International Guild of Knot Tyers Forum

General => Practical Knots => Topic started by: knot4u on July 02, 2010, 06:57:55 PM

Title: Zeppelin Bend: Security and Strength
Post by: knot4u on July 02, 2010, 06:57:55 PM
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.)?

Here are some pretty cool stress tests on Zeppelin Bend:
http://www.youtube.com/watch?v=Givv9cBB_Hw&feature=related
http://www.youtube.com/watch?v=_-uQrx7yPYM&NR=1

I won't summarize the videos.  I'll let you watch!  ;)

Here's a source that shows tests results of the Double Sheet Bend, Double Fisherman Bend, Figure Eight Bend and some others:
http://www.xmission.com/~tmoyer/testing/High_Strength_Cord.pdf
http://www.caves.org/section/vertical/nh/50/knotrope.html

I have not seen a comprehensive test that includes the Zeppelin Bend versus other bends.
Title: Re: Zeppelin Bend: Security and Strength
Post by: Dan_Lehman on November 19, 2010, 07:37:57 PM
."
   Dan Lehman replied that :
   "There is a noticeable difference of geometry if one orients the knot's tails in a certain way.  In the simple and commonly presented geometry, they align adjacent on the axis of tension, SParts making a 1-diameter turn around them; but in the version I intend, the Sparts turn more broadly, and that is what leads me to conjecture "greater strength".  Getting this orientation takes some careful placing of the ends and then careful setting --dressing AND setting are mindful acts."
   " In the disposition of the knots' tails, I see a trio [at least] of orientations for Rosendahl's bend ."

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.

Quote
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.

Quote
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.)

Quote
My theory 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 a pivot hinge . Any subtle geometric
difference in this arrangement does not results in any noticeable 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.


Quote
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.

--dl*
====
Title: Re: Zeppelin Bend: Security and Strength
Post by: Dan_Lehman on November 20, 2010, 05:45:54 AM
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.

--dl*
====
Title: Re: Zeppelin Bend: Security and Strength
Post by: youngknot on January 17, 2012, 12:41:53 PM
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.
Title: Re: Zeppelin Bend: Security and Strength
Post by: Sweeney on January 17, 2012, 02:01:38 PM
The loop from the Zeppelin bend is well known - see http://notableknotindex.webs.com/zeppelinloop.html (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.

Barry
Title: Re: Zeppelin Bend: Security and Strength
Post by: xarax on January 17, 2012, 02:27:14 PM
have bitter ends emerging against and opposite each other.

  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.

   
Title: Re: Zeppelin Bend: Security and Strength
Post by: [Inkanyezi] gone on January 17, 2012, 05:34:25 PM
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. 

I opened a subject on the board about a tying method for this in http://igkt.net/sm/index.php?topic=2146.msg15093#msg15093

If you, in the third image, imagine the end coming back to complete the knot, you have a tying method for the loop.
Title: Re: Zeppelin Bend: Security and Strength
Post by: [Inkanyezi] gone on January 17, 2012, 05:37:48 PM
/.../   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.
Title: Re: Zeppelin Bend: Security and Strength
Post by: [Inkanyezi] gone on January 17, 2012, 05:48:07 PM
Here are some test results that go against conventional wisdom.  I just did some testing with the the Zeppelin Bend on fishing line, and the results were surprising.

Using 10 pound test monofilament, I tied a Zeppelin Bend in the same line as an Albright Special.  I used a magnifying glass to inspect proper dressing and started over if I thought a knot was dressed improperly.  I pulled the line on each end until something broke.  The line broke at the Albright Special.

I repeated this test 5 times and received the same result each time.  The line consistently broke at the Albright Special and not at the Zeppelin Bend or anywhere else.  By the way, the Zeppelin Bend jams up in 10 pound test monofilament.

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.
Title: Re: Zeppelin Bend: Security and Strength
Post by: xarax on January 17, 2012, 05:58:16 PM
The security of the Zeppelin Loop may well override this perceived disadvantage.

