We don’t have much historical data on the security and strength of the Zeppelin Bend. I opened this thread to talk specifically about the security and strength of the Zeppelin Bend relative to other knots. This topic is discussed a bit in some other recent threads, but it wasn’t the main topic.
Yes, this topic is wide open. Further define the parameters, as you see fit, in your replies.
Some questions for discussion:
How does the Zeppelin Bend compare against other bends that are known for NOT jamming easily (e.g., Double Sheet Bend, etc.)?
How does the Zeppelin Bend compare against other bends that are known for jamming easily (e.g., Double/Triple Fisherman Bend, Figure Eight Bend, Overhand Bend, etc.)?
To which you might have taken your fingers off of the keyboard and endeavored
to discover these geometric variations (and maybe offer additional assessment as
to their durability over a range of loading/force). Or do you think I made them up?
Schematically, the principal differences can be shown (font surviving
–oh, what we lose in non-ASCII! ) as below, the upper one showing SParts
surrounding cross-sections of tails oriented adjacent & parallel to tension,
with the lower one showing the tails oriented about 45deg to this, and so
giving the more gradual, stronger(?) curvature.
======\
O O
\======
=====\
O\
\ O
\======
Now, it could be that the issue is more subject to fine aspects of material,
and that what might look good at setting time will, when push comes to shove
towards a rupture force, be converted to the upper orientation.
I notice the telling absence of any mention to an erroneous previous claim
( that the Zeppelin bend feeds "generously" on its tails while it is been tightened ...
Which is hardly surprising (the absence, i.e.), as that wasn’t the point of discussion (strength).
But, it is certainly the case that the result of tying can vary per setting method,
and esp. in some materials more so than others it is necessary to pull the ends
to draw the knot up properly --otherwise, one has what might be referred to as
some kind of "opposed Bowlines " structure, each SPart leaning firmily
into one side of its collar vs. passing less firmly across its center.
I can not help but to pay attention to the results of other peoples keyboard,
I have to say, ...
But showing this attention by mere regurgitation of those results gets us
nowhere --we have the original instance, after all. (Though in some other
forums full copy-repetition is sometimes useful to preserve what is later
deleted --we don’t suffer that problem (deletion) here.)
My [i]theory[/i] is that, in the case of Zeppelin bend, the two tails (acting together, as a unified entity)
and the two loops of the overhand knots, function as [u][b] a pivot hinge [/b][/u]. Any subtle [b][i]geometric[/i][/b]
difference in this arrangement does not results in any n[i]oticeable[/i] difference of the bend s strength at all.
But that’s a non-responsive theory given the presented fact of geometric variance:
either you have to demonstrate that the variance doesn’t exist (or, as I suggest above,
exists in a sort of temporary & tenuous way only),
or you need to explain a theory of knot strength that makes the variance irrelevant.
Most of us are yet holding to some notion that curvature plays a role in strength
(though it might be less than we suspect, material variant (e.g., super slick stuff
not so much helped)), and so observations of effects on curvature rate at least
a worthy conjecture to the question. Just saying “I don’t think so” doesn’t help.
Pulling the standing ends would do the job, and the Zeppelin bend will dress itself to some
stable geometric form, that has nothing to do with the knot s strength.
This is demonstrably false. I suspect that in your moderately slick, firm, round
kernmantle ropes it is much true; but there are other ropes, and perhaps especially
laid ropes (having their surface groves for friction) well seasoned in the field
will behave differently, as will stiff ropes. This is readily seen with material in hand.
XaraX, you go beyond questioning to tiresome.
If you persist in screaming with your eyes shut tight, even the pretense
of a dialogue is gone. I have tried to explain things carefully; it is something
others at least can follow and try themselves. To the extent that I have
loaded the knot versions, they are different (and amply stable in their
differences).
As for that supposed uniqueness of Rosendahl’s bend re the ends making
a “pivot point”, we have already seen posted what belies that assertion
–the so-called “False Zeppelin”, with same-handed Overhands.
My interest in the Zeppelin Bend stems from explorations of failed bowlines. Climbers all know to secure bowline bitter ends, especially with kernmantle ropes whose smooth surface can slip free when loads are intermittent, such as rocking moored boat or swaying trees. In looking at Ashley, Butterfly, Hunters (aka Rigger’s) and Zeppelin Bends, I am impressed that whereas the first and third typically can jam, and the butterfly bend can be sometimes shaken free, the Zeppelin excels in all these areas. I believe it is because among all four of these “two-overhand-linked” simple bends, it and the Hunter have bitter ends emerging against and opposite each other. This I think means even loosely-dressed Zeppelin Bends, the moment a jerk is applied, press these bitter ends tightly and the ensuing friction prevents budging.
