Author Topic: "Tackled" hitches - a new class of tight hitches.  (Read 8919 times)

xarax

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Re: "Tackled" hitches - a new class of tight hitches.
« Reply #15 on: August 17, 2015, 12:04:01 PM »
   Was nt the method shown in Reply#4 clear enough ? ( The pictures were not, since I had taken them in the middle of the night, without a flash, but I believe the lack of sharpness plays no role int his case )
   However, generally, I avoid the presentation of particular tying methods, because there is this dangerous infectious DESEASE in the knot tyers community, to confuse a knot with its tying method ! ! Many people seem to be interested not in the nutritional value of the foods / the value of the knots themselves, but only in their cooking RECIPES / their tying methods. Each and every knot can be tied with many different tying methods, and, most importantly, every knot tyer conceive the same knot differently than the others, and may prefer a different tying method, for complex reasons ( having to do with the way different minds "see" 3D shapes ) we can not understand.
   Moreover, I believe that people who do not tie knots by viewing pictures of them, either because they are too lazy to do that, or because they do not want to "lose" their valuable time ( and prefer, instead, to watch another TV rubbish, for example ), should better NOT tie knots ! They should better use fasteners, or other means to join their ropes, because when you tie a knot blindly, without understanding what you do, sooner or later you will make a mistake you may regret : knots are dangerous things, and falsely or improperly tied and dressed knots are even more so !
   I ALWAYS provide pictures of the knots I tie - I am never hiding behind a vague "verbal description", as you say, to "save" my time, as many others do in this Forum ! !
« Last Edit: August 17, 2015, 12:51:10 PM by xarax »
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Tex2

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Re: "Tackled" hitches - a new class of tight hitches.
« Reply #16 on: August 17, 2015, 12:45:22 PM »
As usual with hitches there's a risk that people see advantages and trucker's hitches that aren't there, usually by inappropriate geometrical comparison to a trucker's hitch, inappropriate because the geometrical comparison does not extend properly to the circle on which the hitch is tied especially as compared with any other simple hitch of the same number of wraps over which that advantage should be measured. 

I am not for a second saying these are not very good knots, and I do not dispute the qualities xarax mentions. I haven't tried them yet to see (actually I've tried something close enough to the simple one to have a very good guess)

Regarding the "simple" hitch.  The interlocked U turns pull two rope segments (in and out) against two rope segments.  That's an even advantage.  One can say in a sense I think that there is a slight bit of advantage where the rope turns radially outward at the overhand knot, but no more than for many other radially extending hitches where that turn pulls against the tail, like say a timber hitch (as opposed to hitches that like to extend tangentially, like a clove hitch).  I've talked about this kind of pseudo trucker's hitch like tail loops a couple of times before.  They can help to some significant extent with the surging and the use of hands. So the advantage of it is very similar to a two wrap timber hitch  ( ok, the timber loop end might fall apart, but anyway any decent two wrap hitch has twice the grab of a single wrap hitch and this is part of the illusion of the u-turns.  It's not that they don't help, but.. so would continuing around the SAME way. They might help in other ways though like locking and surging.) 

The butterfly thing is interesting in that it appears to leverage four segments (counting ingoing and outgoing) against two.  This is the kind of counting you need to see to have real mechanical advantage.  In this case though, it's not quite so doubled as it appears, because those 4 parts pulling are drawn from two separate ends going in the same direction.  You can pull on both at once in one direction with half of your stength distributed to each!  Again, this is not to say it's a bad knot.  In fact the fact that the tails come out the same way and that one will hold gains while the other is pulled, does mean that the hitch can be fed tension more easily from both of its ends instead of creating one limp end like many hitches, and this does produces a sort of 2x advantage of its own if you can alternate that tension and hold gains as xarax described.  That's a very different kind of "advantage" from a pulley system though.  I agree with xarax that there is nothing trucker's hitch about any of this.

To me, the main purpose of a tight hitch should ideally be to hold in gains from things pulling much harder than my arms, building ever increasing tightness to produce ever increasing resistance to slip along the pole.  Maybe I ask too much.  If I only need tightness that I can create in my hands not to resist things that might then pull harder, then a tight hitch and binder become only barely different ideas, the main issue being the ability to lock in gains enough for me to tie the binder off.  And if I must let it be tightened by the load that is stronger than my hands, then I'm not sure how useful alternating tightening is.   