   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...  :)
Title: Re: Zeppelin Bend: Security and Strength
Post by: roo on January 17, 2012, 06:00:31 PM
  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.
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.
Title: Re: Zeppelin Bend: Security and Strength
Post by: roo on January 17, 2012, 06:02:17 PM
[on security]
 - i.e. they will break before they will start to slip.
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.   
Title: Re: Zeppelin Bend: Security and Strength
Post by: xarax on January 17, 2012, 07:26:07 PM
But those bowline variations are often less secure
Noope. They are 100% secure, always secure... :)
But those bowline variations are...less stable in different load configurations
Noope. They are stable in each and every load configuration.
But those bowline variations are... harder to adjust
Noope. On the contrary, the so-called "Zeppelin loop" is quite hard to adjust...
But those bowline variations are...harder to inspect for errors because they're a mess
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 !  :)

But those bowline variations ...use more rope
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 ? :)
a less jam-resistant loop
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...

[on security] - i.e. they will break before they will start to slip.
This is NOT a good definition of security.  Nearly all knots are more vulnerable from slack shaking than from slipping at high strain.

   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.


Title: Re: Zeppelin Bend: Security and Strength
Post by: knot4u on January 17, 2012, 11:01:34 PM
   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.

Or you can just tie a Double Dragon.
Title: Re: Zeppelin Bend: Security and Strength
Post by: roo on January 18, 2012, 04:58:49 AM
But those bowline variations are often less secure
Noope. They are 100% secure, always secure... :)
But those bowline variations are...less stable in different load configurations
Noope. They are stable in each and every load configuration.
But those bowline variations are... harder to adjust
Noope. On the contrary, the so-called "Zeppelin loop" is quite hard to adjust...
But those bowline variations are...harder to inspect for errors because they're a mess
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 !  :)

But those bowline variations ...use more rope
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 ? :)
a less jam-resistant loop
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...

[on security] - i.e. they will break before they will start to slip.
This is NOT a good definition of security.  Nearly all knots are more vulnerable from slack shaking than from slipping at high strain.

   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.

Wow.  All bowline variations are everything to everyone ::).  It makes me wonder if you even read what you write.
Title: Re: Zeppelin Bend: Security and Strength
Post by: xarax on January 18, 2012, 08:35:00 AM
Wow.  All bowline variations are everything to everyone ::).  It makes me wonder if you even read what you write.

   "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...

1. http://igkt.net/sm/index.php?topic=3020.msg21688#msg21688
Title: Re: Zeppelin Bend: Security and Strength
Post by: Dan_Lehman on January 18, 2012, 05:59:14 PM
/.../   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 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".

--dl*
====
Title: Re: Zeppelin Bend: Security and Strength
Post by: Dan_Lehman on January 18, 2012, 06:29:41 PM
My interest in the Zeppelin Bend stems from explorations of failed bowlines.
!?  How have you explored failed bowlines ?

Quote
bitter ends,

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).

Quote
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.

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.


--dl*
====
Title: Re: Zeppelin Bend: Security and Strength
Post by: [Inkanyezi] gone on January 19, 2012, 12:07:41 AM
/.../   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 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".

--dl*
====

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.
Title: Re: Zeppelin Bend: Security and Strength
Post by: xarax on January 19, 2012, 08:56:55 AM
I didn't intend to say that any bend will make a good loop when one of the ends is taken back.

  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.)
Title: Re: Zeppelin Bend: Security and Strength
Post by: youngknot on January 19, 2012, 03:34:16 PM
I am grateful for all the references and especially Sweeney's web reference.  The alternative method is what I had worked out; the modification of the "b-q" method makes the derivation from the bend much clearer.  Good stuff!
It is clearly true as Xanax says, that taking one bitter end of a bend knot into a loop may utterly shift the forces into another shape, leaving many features and bringing on a whole collection of problems.  The Carrick Bend as tied, flat looks nothing like spilled and formed into a proper bend where force can be resisted.  In the summer of 1959, a Maine lobsterboatman, Elmer Osier, showed me the method of tying a bowline which begins with a slip knot waiting in the SPart and throws the free end around an approaching wharf and through it loosely, spilling it into a proper bowline.  At the time, I was quite impressed at how knots become sometimes what you least expect, and Xanax's points are well taken.  For my part, as a practicing ecologist, the Zeppelin Loop was new ground, at least worth trying, and although I think online discussions might approach overloading the ties that otherwise bind us, I do value everyone's contributions--thanks.
Title: Re: Zeppelin Bend: Security and Strength
Post by: roo on January 19, 2012, 05:48:00 PM
I am grateful for all the references and especially Sweeney's web reference.  The alternative method is what I had worked out; the modification of the "b-q" method makes the derivation from the bend much clearer.  Good stuff!
It is clearly true as Xanax says, that taking one bitter end of a bend knot into a loop may utterly shift the forces into another shape, leaving many features and bringing on a whole collection of problems.  The Carrick Bend as tied, flat looks nothing like spilled and formed into a proper bend where force can be resisted.  In the summer of 1959, a Maine lobsterboatman, Elmer Osier, showed me the method of tying a bowline which begins with a slip knot waiting in the SPart and throws the free end around an approaching wharf and through it loosely, spilling it into a proper bowline.  At the time, I was quite impressed at how knots become sometimes what you least expect, and Xanax's points are well taken.  For my part, as a practicing ecologist, the Zeppelin Loop was new ground, at least worth trying, and although I think online discussions might approach overloading the ties that otherwise bind us, I do value everyone's contributions--thanks.
The Zeppelin Loop is a good one.  You'll be hard pressed to find a loop that remains stable and secure in slick bungee under high strain and still remain easy to untie, for example.  Those benefits also translate into less radically elastic line.

