Author Topic: The asymmetric Zeppelin Bend  (Read 12336 times)

[Inkanyezi] gone

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The asymmetric Zeppelin Bend
« on: December 02, 2010, 09:28:01 AM »
Any resourceful knotter knows that some knots can be doubled in order to get a firmer nip or more secure knot. The Sheet Bend is an excellent example of an asymmetric knot that often is doubled, particularly when there is a difference in size between the two ropes to bend.

The Zeppelin, however, is a symmetric knot, and it usually serves well without doubling, which only would make it more complicated to tie and also to untie.  But often the condition is such that doubling makes sense, just as with the Sheet Bend; particularly when there is a difference in rope size. When the ropes differ in size, the nip of the smaller rope becomes less secure in the symmetrically laid out bend, so when the joint is asymmetric, it calls for an asymmetric bend.

So, here it is; quite simple: The smaller rope has a doubled turn, thus filling better, while the larger rope has only one. In that way, the Zeppelin can serve as an asymmetric bend for bending a smaller rope to a larger.
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Transminator

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Re: The asymmetric Zeppelin Bend
« Reply #1 on: December 02, 2010, 09:59:13 AM »
Indeed

The same applies to the butterfly bend.
That is what I suggested in post 14 in this thread:
http://igkt.net/sm/index.php?topic=2072.0

2. Zeppelin or butterfly bend in which the thinner rope is tucked twice through the two eyes (the double sheet bend principle) before tightening

Greetings

[Inkanyezi] gone

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Re: The asymmetric Zeppelin Bend
« Reply #2 on: December 02, 2010, 10:35:21 AM »
The asymmetry is obvious, it is an asymmetric bend, joining ropes asymmetrically because of their asymmetric properties. It's asymmetry in the sense it is often used nowadays, with asymmetric connections of the computer to the internet for example. An asymmetric junction may call for an asymmetric solution. Thinking of it like that makes it more obvious, and just as Transminator points out, there are also other knots that might benefit from this simple transformation.

I did not intend it as a name of the knot, I still regard it as the Zeppelin, but the thin rope is doubled for the exact reason of asymmetry between the two lines to be joined. That is what led to the header of this thread; it is an asymmetric solution to an asymmetric problem. You might notice that "asymmetric" is not capitalised in the header.
« Last Edit: December 05, 2010, 05:29:02 PM by Inkanyezi »
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Transminator

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Re: The asymmetric Zeppelin Bend
« Reply #3 on: December 02, 2010, 01:49:21 PM »
mmh half-double to my mind equals 1!

I would suggest, for Inkanyezi's/my original solution: Zeppelin 1.5
If both ends are tucked twice, it would be a double zeppelin bend. The presented one is halfway between the simple and the double zeppelin.

The one presented by Xarax (interesting solution, as it gives an extra loop to attach something to) might be a "half zeppelin on the bight"
As a zeppelin bend made with two bights would be the zeppelin on the bight (which has two loops as ends, which gives even more options for attachments  :D )

I have used the zeppelin 1.5 many times for bending a thick and a thin rope together without problems. The double sheet bend failed miserably with the same ropes.
The butterfly 1.5 performed as well as the zeppelin 1.5 but both the zeppelin and butterfly bend in the simple form did not fail in my tests even with a ridiculous difference in rope thickness (1mm line and 14mm line e.g.) but it deformed heavily and the end result looked not very trustworthy. Therefore, in doubt, I used the zeppelin 1.5 or butterfly 1.5 instead. If all else fails, you can still go back to two interlinked standing loops.

SS369

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Re: The asymmetric Zeppelin Bend
« Reply #4 on: December 02, 2010, 03:53:45 PM »
"If both ends are tucked twice, it would be a double zeppelin bend."

I don't agree with this statement above. To me that describes a double tucked zeppelin bend.
This is my preferred bend and it pleases me aesthetically, adding the "decorative" to it at the same time as at least perceived security.

