Author Topic: Hugo bend (a descendant/heir of the Zeppelin bend)  (Read 32573 times)

X1

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Hugo bend (a descendant/heir of the Zeppelin bend)
« on: October 25, 2012, 02:01:43 PM »
   The only thing that is not convenient in the G Zeppelin bend, is that it is made by two overhand knots. So, it cannot serve as a base for a bowline-like end-of-line loop, without significant changes, which reduce its simplicity in the utilization and loading of the material as well as its beauty and ease of inspection, offered by this simplicity.
   { I am always interested in bowline-like end-of-line loop knots, because they are more convenient in their use, as they can be untied in one step - leaving no knotted trace on the standing part, that should be untied in another, second step. When used as mooring knots, bowlines have the great advantage that they disappear as knotted bulks of rope material from the mooring line the same moment the tail is released from the standing part and the loop is released from its anchor point on the dock. A rope with a knot tied on it, while the ship has lost its anchor security and has started moving, is a dangerous thing. The loose knotted rope can be re-attached somewhere, and this can cause severe problems during this sensitive phase.}
   I thought that if we transform the topologically-equivalent-to-the-overhand-knot links, to topologically-equivalent-to-the-unknot, this might lead somewhere. So, I untucked the standing ends of a G Zeppelin bend, twisted the collars to one particular direction, and then retucked them again - through both collars this time. The overhand knot disappeared, as it was planned, and I was left with the bend shown at the first two attached pictures. I do not remember to have seen it somewhere, but my sources are limited. I am also almost sure I myself have not tied it, but there are hundreds of bends out there, so I might have seen it and then forgoten it.
   Why this bend is related to the G Zeppelin bend ? Not because it is derived from it, of course. Because its mechanism is similar with the hinge mechanism of the original G Zeppelin bend, where the two bights are not hooked the one into the other ( as it happens in all the other interlocked overhand knot bends), but they are interlinked through the intermediate pivot, made by the pair of tails. I believe that it is exactly this hinge mechanism (a mechanism based upon shear forces that act perpendicularly on the axes of pivots), which is responsible for the easiness of untying of those bends, even after heavy loading.
   I have not loaded this bend to the limits of the rope strength, and I would be glad if some member of the Forum would do this, and report his results to us here.
   A related bend, the "slipped overhand knots bend", based on a similar hinge mechanism, was presented  elsewhere (1) ( See the third attached picture). The Hugo bend is not very different, but I believe it is prettier - although, of course, it cannot be compared with its ancestor.
 
1.  http://igkt.net/sm/index.php?topic=3716.msg21527#msg21527
2.  http://en.wikipedia.org/wiki/Hugo_Eckener
« Last Edit: October 25, 2012, 02:03:35 PM by X1 »

X1

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Re: Hugo bend (a descendant/heir of the Zeppelin bend)
« Reply #1 on: October 25, 2012, 02:53:54 PM »
   Another dressing of the same bend is shown in the attached pictures. It may be argued that the tails are nipped in this dressing once again, relatively to the the simpler dressing of the bend shown at the previous post. However, the hinge mechanism that keeps the two bights interlinked together, works also as a very effective " lock" mechanism of the tails. So, I do not believe that the more complicated dressing presented here would be really necessary.

Dan_Lehman

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Re: Hugo bend (a descendant/heir of the Zeppelin bend)
« Reply #2 on: October 25, 2012, 03:59:05 PM »
The principal benefit of seeing these end-2-end knots
is that by comparison they make the TIB zeppelin
eye knot perfectly beautiful!!

Thank you for that (though it already looked okay, IMO).