The loop reduces one of the standing parts of the bend to 50% of the parent line load (from 100%).  It also increases the load on the one of the free ends of the corresponding bend from 0% to about 50%.  This does not adversely affect the core knot form in terms of either stability or its excellent jam resistance. 

Title: Re: Zeppelin Bend: Security and Strength
Post by: Dan_Lehman on January 20, 2012, 12:06:45 AM
The Carrick Bend as tied, flat looks nothing like spilled and formed into a proper bend where force can be resisted.  In the summer of 1959, a Maine lobsterboatman, Elmer Osier, showed me the method of tying a bowline which begins with a slip knot waiting in the SPart and throws the free end around an approaching wharf and through it loosely, spilling it into a proper bowline.

Where some other commercial fishermen are concerned,
the tying of the carrick bend doesn't use that lattice-like
form, but is done by folding one end into shape and then
reeving the other through it (which can lead to some
different results if botched) --done like this, apparently,
in the stiff, hard-laid pot warp of Alaskan crabbers when
extending the lines.  (It is an application I think that would
suit the zeppelin end-2-end knot quite well.)  That
losterman probably used a fisherman's knot or maybe
water knot .  Some decades back, someone reported
in Knotting Matters that to his experience the lobstermen
around Boston were nearly divided into (warring) camps and
distinguished by which end-2-end knot they employed!

The marlinespike-hitch-into-bowline maneuvre can be some
help, but one should beware that sudden loading as has
been described here & elsewhere can lead to things
other than a well-formed eye knot --the capsizing might
not go as desired, given roughness & loading of the line!
YMMV.


--dl*
====
Title: Re: Zeppelin Bend: Security and Strength
Post by: Dan_Lehman on January 20, 2012, 12:10:56 AM
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'm reminded of reading one sailor's remark concerning
strength that, even after a hurricane had ravaged some
marina(s) of moored boats, no lines broke at the knot (and
most didn't break), but elsewhere.


