anticipated, of course ), and already applied in climbing and sailing. See the picture of a mooring shock absorber ( "snubber" ), based on such a coil. Here the purpose and function are slightly different, but the principle of an elongated "Standing Part", so its contact area with a compressible "core" is more extended, remains the same. I have seen similar mechanisms in climbing equipment.

   I have only recently realized that, if we have a complex enough, effective enough structure on the attached line, we do not need a closed nipping loop on the main line ! I was using a closed nipping structure till now, because I was driven by the similarity of a (TIB) mid line bend with the bowline - where the last  thing we want, is a deformed, opened, helical nipping loop ! 
   However, it turns out that any curve - even not so tight, closed curves as dfred and myself have been used till now - can, in fact, be utilizedo to prevent any slippage of the attached line alongside the main line.
   See the attached picture, where such a wide open, helical curve is able nevertheless to hold firmly in place the more complex, tight nipping structure of the attached line. I am sure we can find even simpler midline bends than the one shown here... and the interested reader is called to try his own hand.
   
1. http://igkt.net/sm/index.php?topic=3020.msg21688#msg21688
« Last Edit: May 10, 2015, 05:47:10 PM by xarax »
This is not a knot.

Dan_Lehman

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Re: Simple Helical loop, and ABoK#1032
« Reply #5 on: May 10, 2015, 06:24:20 PM »
   The eyeknots that I have seen in pictures you had published, are NOT Helical loops !
Nor are the ones in many other places.
But what does that have to do with anything?

--dl*
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xarax

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Re: Simple Helical loop, and ABoK#1032
« Reply #6 on: May 10, 2015, 07:04:54 PM »
But what does that have to do with anything ?

Nothing.
I just wanted "to be sure" we are talking about the same class of knots - and not about the Lehman8 and some other "similar" eyeknots, which do have a helical coil on the Standing Part before or after the eye, but not ONLY a helical coil  !  :)

I enclose some pictures of "vertical spools", as Storrick (1) calls them, which are based on the same idea, I believe : Figure out how to make the line follow a longer path, but without changing its curvature along it.

1.   http://storrick.cnc.net/VerticalDevicesPage/Rappel/VSpools.html
« Last Edit: May 10, 2015, 11:50:11 PM by xarax »
This is not a knot.

xarax

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Re: Simple Helical loop, and ABoK#1032
« Reply #7 on: May 16, 2015, 02:52:18 AM »
   Starting from the Chinese Cross loop / ABoK#1032, and by elongating it the other way, we arrive at the well-known arthroscopic knot, the Dines knot, before its capsize (1)(2). ( See the attached pictures ).
   ( I had to wait a few years to "see" the relation between those three knots, but better late than never...  :) )

1.  http://igkt.net/sm/index.php?topic=3659.msg21161#msg21161
2.  http://igkt.net/sm/index.php?topic=4107.msg24631#msg24631
This is not a knot.