To this end, I am making directions so that one bitter end is employed as the start of a fixed loop, analogous to how the sheet bend becomes a bowline. Writing the directions for TYING this (is it new?) loop were difficult, but are shortly forthcoming. The resulting fixed loop I am just starting to test, but it seems to hold, loosely dressed, in 7 mm kernmantle rope, as a foot loop, being repeatedly jerked, it neither runs, jams nor unties. This same rope and test done to a unsecured bowline often loosens and fails, as is all too familiar. I am aware and do use the Yosemite finish on bowlines in non-test situations, and agree with its excellence, owing I believe to a similar factor as found in the Zeppelin: the bitter end emerges from the same loop as the SPart, and friction secures its position over all long-term uses.
The loop from the Zeppelin bend is well known - see http://notableknotindex.webs.com/zeppelinloop.html for example. Personally I use the alternative method shown for both the loop and the bend (though if teaching the bend I would use the “b & q” method). The loop certainly seems secure and is easily undone.
The direction the tails point to after they leave the knot s nub, has nothing to do whatsoever with the security or strength of the Zeppelin bend ( or of any bend…). We have dozens of bends with a similar aspect…
For the uniqueness of the Zeppelin bend in relation to the tails functioning as shear-forces-bearing pivots of a rope-made hinge, search for the terms “pivot”,“hinge”, “shear” in this forum.
The so-called “Zeppelin loop”, is a loop based on the topology only of the Zeppelin bend, but not on its mechanism / function. ( So, the name of this loop is, in fact, misleading ). When a third end of the Zeppelin bend is loaded, the knot behaves in an entirely different way than the most symmetric original bend. The situation is similar with the bowline, where we can not speak of having a Sheet bend any more - because what we really have has a superficial only resemblance with the one link of the Sheet bend. When both ends of this link are loaded, as it happens in the bowline, we do not have a Sheet bend any more, we have a bowline !
Any secure bend can be transformed into a secure loop. There is no point of doing this with the Zeppelin bend or with any other bend, because we have dozens of secure bowline-like loops, which have the additional great advantage to get completely untied the moment you pull out the tail.
Although I mostly agree on Xarax’s post, I disagree on the last sentence. It is not always an advantage that a knot is very easy to undo by just withdrawing one tuck. The security of the Zeppelin Loop may well override this perceived disadvantage.
I haven’t done any actual testing of this very knot, but when I tested various knots in monofilament fishing line, I came to the conclusion that it is important to lubricate the knot when drawing it up. Fishermen often do this with saliva, wetting the line, so that it glides smoother till the knot sets well. Invariably I found knots that were not licked on breaking against one that was spitted on.
Perhaps I should have better said “convenience” instead of “advantage”…
However, I insist that there are dozens of bowline-like loops that are at least as secure as the so-called " Zeppelin loop" - i.e. they will break before they will start to slip. What is the point of choosing in the first place and then using one out of the many bends-turned-into-loops, especially when it is now tied in a quite different, more complex way than the simple way we use to tie the original knot ?
As much as I admire THE Zeppelin knot, the bend, I detest the so-called “Zeppelin loop”…It is like using gold because it is a heavy metal…
But those bowline variations are often less secure, or less stable in different load configurations, or harder to adjust, or harder to inspect for errors because they’re a mess, or use more rope, etc.
Keep in mind that if untying the Zeppelin Loop (even with its final loose overhand knot) takes less time than prying apart a less jam-resistant loop, you are gaining something in this regard.
This is NOT a good definition of security. Nearly all knots are more vulnerable from slack shaking than from slipping at high strain. Most knots never just slip out of the rope at high strain unless you’re using exotic low friction rope at high loads.
Noope. They are stable in each and every load configuration.
Noope. On the contrary, the so-called “Zeppelin loop” is quite hard to adjust…
Noope. Many of them are symmetric, neat, easy to remember how to tie and easy to inspect knots. On the contrary, the so-called “Zeppelin loop” is so badly deformed - in other words, is such a mess - ( because the one tail of the original Zeppelin knot is now loaded ) , that even the mother of the Zeppelin bend herself would not be able to recognize it !
Noope. I have actually measured their rope length, and I have found that quite the opposite is true ! On the contrary, the so-called “Zeppelin loop” uses almost the same amount of rope the bend uses, to secure one only tail, i.e. it uses the same means to achieve half of the task of the original knot - which is not exactly a definition of economy, is it ?
Judging from their form alone, I suppose that there are many secure bowline-like loops at least as jam-resistant as the so-called “Zeppelin loop” - but I admitt I have not actually measured this quantity that is called “jamming”- simply because I do not know yet how to measure it…
ALL knots are 100% vulnerable to be untied, if they are left loose enough, if that is what you mean… For me, security=no slippage under high load, even near the breaking strength of the knot - and strength=no breaking before the load reaches a high percentage of the breaking strength of the rope.