--dl*
====
Title: Re: Zeppelin Bend: Security and Strength
Post by: youngknot on January 27, 2012, 06:29:31 PM
Thanks again for all the perspective and information.  To answer one question: I feel it is important making knot statements to relay with what range of cordage you have experience.  "Bowline" security in my experiences, ranges from monofilament line, through laid nylon and polypro stuff, to 7/16 kernmantle inelastic cave standing ropes (Bluewater II), coated with ice and limestone mud--- infrequently over about five decades.  I have never had a problem except with monofilament or new 7 mm nylon kernmantle, and only with jerking--by which I mean where the line is repeatedly relaxed alternating with drawn up tight and hard.  An unsecured bowline, well formed by hand, simply in the last two cases, after 10 - 30 jerks, unties.  As I mentioned in my first post, whenever I even suspect in any USE, that there is that possibility in store, I use some extra security, such as the Yosemite finish and perhaps a couple of half hitches.  I do not consider what others look at as exaggerated security a waste of time, even with numb fingers.  Well-formed bowlines with no added finishing I have never seen fail from untying in stout well-laid ropes > 1/2 inch - - but then, I've never owned a Zeppelin tossing in the wind.
I have previously worked alone, and having now thoughtful colleagues with whom to discuss knot matters is a privilege, again, thanks.
Regarding the other bends formed by two linked overhands, I was fascinated by their symmetry.  Owning no knot reference besides Clifford's remarkable 1944 achievement at hand, I began by studying overhand knots, proved to my satisfaction there are only two, I called L and D, for levo- and dextro-rotary (for the spirals formed, LH and RH threaded screws).  For morphology, I named the two crescent-shaped holes in overhands "A" (next to SPart) and "B" (by the tail).  The large opening I called "O".    So now I can write typing directions using these named holes and symmetry descriptors, by which to study the four bends I first mentioned. 
By coincidence,  the four arrange themselves alphabetically in my key:
1. tails emerge in same direction:
00    overhands same: Ashley Bend (Thanks Dan, #1452)
01    overhands mirror images: Butterfly Bend (these attributes are inevitable for the only one to be tied on a bight)
2. tails emerge opposite directions
10   overhands same: Hunter (aka Smith or Riggers)
11   overhands mirror images: Zeppelin or Rosendahls
Alphabetical, at least using these as names.
In closing, I'll note you all may likely know these curious facts --- and/or the exceptions of which I will soon be gratefully educated.  Thanks in advance. Regards.
Title: Re: Zeppelin Bend: Security and Strength
Post by: xarax on January 27, 2012, 08:33:42 PM
Regarding the other bends formed by two linked overhands, I was fascinated by their symmetry. 

Hi youngknot,

   There are dozens of interlinked-overhand-knot bends, and if we take into account all their variations, ( including the "double" ones ), there are dozens of dozens, indeed !
   You can find almost all of them in this forum, if you search for the relevant words, "bends", and "overhand". The Zeppelin bend stands in a class of its own, as you will find out.
   The most easy way for one to start, the way I suggest to people, is to form one reef knot "base", and re-tuck it. See the attached picture, for one of the eight such bases). That way you will get the Ashley bend (ABoK#1452), the Alpine Butterfly bend, the ABoK#1408 bend, the Hunter s bends, the Shakehands bends, and the Mark s bends. Those are the most well known bends, and a sure place to start one s journey to the world of bends.
   The same can be said for the bowline-like bends, where we have also the very nice compilation of bowlines by Mark Gommers, at (1). Search for "bowline", and you will discover many things here, that you are not going to find elsewhere.
   Welcome to the forum. We need new knot tyers, especially if they are young !  :)

1) http://www.paci.com.au/downloads_public/knots/02_Bowlines.pdf
Title: Re: Zeppelin Bend: Security and Strength
Post by: Dan_Lehman on January 27, 2012, 09:14:39 PM
I feel it is important making knot statements to relay with what range of cordage you have experience.

Amen!!  It is amazing to watch a video of a double bowline
(with stoppered tail) just collapsing its eye as material *flows*
out of the knot through those double turns!!  --"Huh, it can DO that?!"
was my thought.  And the end-bound double bowline I thought
so secure (well set; and meaning "secure-when-slack", vs. jostling),
showed a lack of that in some slick, springy, laid polypropylene cord,
where all the engaged loops binding upon each other just loosened
simultaneously, after holding briefly (!).

Quote
I use some extra security, such as the Yosemite finish and perhaps a couple of half hitches.  I do not consider what others look at as exaggerated security a waste of time, even with numb fingers.  Well-formed bowlines with no added finishing I have never seen fail from untying in stout well-laid ropes > 1/2 inch - - but then, I've never owned a Zeppelin tossing in the wind.

Consider some of the bowline extensions presented in
the "paci" PDF file Xarax points to.  I can see taking one of
the "Janus" variations and extending that to make one further
collaring (of the SPart) and tucking of the tail (to point, now,
back towards the eye) --makes for a lot of unreeving to occur
AND not be noticed; maybe bumps strength, lessens wear?

As for "zeppelin", know this:  there is now considerable doubt
that (1) such an end-2-end knot was ever needed & used for
those airships, and (2) that Cmdr. Rosendahl had the slightest
awareness of it --there is writing from him to support this belief.
So, count one more knot myth, though it's a mystery of why it
was created (the myth), and where the knot might've originated.