There is clearly a place for this kind of knot though, indeed on hard smooth poles, where ANY small amount of give-back while tying off a binder  will be too much, or where eventual stretch from the load might loosen a binder on such a hard surface.  The best advantages of the butterfly tackle seem to be for human, spinal supported, levels of forces where it can be conveniently tightened in its best way.
« Last Edit: August 17, 2015, 12:57:45 PM by Tex2 »

xarax

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Re: "Tackled" hitches - a new class of tight hitches.
« Reply #17 on: August 17, 2015, 01:53:05 PM »
...the advantage of it is very similar to a two wrap timber hitch

  Indeed - and to any two-wrap hitch based on the Cow hitch, where the 4 legs of the two interlinked Us are almost parallel to each other - because, regarding mechanical advantages, angles matter ! THAT was the purpose of this series : segments at "right" angles - which here means : parallel segments.

  the illusion of the u-turns.

  There is no "illusion" of U wraps. There is a 2 : 1 mechanical advantage in a properly "tacked" two-wrap hitch, while there can be NO such advantage in ANY one-wrap hitch - simply because the Standing End of a one-wrap hitch can be not pulled tangentially to the surface of the pole. That means that the 4 legs of the two interlinked Us are not parallel during pulling / pre-tensioning ( the Standing End, while it is being pulled against the pole, makes a 90 degrees angle with the other three ), so a great part of the mechanical advantage evaporates.
   Now, one may argue : Why can we not pull the Standing End tangentially to the surface of the pole, i.e., in parallel with the other three legs converging in the same point ? The answer is simple - but it is better if one also gets the "feeling" of it, by actually tying and trying those tight hitches. Because, however tight a "tight hitch" would become ( at the end of the pre-tensioning ), at the beginning, when we start pulling the Standing End, it can not withstand a forced rotation, so it will simply re-adjust itself, it will rotate, and during the most critical stage of the pulling its Standing End would become perpendicular to the surface of the pole, and not tangential to it. Even if the hitch will not be rotated as a whole, its nub will, and this will deform it badly and destroy its locking abilities.
   
   
That's an even advantage.

  It is not - but I am afraid to get it you have to tie and try it first ! :)
  A hint : the segments of ropes work as "springs" : they can be elongated, they can accumulate and they can store tensile forces. This is something one loses when one analyses a block and tackle simple machine, made from ropes with, supposedly, fixed rope lengths. I have seen this effect in action : Hitches like those work much better when they are tied on nylon rope, which is more stretchy.

   
  In this case though, it's not quite so doubled as it appears, because those 4 parts pulling are drawn from two separate ends going in the same direction.

   Noope ! :) When you will tie and try it, you will see another thing that you miss : During the pulling of one end ( remember, you have to pull the ends alternately, so each one of them receives your whole strength ), only three ends are tensioned - the end returning to you becomes slack, because there is so much friction at the contact points of the three interlinked Us.
   So, you pull the one end of "your" U, the other end of this U gets lose, you have two more ends (  of the "other" U pointing towards you ) which assist you ( they never get loose ! ), and the opposite tip of the main U / loop coming towards you with half the speed you pull the one end of "your" U. This would had result in a mechanical advantage of 2:1 - IF you were not helped, during your effort, by the tension of the legs of the "other" U, which do not become loose. It may not be 4:1, because the other U may not support half of the load at all tomes, but it would be close. You have to see those four umbilical segments as four springs, three tensioned one and one non-tensioned.
   Anyway, the talk about mechanical advantages is pointless, and it hides more than it reveals - because of the important factors left unaccounted : the friction at the contact points of the interlinked Us, and the springy nature of the segments of ropes. The important thing is to "see" how those hitches exploit fully the mechanical advantage of the Cow hitch, and are self-locking at the same time.
   In short, there is no hitch that even comes close to what a tackled two-wrap tight hitch can do. The Butterfly Tackled hitch I had presented made the pole scream, literally, like no other hitch I had ever tied. Moreover, it opens up in a fraction of a second, just by pushing the one bight of its nub over the other, and loosening the "lock".
« Last Edit: August 17, 2015, 01:58:49 PM by xarax »
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xarax

