International Guild of Knot Tyers Forum
General => Practical Knots => Topic started by: xarax on January 06, 2012, 11:35:10 AM
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A Zeppelin-like bend, but with an oval, and not a pointed oval ( = vescica piscis = fish-like, ιχθυς / ichthys = fish ) shape, as the shape of the original Zeppelin...THE original Zeppelin, meaning the Zeppelin airship, of course ! :)
Fully symmetric, nice, wide curves, and the timeless security of this marvelous rope-made hinge, the Zeppelin bend.
oval : http://en.wikipedia.org/wiki/Oval
vescica piscis : http://en.wikipedia.org/wiki/Vesica_piscis
ichthys : http://en.wikipedia.org/wiki/Ichthys
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I think that the connection between this and the so-called
"zeppelin bend" is less than strong (in the eye of one beholder),
especially in terms of characteristics (overhands or not,
non-jamming or not, ...). (Making a change to this I found
myself with the double harness bend.)
Meanwhile, the connection between the so-called knot
and its namesake has been challenged (in KM) as bogus.
What is true?
--dl*
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Thank you Dan Lehman,
I understand your reasonable argument about the connection with the Zeppelin bend, but, please, try to understand mine. :) As I have said many times, the main characteristic of the Zeppelin bend is not that it is just another interlinked overhand knots bend, but that it is different from them all ! It is not working with bights in an elbow, crossed configuration, i.e. hooked to each other, but by bights penetrated by a common two- elements pivot, the two tails. I have described this characteristic by the phrase " The Zeppelin bend is but a rope-made hinge". The tails do not slip through the bights, mainly because they are subject to strong, very effective friction-inducing shear forces ( and not because they are nipped into a nipping loop, and subject to compression and friction-inducing compression forces - as it is the case with most other interlinked overhand knots bends. Indeed, in the Zeppelin bend even loose bights can hold the tails at their position, which is impossible for most other overhand-based bends). That is exactly the situation with the Oval bend, too. See the tails, try to feel what they feel there, the strong, effective shear forces. The fact that the bend s links are topologically different from the Zeppelin bend s links is only of secondary importance here - as it happens with the Zeppelin X bend, too. The Zeppelin bend is not utilizing the topology of its links, because we do not have shrinking, constricting bights that nip and secure the tails. In the case of the Oval bend, modified, overhand knots-based links would also make no difference at all.
It is not a coincidence that I have arrived at this bend, studying the Zeppelin bend with parallel ends presented by SS369. Manipulating the Oval bend just a little bit, you can easily arrive at the Zeppelin bend, and vice versa.
Another factor that weighted in my decision to relate it with the Zeppelin bend, is its symmetry - very different from the symmetry of the Hunter s bend, for example.
I have not tested the jamming or not characteristics of this bend, but, as it is working just like the Zeppelin bend - by tails fixed in their place by shear forces - I guess that they will not be much different from those of the Zeppelin bend.
I do not know what is said in the Knotting Matters - and, frankly, I do not care ! Here is the public forum of the knots : , Hic Rhodus, hic saltus ! I am not aware of this bend been published anywhere previously... and you should have been convinced, by the first moment, or, at least, by now, that truth is something for which "I" do not allow any sales period ! If you are indeed furious to discover some bogus, you better look elsewhere ! Sorry for the harsh tone, but I am veeeery sensitive to some matters of honour, as you know ! :)
If there is another bend with the same name hidden somewhere else, and it is more oval than this :), I would be glad to change the descriptive name, I have chosen - which is, evidently the first thing that would come to anybody s mind.
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This "oval [bend]" looks like something a person fiddling in rather firm rope/cord might come up with; it is less likely to appeal to one fiddling soft/flexible material.
Because so much depends upon the mere tails of the knot preventing this capsizing, w/o additional support !
Tied in those cords of the latter character ... this knot can capsize --or, in my sole test loading, it has done so on one side only (and I manually forced the other initial u-turn to fold around the nub just so, for symmetry). The capsized knot has some interesting aspects,
I am almost sure that the knot can never be capsized from both sides by itself, without some manual / external intervention. However, the symmetrically capsized knot is interesting, indeed.
Tie two overhand knots at the ends of two ropes, and let the tail of each one knot go through / penetrate the other knot s loop, so that the two opposing tails are kept parallel and adjacent to each other. Then, retuck those two tails, each one through its own knot s loop. You have reached at the symmetrically capsized oval bend. In this form, the bend is remaining in one piece because the retucked tails act as the second legs of two collars, each collar going around the other overhand knot s rim, and each leg being nipped in between its own overhand knot s rim. The 4 : 1 mechanical advantage, together with the nipping of the tips of the collars into the overhand knots, are probably sufficient ways to greatly relieve the second legs of the collars, and keep the two links connected even under moderate loading.( See the attached pictures)
In fact, the knot is so well behaving, even in this degenerate form, that it might be called as another bend species ! :) Of course, this "bend" would work only if it is tied on very soft material - but then, the oval bend itself can be capsized in this form only if it is tied on such a material in the first plce.