--dl*
====
Title: Re: Zeppelin Bend: Security and Strength
Post by: xarax on January 27, 2012, 09:39:35 PM
As for "zeppelin"...count one more knot myth, though it's a mystery of why it was created (the myth), and where the knot might've originated.

   Myths are generated/created in all fields of human practice, why do they have to respect knotting ? I would like to contribute to this mythology a little bit, with two myths made by me :
  1. Zeppelin, the inventor of the Zeppelin airship, served in the US army as a volunteer. Rosenthal inherited the knowledge of the knot, along with the Zeppelin airships... :)
   2. Ashley knew the Zeppelin knot, but decided not to publish it, because it was invented by a (German) enemy :  The proof that he knew it, is ABoK#582 stopper - which is the Zeppelin bend turned into a stopper ( and so disguised ! )  :) (See 1)

1)   http://igkt.net/sm/index.php?topic=2816.msg17243#msg17243
Title: Re: Zeppelin Bend: Security and Strength
Post by: roo on January 27, 2012, 09:48:06 PM

As for "zeppelin", know this:  there is now considerable doubt
that (1) such an end-2-end knot was ever needed & used for
those airships, and (2) that Cmdr. Rosendahl had the slightest
awareness of it --there is writing from him to support this belief.
So, count one more knot myth, though it's a mystery of why it
was created (the myth), and where the knot might've originated.
Rosendahl has been dead for quite some time (since 1977!).  Where's this evidence that he never had any awareness of the bend in question?  It sounds very fishy to me.

I also find it hard to believe that various grounding lines or other lines were never bent to other lines.   

See:
http://tinyurl.com/6qzqe4m
http://tinyurl.com/7g3hjtp
http://tinyurl.com/75weqr5
http://www.motherearthnews.com/homesteading-and-livestock/zeppelin-knot-zmaz80jfzraw.aspx#axzz2XLitgA8w
Title: Re: Zeppelin Bend: Security and Strength
Post by: Dan_Lehman on January 29, 2012, 07:17:45 AM

As for "zeppelin", know this:  there is now considerable doubt
that (1) such an end-2-end knot was ever needed & used for
those airships, and (2) that Cmdr. Rosendahl had the slightest
awareness of it --there is writing from him to support this belief.
So, count one more knot myth, though it's a mystery of why it
was created (the myth), and where the knot might've originated.
Rosendahl has been dead for quite some time (since 1977!).  Where's this evidence that he never had any awareness of the bend in question?  It sounds very fishy to me.

I also find it hard to believe that various grounding lines or other lines were never bent to other lines.

Apparently you don't read Knotting Matters !

In it, Dr. Giles Camplin, with a PhD. focusing on airships history,
recounts how he came to know about the "zeppelin" knot
--from a reprint of the 1976 Payne brothers' Boatingarticle
reporting what some "Joe Collins" is supposed to have said.
But in this particular (Wingfoot Journal) reprint, there was
a most intriguing footnote, which Giles recounts:

<<Lee Payne of Balboa, Calif., one of the
authors,  wrote to me  [Presumably the
Wingfoot Editor (1980)]  about this article,
"Admiral Rosendahl wrote to me [Lee Payne]
to say that the Los Angeles? crew was trained
at Lakehurst rather than at Norfolk as stated in
the article, and that he had never heard of the
Rosendahl bend
but that 'it is slightly possible
that no one ever told me of it.  In any event I am
glad you think so highly of it.'  "

>>

--just in the nick o' time, given Rosendahl's life!
Enough said, though?
We must still wonder about the "Joe Collins" account.
Research can check to see if he exists as a bona fide
person in Naval files, as well as to check on the
alleged stations of sailors & training.

Further, in communication w/me about the issue,
Giles wrote
Quote
My further, more recent research into Airship Ground Handling
for my Ph.D thesis (2007) has now led me to find it very difficult to see
where and when this knot could've been used as a standard part of the
mooring procedure.


--dl*
====

Title: Re: Zeppelin Bend: Security and Strength
Post by: roo on January 29, 2012, 09:11:22 AM
Apparently you don't read Knotting Matters !