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Re: "Tackled" hitches - a new class of tight hitches.
« Reply #18 on: August 17, 2015, 02:06:52 PM »
   In general, we can not speak about a knot if we have not tied it - and by "tied it", I mean correctly, and a dozen, at least, times ! By just "seeing" the images of a knot one can understand how he can tie it, and get a rough idea about its behaviour, if it is related to something he has already tied in the past. However, when one sees an altogether new knot, like the ones shown in this series, he should not jump into conclusions prematurely.
  I had tied dozens of two-wrap hitches, and I had though I knew how they worked - until there was this bolt out of the blue, the ingenious Alaskan hitch, tied by SquareBanksAlaska, which put me out off my illusion. And, just lhe very last night, the Simplest Locked Cow hitch was also a reminder of the fact that a rope is a "simple" thing which has many degrees of freedom, so, a tangled rope (  = a knot ) can do many more, and different, things than we can ever imagine.
« Last Edit: August 17, 2015, 02:09:03 PM by xarax »
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Tex2

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Re: "Tackled" hitches - a new class of tight hitches.
« Reply #19 on: August 17, 2015, 02:12:31 PM »
I do not dispute  that local advantages are likely created by surging (friction loosening one place and tightening another).  These advantages can be important.  In the end they won't result in an overall average tension in the individual wraps  greater than the tension pulled on the ends, not once tension finally spreads around evenly (if it ever can), but they can help significantly to get it there. 

They aren't though generally what some casual onlooker sees when they think they see (or some suggestion makes them think they see) a trucker's hitch.

It's not actually hard to tie such true trucker's hitch mechanisms either of course, it's just probably not very practically valuable.

simultaneous posting.. I agree, I cannot speak about how the knot does work yet.  I only wanted to speak to a particular way that someone should not try to "see" that it does.
« Last Edit: August 17, 2015, 02:25:23 PM by Tex2 »

xarax

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Re: "Tackled" hitches - a new class of tight hitches.
« Reply #20 on: August 17, 2015, 02:24:41 PM »
In the end they won't result in an overall average tension in the individual wraps  greater than the tension pulled on the ends, not once tension finally spreads around evenly (if it ever can), but they can help significantly to get it there. 

   Believing in this myth as long as it will last, because, afterwards, when you will actually tie the knots and see ( or even measure ) how wrong you were, you will remember it ! : ) :)
   Start by comparing the Simplest hitch (1), with the Simplest Tackled hitch. I use to judge tightness by sound ( :) ), but you can use the other method I had proposed : their efficiency in an lengthwise pull.
   So, tie TWO Simplest ( un-tackled ) one-wrap hitches side by side, at the one end of a pole, and ONE Simplest Tackled hitch, at the other, and drag them simultaneously, towards the middle. Then, report your findings here. Only do not tell me that I had told you what you will tell us ! :)

1. http://igkt.net/sm/index.php?topic=5209.0
« Last Edit: August 17, 2015, 06:11:29 PM by xarax »
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xarax

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Re: "Tackled" hitches - a new class of tight hitches.
« Reply #21 on: August 17, 2015, 02:31:20 PM »
   And, when you will find any pair of one-wrap hitches, or any two-wrap hitch, which will be able to strangle as ferociously the poor pole as a Butterfly Tackled hitch, please, tell it to me, to throw this jungle of ropes around me out of the window : it will make all members of my family, and most members of the Forum, really happy  - and save my spinal cord at the same time ! :) :) :)
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xarax