 ::)

X1

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Re: Hugo bend (a descendant/heir of the Zeppelin bend)
« Reply #3 on: October 25, 2012, 05:01:15 PM »
   I have not presented this bend as a beautiful one !  :)
   You see, the children of good-looking parents are seldom prettier than them.
   Is your beloved TIB "daughter" an exception ?  :)

   
« Last Edit: October 25, 2012, 06:13:01 PM by X1 »

X1

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Re: Hugo bend (a descendant/heir of the Zeppelin bend)
« Reply #4 on: November 04, 2012, 01:56:56 PM »
   It may sound a little too abstract or general to some, but ALL bends ( end-to-end knots) belong to three, and three only, broad categories. *(1)
   The most important part of any bend is its Standing parts first curves. It is there where the loaded bend will make it or brake it. So, it is reasonable to classify bends according to the specific characteristics of those curves, and not of the rest of their two links entanglement.
   The first curve of each link of a bend can make a turn ( can bend ) around :
   1. The other link s straight part of the standing part - the straight continuation of the standing end.
   2. The other link s first curve of the standing part.
   3. The other link s tail.

   In that sense, the Zeppelin bend, along with the Hugo bend presented in this thread, are members of a very small class of bends, which I use to call "rope-made hinges". The first curve of each link does not turn around the straight segments of the other link s standing part, and it is not hooked with the other link s first curve : it turns around a "pivot", made by the two tails. The "slipped overhand knots bend" (2) is another - and I do not know if even the "Oval bend" (2), belongs to this class or not. ( I do not mention the simplest bend possible, the Symmetric Sheet bend, which, together with the Whatknot, belong to a very special class ).

    So, I see another "benefit"  :) of the Hugo bend, which other people do not : it illustrates the almost unique character of its ancestor, the Zeppelin bend, as a rope-made hinge - the mechanism which is the main reason for its superb knotting qualities.

*(1) We are interested on the class of symmetric bends here, which includes the great majority of bends. - i.e. the bends where each link s shape is / can be considered as, a symmetric transformation of the other s.
2. http://igkt.net/sm/index.php?topic=3716.msg21527#msg21527
3. http://igkt.net/sm/index.php?topic=3741.0

   
« Last Edit: November 04, 2012, 11:11:57 PM by X1 »

X1

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Re: Hugo bend (a descendant/heir of the Zeppelin bend)
« Reply #5 on: November 05, 2012, 07:28:16 PM »
   Pictures of the Hugo bend - a crossing-knot, bowline-like (PET) end-of line loop based upon the Hugo bend. We see that the initial high symmety of the Hugo bend is disrorted a little bid, because the loop is loaded with the un-symmetric distribution of the whole load of any end-of-line single loop ( 100% at the standing end, 50% at each leg of the bight). However, the Hugo loop is very secure, and very easily untied, even after heavy loading - as all the Zeppelin-like and most of the bowline-like knots do.
« Last Edit: November 05, 2012, 07:29:18 PM by X1 »

SS369

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Re: Hugo bend (a descendant/heir of the Zeppelin bend)
« Reply #6 on: November 06, 2012, 01:23:31 AM »
The Hugo Bend B is my pick so far. Here is a 400 lbs. loaded example using 6mm BW accessory cord.
I had no problem untying it whatsoever.
I have tried it using 5mm Dyneema and the stiffness of the cord makes tying and dressing more challenging, but it performs nicely at the load levels I can achieve.

S
« Last Edit: November 06, 2012, 01:24:39 AM by SS369 »

X1

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Re: Hugo bend (a descendant/heir of the Zeppelin bend)
« Reply #7 on: November 06, 2012, 02:24:47 AM »
   Thank you SS369,

   At the unloaded bend, we can see the wide first curves of the standing parts - something that, along with the fact that the two links are topologically equivalent to the unknot ( i.e. they are not overhand knots, or fig.8 knots, or something even more complex ), distinguishes this bend from the parent Zeppelin bend. I wonder if the radii of those curved segments will remain relatively large in a heavy loaded knot as well - which would mean that this bend might be stronger than the Zeppelin bend. Your picture is not very informative about this, I am afraid. We should had tied the Zeppelin bend and the Hugo bend(s) on the same material, and had submited them to the same heavy loading, so we could compare them.
   If the rope is very stiff, I guess that the tails / "pivots" of the simpler Hugo bend can withstand the local strong shear forces, and they will not slip, although they are nipped at one only point.  Of course, i Io not know if that will be the case with Spectra/Dyneema ropes - I had never tested any knots tied on those materials...
   Now you made the first step, could you, please, try the Hugo lbowline-like crossing knot loop using the same materials, and see how it is behaving ?