In it, Dr. Giles Camplin, with a PhD. focusing on airships history,
recounts how he came to know about the "zeppelin" knot
--from a reprint of the 1976 Payne brothers' Boatingarticle
reporting what some "Joe Collins" is supposed to have said.
But in this particular (Wingfoot Journal) reprint, there was
a most intriguing footnote, which Giles recounts:

<<Lee Payne of Balboa, Calif., one of the
authors,  wrote to me  [Presumably the
Wingfoot Editor (1980)]  about this article,
?Admiral Rosendahl wrote to me [Lee Payne]
to say that the Los Angeles? crew was trained
at Lakehurst rather than at Norfolk as stated in
the article, and that he had never heard of the
Rosendahl bend
but that 'it is slightly possible
that no one ever told me of it.  In any event I am
glad you think so highly of it.'?

>>

--just in the nick o' time, given Rosendahl's life!
Enough said, though?
We must still wonder about the "Joe Collins" account.
Research can check to see if he exists as a bona fide
person in Naval files, as well as to check on the
alleged stations of sailors & training.
:o
How many layers of hearsay do we have here?!   Has anyone verified the contents and authenticity of this letter from Rosendahl that supposedly was sent to Payne which then was supposedly written about to the Wingfoot editor?  I'm betting that neither of these two letters even exist anymore.  This is so bad, it makes me wonder if anyone can track down the Wingfoot article.

Even if this Rosendahl letter is found and verified, who is to say that at the age of 84 he simply didn't recall a bend he may not have thought about for decades, and which may have been presented in a different way?
Title: Re: Zeppelin Bend: Security and Strength
Post by: youngknot on January 29, 2012, 05:25:49 PM
All to the point, thanks to xarax, Dan and roo, although I might add the only thing at all young about me is my knot knowledge. (Perhaps "young,NOT" would be more appropriate).
My claim to be keying out the four knots I listed was based on reading other web sites; now that I am surrounded by more knowledge, perhaps I have obtained a modicum of slack.  History has always fascinated me, but years ago I noticed that it often depends on who is telling it, so my life has more nearly pursued the sciences, but never knots except when life or tree limb were in the balance.  I will certainly pass on Mark's bowline analysis to my young grandson, Ambrose, whose penchant for inventing (and later reproducing) knots has his parents mystified and myself chuckling. 
Re negotiating overhand knots, I attach a diagram I prepared before Dan explained your accepted use of "tails". I use D as in Dextrose, because the twist portion of the knot forms a right-hand-thread screw.  I found the labeled openings a great help in following and writing about the reeving process. My regards.
Title: Re: Zeppelin Bend: Security and Strength
Post by: Dan_Lehman on January 29, 2012, 07:36:53 PM
:o
How many layers of hearsay do we have here?!   Has anyone verified the contents and authenticity of this letter from Rosendahl that supposedly was sent to Payne which then was supposedly written about to the Wingfoot editor?  I'm betting that neither of these two letters even exist{s} anymore.  This is so bad, it makes me wonder if anyone can track down the Wingfoot article.

Even if this Rosendahl letter is found and verified, who is to say that at the age of 84 he simply didn't recall a bend he may not have thought about for decades, and which may have been presented in a different way?

"Hearsay", you say?!  "so bad..." !!
--in contrast/competition to what, exactly, otherwise?

Are you so secure in your tower upon one article's assertion
from some "Joe Collins"'s hearsay about what Rosendahl did
that you deny Rosendahl himself contrary argument?  Do note
that Lee Payne is co-author of the article and supplier of the
R. assertions, so that is the same hearsay-link for both sides.
(Actually, IIRC, it's Lee's brother Bob who connected with the
supposed Joe, and I'm forgetting it it was even clear whether
the two brothers had actual contact w/"Joe" or if their article
arose on Bob's hearsay of Joe !)

We know at least that Rosendahl existed; do we know this
about Collins?  If we can, by naval records, find no evidence
of this Collins (though among ample records otherwise),
that raises an obvious question.  And if there is no record
otherwise about the supposed required special knot to do
some service (that a student of airship mooring cannot
conceive of!), that too raises questions --wouldn't a military
organization have made mimeographed tying instructions
issued to rope handlers so that they could learn the knot?

And do you also think that Rosendahl and not Collins was
confused about where the alleged training occurred?  --this,
too, would be a serious dent in the latter's credibility if it
could be shown that, by extant records of his existence
in the navy, Collins was never at one of these places (and
so would have no reason for getting it wrong).