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Re: "Tackled" hitches - a new class of tight hitches.
« Reply #22 on: August 17, 2015, 06:08:51 PM »
   Perhaps ( = PERHAPS ! :)), to tie the Butterfly Tackled hitch in-the-bight more easily / quickly, he/she should better start from the double loop shown at pict.#1.
   Then :
   1 : Flip the inner circle, and both ends leading to it, horizontally, to arrive at the shape shown at pict.#2
   2 : Flip the outer circle, and twist its legs, vertically, to arrive at the shape shown at pict.#3.
        Pay attention to ONE things :
        After stage #2, the crossing point of the legs of the outer circle ( after the flip / twist ), should now be at the OTHER side than the crossing point of the legs of the inner circle. ( In the attached picture#3, it is at the "front" side ). This way the ends of the hitch will become encircled by both sides, as they should.
    3 : Insert the left semicircle into the left inner loop, and the right semicircle into the right inner loop, to arrive at the shape shown at pict.#4.
    You are done - as shown in the not-so-clear picture of Reply#4.
   
    With repetition and experience, I believe one would find out the correct/optimum relation between the diameter of the initial double loop he should form and the diameter of the pole he wants to encircle.
   
    HOWEVER, and I want to underline it, there are MANY other, different ways one can tie this knot in-the-bight - I can not know, in advance, which will suit whom better. In the sequence I had shown, I had tried to retain a correspondence to the general mental image of this double loop with communicating bights, which one may consider as the "base" of this hitch. One may also start different initial basic shapes, and make different transformations. Contrary of how it may look at the first sight, this knot is NOT very convoluted : it has only a small number of tucks and twists, and that is why it can become so tightly wiven around the ends we want to immobilize and "lock". 
     
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xarax

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Re: "Tackled" hitches - a new class of tight hitches.
« Reply #23 on: August 17, 2015, 07:37:16 PM »
  hold in gains from things pulling much harder than my arms,
  If I only need tightness that I can create in my hands
  the butterfly tackle seem to be for human, spinal supported, levels of forces where it can be conveniently tightened in its best way.

  This is an old misconception people had, and I thought I had made it clear, and would not come back again to it...
   I am not talking about tensioning by hands for its own sake ! I am talking about pre-tensioning by hands, so the wraps will not become very elongated / oval / elliptically shaped if/when/while, later, there will be a tensioning by a load even much heavier than the force delivered by hands.
  In short : There are two kinds of hitches able to withstand a lengthwise pull : the hitches with cross-gathered wraps ( like the rat-tail stopper, and others shown by Ashley in his relevant chapter ), and the hitches with tightly woven wraps. If the wraps are not cross-gartered, or not tightly woven, they will slip, unless they are MANY - but we are talking about few-wrap hitches here : ANY hitch, even if it is not knotted, will hold ANY lengthwise pull, however strong, if it has a sufficiently big number of wraps...
   So, we want to tighten the wraps, just for this : to "pretension" the hitch, just as the civil engineers pre-tension their concrete. If we do this, the wraps will become less oblique, if/when/while this hitch will be loaded by a lengthwise pull, and so they will slip less easily, and also, during some moments of extreme loading, they will be translated along the pole less than the looser wraps of a less pre-tightened hitch.
« Last Edit: August 17, 2015, 07:38:15 PM by xarax »
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xarax

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Re: "Tackled" hitches - a new class of tight hitches.
« Reply #24 on: August 17, 2015, 08:28:22 PM »
  As I had mentioned in a previous post, in those two-wrap tackled hitches, when you pull the one end (= the one leg of the one U, linked to the tip of the main bight), both legs of the other U continue to pull the main bight "your" end is pulling : they remain tensioned at all times, they never become slack - so they "help" you, increasing the effective mechanical advantage, which, this way, comes closer to 4:1 than to 2:1, as one may had supposed. However, there is another possible advantage in this configuration, which I had also tried to exploit in the Butterfly Tackled hitch : the two "returning" legs of the two Us, are parallel, adjacent, and also squeezed upon each other by the two legs of the main bight, at their one end, and by the main nub of the hitch, at their other - AND, they are squeezed onto the surface of the pole at the same time. So, they "lock" each other, and the burden the nub of the hitch has to bear to immobilize any one of them, is distributed and lessened. Even if we UNTIE the one of the two interlinked loops which form the nub of the hitch, both adjacent ends of both Us remain tensioned, and in their former place. An additional advantage, regarding security, this twin configuration offers.
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xarax