SS369

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Re: Hugo bend (a descendant/heir of the Zeppelin bend)
« Reply #8 on: November 06, 2012, 02:47:18 AM »
    I wonder if the radii of those curved segments will remain relatively large in a heavy loaded knot as well - which would mean that this bend might be stronger than the Zeppelin bend. Your picture is not very informative about this, I am afraid.

   Now you made the first step, could you, please, try the Hugo lbowline-like crossing knot loop using the same materials, and see how it is behaving ?

Please let me know how I can make my picture(s) more informative.

I will be trying the loop version soon.

SS

X1

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Re: Hugo bend (a descendant/heir of the Zeppelin bend)
« Reply #9 on: November 06, 2012, 03:23:09 AM »
Please let me know how I can make my picture(s) more informative.

   You could possibly offer your readers a pair of X-vision glasses, for example...because those standing part first curves are deeply buried in the knot, and they can not be seen.  :)
( And using close-up pictures, of short-tailed knots, tied on cordes of two different colours, would also help...) :)
   I like the symmetric bends turned-into-loops, when the loop is at least as good as the bend ! On the contrary, I feel really sad, when a fine ( superb...) beautiful bend is turned onto a mediocre, ugly loop - as it happens with THE Zeppelin knot, the Zeppelin bend, and all those pseudo-Zeppelin loops ( some of them not even bowline-like (PET). I feel that knots should be respected - their individual character, mechanism, silhouette, should be approximated with attention to the details, and care.
    Have a look at the Teedledee bowline (1). It is on the same level with the Tweedledee bend (M.A24), so the existense of the loop does not offend the parent knot, the bend. The same can be said, - although some might argue differently, and they might be right - for the Double Harness bowline (2).

   1. http://igkt.net/sm/index.php?topic=3989.0
   2. http://igkt.net/sm/index.php?topic=3984.0
« Last Edit: November 06, 2012, 03:32:40 AM by X1 »

kd8eeh

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Re: Hugo bend (a descendant/heir of the Zeppelin bend)
« Reply #10 on: November 06, 2012, 04:24:12 AM »
looking at this picture, i noticed some resemblence to a jar sling knot, only with the overhands offset a little.  it's probably nothing, but if i tie a jar sling knot as a bend, i get this.  is there anything curious about this relationship?  also, i tried to shift the overhands one more turn over and make the closest thing i can, and i was left with another hugo bend, but loaded on the tails, with the main strands being the new tails. 

SS369

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Re: Hugo bend (a descendant/heir of the Zeppelin bend)
« Reply #11 on: November 06, 2012, 05:12:22 AM »
Please let me know how I can make my picture(s) more informative.

   You could possibly offer your readers a pair of X-vision glasses, for example...because those standing part first curves are deeply buried in the knot, and they can not be seen.  :)
( And using close-up pictures, of short-tailed knots, tied on cordes of two different colours, would also help...) :)
   

But you did such a good job of the loose knot I felt it would be redundant. ;-)
But you are correct in that my photo was not up to snuff. Just had the semi-smart phone available at the time.
Oh and wouldn't xray glasses come in handy!

Point was that this knot performed well and my photo and report showed the compactness when tight, was easy to untie and was indeed tied, not just viewed.

SS

X1

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Re: Hugo bend (a descendant/heir of the Zeppelin bend)
« Reply #12 on: November 06, 2012, 10:54:00 AM »
i noticed some resemblance to a jar sling knot. 
if I tie a jar sling knot as a bend, i get this. is there anything curious about this relationship?