A double zeppelin bend would be either a retraced zeppelin or one tied with two opposing bights as the working ends.

I have tied the zeppelin bend many times using the smaller cord triple slipped. Essentially making a small coil at the smaller cords working end and snugging the larger cord around it.
Not a lifesaver but it works well.

Scott


knot4u

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Re: The asymmetric Zeppelin Bend
« Reply #5 on: December 02, 2010, 04:36:11 PM »
I view this concept mostly as an interesting theoretical discussion.  In practice, if I'm trying to join two ropes of different diameters and/or different materials, then I'm unlikely to use any of the standard favorite bends (and variations thereof).  There is a point at which the differences between two ropes is so great that most of the standard favorite bends (and variations thereof) will fail.  I don't care to guess where that point is in a real world situation.  So, I'm not going to get overly giddy about this idea.

Where there are differences in rope, it's time to take a breath and start thinking OUTSIDE the box.  A knot that is silly with equal ropes may suddenly become a better option with unequal ropes.
« Last Edit: December 02, 2010, 05:18:51 PM by knot4u »

SS369

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Re: The asymmetric Zeppelin Bend
« Reply #6 on: December 02, 2010, 05:25:20 PM »
"double tucked Zeppelin bend" <<< gets my vote. Makes sense to my poor mind.

SS

Dan_Lehman

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Re: The asymmetric Zeppelin Bend
« Reply #7 on: December 02, 2010, 06:38:59 PM »
Quote
A "Double Zeppelin bend" is the name of a bend were either the collars or the nipping loops are doubled.

Says who?

"double tucked Zeppelin bend" <<< gets my vote. Makes sense to my poor mind.

SS

The ambiguous denotation highlighted by XaraX suggests that SScott's conclusion
might be the better course.  I look to the Bowline & Sheet Bend (complementary
knots) and the use of "double" with them : I guess that the Sheet Bend is in the
same situation (w/less structure, slightly) as the R.Z. bend --i.e., "doubly tucked"
certainly is an apt (if unnecessary?) description for it, too.

Recall that for the R.Z. bend there is the variation where the continuation
from the SPart's turn around the ends is a full turn, i.e., continuing
to then collar the opposite SPart (not sure of benefits, but it's not
a big expansion from the R.Z.).  And it's unlikely to go a half-turn further
and get the sort of doubling that one might posit exists for the Dbl.Bowline
--the 540degree turn is just bulky w/o benefit, to my mind.

.:.  Use of "double" in knotting is currently problematic (used e.g. also for
eye knots w/2 eyes --a use I think should be out of bounds) ; can we see
a rationale to guide us in this?

--dl*
====
« Last Edit: December 02, 2010, 06:45:49 PM by Dan_Lehman »

roo

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Re: The asymmetric Zeppelin Bend
« Reply #8 on: December 02, 2010, 08:32:45 PM »
Quote
A "Double Zeppelin bend" is the name of a bend were either the collars or the nipping loops are doubled.
Says who?
 Me, that I have posted the thread about Double Zeppelins (1), and nobody said then that something similar has been mentioned earlier, neither you nor anybody else. 

This was an earlier mention:

http://igkt.net/sm/index.php?topic=1872.msg12783#msg12783

...but I'm certain this is not the first time such extensions have been explored. 
If you wish to add a troll to your ignore list, click "Profile" then "Buddies/Ignore List".


[Inkanyezi] gone

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Re: The asymmetric Zeppelin Bend
« Reply #9 on: December 04, 2010, 02:10:01 PM »
Of course my reason for choosing "asymmetric" in the header was the nigh to ridiculous verbosity recently about that feature.

And, I think it must be pointed out to those that do not readily understand it, that asymmetric is not the absence of a feature, but a different feature from symmetric. Asymmetric is quite as descriptive as symmetric, it just denotes a different feature. In this case the inline asymmetry of the two ropes, linear asymmetry, one dimension.