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Re: "Tackled" hitches - a new class of tight hitches.
« Reply #25 on: August 18, 2015, 02:54:57 AM »
   The "full", more "fat"/bulky Butterfly Tackled hitch, shown in previous posts, can be tied even more easily, and in a conceptually simpler way, starting from a common Butterfly loop. To see how, do some "reverse engineering" : Tie the Tacled variation in-the-end, as you see it in the pictures, and then perform this tricky transformation : make the two Us, which turn around the tip of the main bight, be "swallowed" by the "mouth" of the nub, and get out of the other side all the way. You will be surprized : What you will get, after some redressing, will also be a Butterfly loop, with the ends going through its eye this time. Now, you can make a loop / collar encircle the ends of a loop, when they do not, or vice versa, by implementing the "haltering the collar" method. So, you can, in one move, have this "second" Butterfly loop, become a normal loop, without its ends going through its eye. Now, following the exact time-reversed sequence of the above described moves, you can go from one common Butterfly loop to its "Tackled" variation, following the steps, in reverse, you had followed to de-Tackle it ! :)
   ( I have not shown this method, because I want to promote the "slimmer" version, which can not be tied so easily using it - the nub is simpler, and one can easily lose the control of the many concurrent, in mid air, segments. )   
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Ruby

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Re: "Tackled" hitches - a new class of tight hitches.
« Reply #26 on: August 18, 2015, 12:58:12 PM »
the tricky transformation may introduce kinks.

In many such "retraced" knots, the one line may go "over" and then "under" the other, and thus we have the formation of unnecessary twists, "kinks" - which, besides being ugly, they may also be detrimental regarding the strength of the knot.  :D

xarax

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Re: "Tackled" hitches - a new class of tight hitches.
« Reply #27 on: August 18, 2015, 01:04:57 PM »
   As mentioned in Reply#22, we can either start from a double loop with communicating bights, or from a single end-of-line loop - but we should better start from TIB ones, in order to end with a TIB hitch. Starting from the ABoK#1021 loop ( which is nothing but two unlinked slipped overhand knots, joined by the pair of eyelegs of their common eye ), we end to a hitch with a nub a little simpler than we would, had we started from the Butterfly loop ( "simpler", just because the two overhand knots are now not interlinked ).
   However, although the nub is tight and stable, it is not deformed by the pulling if the ends against the pole, and it does not "walk" towards the tip of the main bight when the hitch is tensioned, it can not be untied very easily - in fact, it can be untied only with GREAT difficulty ! :)  Therefore, I suggest one better ties it near the very end of the pole, so, if he/she pretensions it as hard as I did ( by STEPPING ON the hanged pole - hanged by the one and then by the other end, alternately ), he/she would be able to force the hitch to slide just a little bit, reach the end of the pole, and so be released. 
« Last Edit: August 18, 2015, 01:05:45 PM by xarax »
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xarax

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Re: "Tackled" hitches - a new class of tight hitches.
« Reply #28 on: August 18, 2015, 01:09:10 PM »
the tricky transformation may introduce kinks.

  I know... It works better with some loops than with some others. I had mentioned it just as a way we can see how/why, starting from TIB loops, we end with TIB tackled hitches - but I do not believe that, as a tying method, it should be followed in all cases. 
« Last Edit: August 18, 2015, 01:09:50 PM by xarax »
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xarax

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Re: "Tackled" hitches - a new class of tight hitches.
« Reply #29 on: August 18, 2015, 02:23:06 PM »
   ABoK#1050 is interesting as a (TIB) Eskimo-like loop, but too lopsided for anything else. However, the nub of its Tackled version is OK, and it is not "walking" ( actually, because its asymmetry, it "walks" more while we pull the one end than while we pull the other, but after a while the whole nub reaches an equilibrium, and solidifies ). Trying to make it more visually appealing, I had sacrificed its TIB-ness ( just a little bit :)), and the result is shown in the attached pictures. Due to the fact that its nub is less convoluted, and less tight, the ends can be "pushed" through their "lock", and so the this hitch can be untied more easily than the one based on ABoK#1021.
« Last Edit: August 18, 2015, 02:24:28 PM by xarax »
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