The best you can say on the Rosendahl commentary is
Why did HE NOT raise the question about how any such knot [red added 20171108]
could play a roll (as does Giles)?!
--a fair point, that.
Except that one answer that springs to mind is that Cmdr.R.
was so knot-NOT-savvy that he simply had no clue, in such
matters : that hardly speaks to his having originated or
even insisted upon some particular, novel knot.

My weak surmise is that this Joe Collins did exist, and was
perhaps the orginator of the knot, but wanted to make a
*legend* for it (harkening to Tinker,Taylor,Soldier,Spy
concluding book Smiley's People reputed spy jargon
for getting a cover story for someone).


--dl*
====
Title: Re: Zeppelin Bend: Security and Strength
Post by: xarax on January 29, 2012, 10:48:16 PM
   I repeat the (one) myth I proposed at reply#27, this time as a question :
Is it possible that Ashley was not aware of the Zeppelin bend, when he presents the same knot structure, as a stopper, at ABoK#582 ?
Title: Re: Zeppelin Bend: Security and Strength
Post by: roo on January 30, 2012, 01:25:28 AM
"Hearsay", you say?!  "so bad..." !!
--in contrast/competition to what, exactly, otherwise?
It's layers of hearsay on its own!  Where's the letter from Rosendahl that we can authenticate and verify for content?  We can't even produce the letter that refers to it!  THAT is bad... really bad.

Quote
Are you so secure in your tower upon one article's assertion
from some "Joe Collins"'s hearsay about what Rosendahl did
that you deny Rosendahl himself contrary argument?  Do note
that Lee Payne is co-author of the article and supplier of the
R. assertions, so that is the same hearsay-link for both sides.
(Actually, IIRC, it's Lee's brother Bob who connected with the
supposed Joe, and I'm forgetting it it was even clear whether
the two brothers had actual contact w/"Joe" or if their article
arose on Bob's hearsay of Joe !)
At least in the Collins interview, the journalists are contacting someone with first-hand knowledge of the bend's use (assuming Joe's not making it up).  Joe could have been contacted at the time of the article for people who wanted to find out more. 

Quote
We know at least that Rosendahl existed; do we know this
about Collins?  If we can, by naval records, find no evidence
of this Collins (though among ample records otherwise),
that raises an obvious question.

That would be a better route to pursue.  It would far more directly prove that Joe Collins was a fraud.

Quote
And if there is no record
otherwise about the supposed required special knot to do
some service (that a student of airship mooring cannot
conceive of!), that too raises questions --wouldn't a military
organization have made mimeographed tying instructions
issued to rope handlers so that they could learn the knot?
No, that trail is fruitless.  Every organization has tribal knowledge in some quarters that is not officially promulgated.

Quote
And do you also think that Rosendahl and not Collins was
confused about where the alleged training occurred?
This is pointless on two counts:
1)  We cannot verify the contents of the missing Rosendahl letter.
2)  Even if Collins got this wrong, it could have just been a slip of the tongue, with no bearing on other elements of his story. 

Quote
The best you can say on the Rosendahl commentary is
Why did HE raise the question about how any such knot
could play a roll (as does Giles)?!
--a fair point, that.
Except that one answer that springs to mind is that Cmdr.R.
was so knot-NOT-savvy that he simply had no clue, in such
matters : that hardly speaks to his having originated or
even insisted upon some particular, novel knot.
We can't really say anything on the Rosendahl commentary because it seems unavailable for review.  For all we know it could have been a letter from a relative of Rosendahl, and not Rosendahl himself.  If it was from Rosendahl himself, he may have been commenting on never hearing of a bend named after him even if the Rosendahl Bend was used (assuming he remembered it at the age of 84).  I could go on with hypotheses, but you get the drift on why these layers of hearsay makes this IGKT article ripe for retraction at the earliest convenience.

Quote
My weak surmise is that this Joe Collins did exist, and was
perhaps the orginator of the knot, but wanted to make a
*legend* for it (harkening to Tinker,Taylor,Soldier,Spy
concluding book Smiley's People reputed spy jargon
for getting a cover story for someone).
He was the originator, but didn't want to take credit for it and was willing to make up a whopper of a story?  Perhaps, but reckless scholarship shouldn't brand this guy a liar and a fraud.  The IGKT should retract the article, and work for better, verifiable facts.