  What you show is Mike s bend (1), and you have noticed its relationship with the jug sling, as described by Mike himself at (2). To me, yes, it was curious / unexpected ! Mike s bend is a very interesting bend, with very wide first curves - only its initial form is a little unstable : the two links can slide within each other, and the tightened knot can lose the perfectly symmetric geometry of the loose knot.
   Perhaps I have to say something at this point : when I declared  :) that all bends belong to three, and three only, classes at Reply#4 (3), I knew that there was a class of bends which can not be included in any of those classes in a strightforward manner, but I had left the issue for later. It is the Axis class of bends ( Axis knot ( M. A22), Mike s bend, Pretzel-to-Pretzel bend), shown at the attached pictures. I believe that those bends belong more to the first class ( the first curve of each link turns around the other link s straight part of the standing part - the straight continuation of the standing end), than to the third ( the first curve of each link turns around the other link s tail), although this is not so clear as in other bends, indeed.
   At the Hugo bend as well as at the Zeppelin bend ( and, possibly, at the Oval bend), the first curves do not turn around the straight segments of the standing parts, but around the tails, and around the tails only. This is the difference I had pointed out, which distinguishes those bends from the members of the Axis class of bends.
   
1.  http://igkt.net/sm/index.php?topic=3585
2.  http://igkt.net/sm/index.php?topic=4089.msg24520#msg24520
3.  http://igkt.net/sm/index.php?topic=4090.msg24704#msg24704
« Last Edit: November 06, 2012, 11:27:01 AM by X1 »

X1

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Re: Hugo bend (a descendant/heir of the Zeppelin bend)
« Reply #13 on: November 06, 2012, 11:06:02 AM »
my photo and report showed the compactness when tight

  Yes, indeed, and I thank you for this. It is nice to know that a knot one presents in this Forum is going to be tied by at least one other person !  :)
  Is this a good thing ? ( Not that ! :)). I mean, is it good for the Hugo bend to become so compact when tight ? Because one would argue that, in this compact, form, in this small overall volume, the previously noticed wide curves, which were supposed to be one of the two advantages of this bend compared to the original parent Zeppelin bend, are no more... That can be said also for Mike s bend ( read the previous post), which also shows a tendancy to lose its very wide turns when tightened and compactified. If we will not going to have any wide curves, why are we going to tie those bends in the first place, and not something else, much simpler ?

X1

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Walking Beauty (M. A16 - ABoK#1063)
« Reply #14 on: November 08, 2012, 02:21:11 PM »
   One other bend where the first curve of the one link turns around a tail, and it is not hooked to the first curve of the other link, is the Walking Beauty ( M. A16 - ABoK#1063)( See the attached picture ).
   However, on closer inspection, one can see that this bend is, in fact, a variation of the Hunter s bend, not of the Zeppelin bend. The two first curves are embracing each other, they are not parallel to each other - although they are not "hooked" directly to each other, in the strict sense of the word. We can not characterize this bend as a  rope-made hinge" , but it is true that it is untied very easily, due to this configuration of the standing parts first curves - just as it happens with the other bends discussed in this thread.
   I do not like the Walking Beauty - not, of course, because it is a beauty, but because it walks... :). The two links can not form a stable, compact whole, without being pretensioned quite forcefully. So, when unloaded, this bend remains in a loose, unstable form most of the time, especially if it is tied on stiff material.
   Trying to improve this, I un-tucked the tails, and re-tucked them again through the same bights they were going through in the parent Walking Beauty - but at the other side of the other segments that also penetrate the same bights. That is, a simple change that does not alter the locking mechanism of the bend at all - the tails penetrate the same nipping bights, following the same orientations as before, and they remain crossed with the same other segments into the same positions.
   As expected, what emerged was a Hunter s bend variation, that I had labelled as "top side twist", presented at (1). This is a proof that the Walking Beauty is not related to the Zeppelin bend, but to the Hunter s bend - and, as the Hunter s bend, it is not a " rope-made hinge" .

1.   http://igkt.net/sm/index.php?topic=3204.msg19163#msg19163