Also, I kept the name Zeppelin, because although a different knot will always result from a different tuck, the main features of the Zeppelin Bend are retained. The difference that may be experienced is that it takes a little more both to do and to undo. When the ropes are not too different in size, the knot is amply secure. It has also been pointed out, that a somewhat larger difference in sizes may require yet another tuck of the smaller line.  Still, the size difference should be reasonable. I think that anyone seriously into seamanship or rigging would understand such fuzzy logic.

The Zeppelin worked itself into my toolbox now; mainly from the loop form, where I managed to adapt it to my rather stringent criteria. The method I use now permits the knot to be formed with gloves and without the aid of vision. It is not a knot that I would use extensively; I seldom have to tie a bend, but occasionally I might need a bend for different size ropes without sacrificing security. There's where this beauty comes in.
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Dan_Lehman

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Re: The asymmetric Zeppelin Bend
« Reply #10 on: December 05, 2010, 03:48:24 AM »
It has also been pointed out, that a somewhat larger difference in sizes may require yet another tuck of the smaller line.

I once found a Fisherman's knot joining dissimilar-sized lines
(say, 5/8" + 3/8"?), and the smaller line's component had a further
tuck (making a topological double overhand, but not in the form
of a strangle knot, but an extended *pretzel* form).

 :)

[Inkanyezi] gone

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Re: The asymmetric Zeppelin Bend
« Reply #11 on: December 05, 2010, 05:36:11 PM »
It has also been pointed out, that a somewhat larger difference in sizes may require yet another tuck of the smaller line.

I once found a Fisherman's knot joining dissimilar-sized lines
(say, 5/8" + 3/8"?), and the smaller line's component had a further
tuck (making a topological double overhand, but not in the form
of a strangle knot, but an extended *pretzel* form).

 :)

I do use fisherman's, particularly the double variety, for junctions that are not supposed to be undone (mostly prussik slings), but the beauty I see in the Zeppelin is that it will not jam, but is always easily opened. So if I want to bend two dissimilar ends that I think of taking apart again, the Zeppelin with the smaller end doubly tucked might be the bend I prefer.
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[Inkanyezi] gone

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Re: The asymmetric Zeppelin Bend
« Reply #12 on: December 11, 2010, 12:21:23 PM »
Now I have tried the Zeppelin with many different size ropes, and it really is amazing how large difference that works with just one extra turn. There is no slip at all in this junction between a 4 mm and 18 mm rope. I have loaded it with my own weight, which is above the SWL of the thinner rope, and it did not slip the slightest. The only drawback is that it is a bit trickier to dress than with only one tuck, and also takes a little more work to open. This certainly will become my bend of preference for different sizes.
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[Inkanyezi] gone

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Re: The asymmetric Zeppelin Bend
« Reply #13 on: December 12, 2010, 08:46:59 PM »
There has been some doubt raised about the knot in the post above, whether it is a "zeppelin" or not. The knot is formed just as the other knots in this thread, by first forming a zeppelin bend, then following the WE with another turn, tucking it once more, hence doubly tucked with the thin end.

Here's an image of what the other face of the knot looks like:



The way it is tucked might be easier to trace at the picture inserted below:

« Last Edit: December 15, 2010, 06:36:40 AM by Inkanyezi »
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Dan_Lehman

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Re: The asymmetric Zeppelin Bend
« Reply #14 on: December 13, 2010, 01:06:26 AM »
It can be remarked that the form of the smaller-line's
knot component is a double overhand in the anchor
bend form (as opposed to an extended "pretzel" or
a strangle knot) --and that loaded in reverse to how
the named knot is loaded.

Well, one might try it the other way, too : i.e. make the
extra turn around the larger-line's tail (with the SPart),
and have but one finishing tuck; this uses an anchor
bend
(aka "fisherman's bend") with that knot's loading.
To my eye, this unshown version seems less desirable,
though it too works insofar as I've tried it.

I have found this "anchor bend form" to be useful in some
other messenger-line (thinner hitched to thicker) bends.

--dl*
====