“I” write what I think is true, and you think that what “you” write is true. Some difference !
The secure bowline-like loops do not need an overhand knot tied on the standing part, they do not even need a closed nipping loop on the standing part, as we have seen recently (1). Of course, if one does not know them, or does not even want to learn them, he can always tie the first bend that crosses his mind, as a loop, and be satisfied with the cleverness of the result… To me, to be able to tie a secure loop around a ring or bollard, without having to tie an overhand knot on the standing part first, is a wonderful gift from the Knot Land offered to us, almost a miracle we are not allowed to ignore.
I have explored the field of bends and the field of loops as well for some time now, and I have been driven to the conclusion that they are two quite different things we should not confuse. Bends are symmetric, two-loaded-ends knots, loops are not. Big, huge difference. A good bend can always serve as a so-so loop - as it happens in the case of the Zeppelin knot - but a knot tyer would never be deceived by the apparent similarity, and would never be satisfied with the “usefulness” of an ugly monster that does not belong to the one or the other field. We are talking about knots here, I suppose, not about “every-tangle-thing”, and to knot tyers, not to "everybody’…otherwise we can always pass our free end around the object five, ten, or even a hundred times, and have our job done !
So, yes, “I” write what I think is true, but there will be always people that are not interested in truth, and will not never ever read what I write. It makes me wonder if they have ever read anything else, except what “they” think they have written…
I don’t think Xarax meant that one can simply undo one
tuck, but that having unreeved the tail, there is no knot
remaining in the rope (i.e., the nipping turn of the SPart
disappears) --unlike for most other eye knots, such as the
commonly used fig.8 eye knot & zeppelin eye knot.
But I do disagree that any end-2-end knot can produce
a suitable eye knot : the squaREef knot doesn’t do this
–but, yes, it certainly is (like or not) an end-2-end “bend”.
Let’s kill the “bitter” mis-use (it should refer to bitts);
“end” or, better?, “tail” will suffice, nicely.
As for (rock)climbers knowing about the bowline,
that is demonstrably not true, for all --hence some
of the issues your explorations might’ve found.
But awareness is growing (one hopes).
In looking at [i]Ashley, Butterfly, Hunters (aka Rigger's) and Zeppelin Bends[/i], I am impressed that whereas the first and third typically can jam, and the butterfly bend can be sometimes shaken free, the [i]Zeppelin[/i] excels in all these areas.
The issue about the first “typically can jam” I hope
I’ve put to rest in a thread here, about 6 months ago?
There are various ways to dress the knot --which can
be varied per need–, including one dressing in which
there is no jamming. I’ve put this to some testing
in normal materials. And SmitHunter’s bend has a
simple version that pretty well resists jamming (just
cross the tails …). Oh, by “Ashley”, we should append
a qualifier to that --“1452”. He also introduced #1408
and #1425, which are jam resistant (the first being
what I regard as a symmetric “butterfly”).
As to your conjecture about opposed tails giving some
benefit to security, I don’t buy it so much. There are
cases where tails move opposite each other, as well as
some cases where there is apparently some assistance
of slippage by ends moving together. Here, I think that
the security comes from a hard nip relative to the forces
on the tails (irrespective of their direction of pull). And
the slack-security (something Xarax seems to ignore,
as a quality aspect) comes from the particular angle at
which the tails reach their final tucks (so that they just
aren’t so pulled towards loosening?!).
All that said, there are some quite simple bowline extensions
that do well to add security, maybe even a bump of strength
–putting a 3rd or 4th diameter in the central nipping loop–,
so that rope users can meet their needs with that knot.
Like in the case of Xarax, I leave something to the reader’s fantasy, and you might imagine that I didn’t intend to say that any bend will make a good loop when one of the ends is taken back. However, in the case of the Zeppelin, the resultant knot is secure and easily untied. Like for most other knots, I am not particularly concerned about strength, but there is a difference between boating and rock climbing, both regarding materials and perceived security. After all, boating lines are sufficiently secure with a bowline; I have used it for fifty years without a single failure. Also I never had a mooring line break. I remember in my youth a halyard that broke, three strand cotton. I never used cotton for a halyard since.
So I’ll stick to tying up my boat with a bowline in one end, and I know the Zeppelin and the loop form of it well enough, but there’s little chance that I would use it other than as a demonstration.
I do ! And many of them - probably most of them - are better as loops (eye knots) than as bends ( end-to-end knots) !
Now, I also can discover one or two exceptions to this self evident truth, ( if I try as hard as Dan_Lehman did ), but not many more… ( A handful of exceptions, in more than two hundred bends I have taken pictures of, AND all the bends posted in Ashley and/or Miles…can not falsify this general rule, I suppose.)