Title: Re: Zeppelin Bend: Security and Strength
Post by: roo on January 30, 2012, 04:05:56 AM
   I repeat the (one) myth I proposed at reply#27, this time as a question :
Is it possible that Ashley was not aware of the Zeppelin bend, when he presents the same knot structure, as a stopper, at ABoK#582 ?
It's very possible, since it is very easy to overlook the relation between a single-strand lanyard knot and a similar bend structure.  Of course, the glaring omission in the section on bends is usually what makes people assume that the bend was either unknown to Ashley, or at least not well known to him at the time.
Title: Re: Zeppelin Bend: Security and Strength
Post by: Dan_Lehman on January 30, 2012, 04:24:10 AM
"Hearsay", you say?!  "so bad..." !!
--in contrast/competition to what, exactly, otherwise?
It's layers of hearsay on its own!  Where's the letter from Rosendahl that we can authenticate and verify for content?  We can't even produce the letter that refers to it!  THAT is bad... really bad.

As contrasted with producing a "Joe Collins"?!  And, frankly,
it is you making supposition about these documents being NA;
and making no such doubt about Collins being so --most biased
thinking.  (I'm pretty sure that the Wingfoot article is available,
and certainly Dr. Camplin who refers to it is, and has been asked
and so on.)  I don't know if Lee Payne might be yet with us.

Quote
At least in the Collins interview, the journalists are contacting someone with first-hand knowledge of the bend's use (assuming Joe's not making it up).  Joe could have been contacted at the time of the article for people who wanted to find out more.
Why do you insist that the Paynes are right in having bona fide
"Joe Collins", but dubious on having a Rosenthal letter?  I'll have
to dig back to where discussion led me to think that in fact they
did NOT contact JC, but that only one of them --viz., Bob-- recounted
what he'd heard told by JC.  (Count this as fuzzy recall (Dave Fred,
do you recall ... ?), pending discussion search.)

Quote
Quote
And if there is no record
otherwise about the supposed required special knot to do
some service (that a student of airship mooring cannot
conceive of!), that too raises questions --wouldn't a military
organization have made mimeographed tying instructions
issued to rope handlers so that they could learn the knot?
No, that trail is fruitless.  Every organization has tribal knowledge in some quarters that is not officially promulgated.

Not fruitless if something IS found!  And not so fruitless
if rather complete procedures are found that contain no
apparent *room* for such a knot's use.

Quote
Quote
And do you also think that Rosendahl and not Collins was
confused about where the alleged training occurred?
This is pointless on two counts:
1)  We cannot verify the contents of the missing Rosendahl letter.
2)  Even if Collins got this wrong, it could have just been a slip
of the tongue, with no bearing on other elements of his story.
If a real JC had never been to where the training actually
occurred, then he is shown false in his assertions.  He and
Rosenthal need to be together in some way that he could've
gotten from R. what R. (however) denies ever knowing.

Quote
Quote
The best you can say on the Rosendahl commentary is
Why did HE raise the question about how any such knot
could play a roll (as does Giles)?!
--a fair point, that.
Except that one answer that springs to mind is that Cmdr.R.
was so knot-NOT-savvy that he simply had no clue, in such
matters : that hardly speaks to his having originated or
even insisted upon some particular, novel knot.
We can't really say anything on the Rosendahl commentary because it seems unavailable for review.

It's as much available for review as is Joe Collins.

Quote
I could go on with hypotheses, but you get the drift ...
Indeed I do --you're barking at shadows.

Quote
Quote
My weak surmise is that this Joe Collins did exist, and was
perhaps the orginator of the knot, but wanted to make a
*legend* for it (harkening to Tinker,Taylor,Soldier,Spy
concluding book Smiley's People reputed spy jargon
for getting a cover story for someone).
He was the originator, but didn't want to take credit for it
and was willing to make up a whopper of a story?  Perhaps,
but reckless scholarship shouldn't brand this guy a liar and a fraud.
The IGKT should retract the article, and work for better, verifiable facts.

Ha, "retract the article", yeah, right.  The point of the "legend"
is to buy credentials for the knot --which "hey, look what I did!"
doesn't do (we can witness that regularly, here).  That's just a
surmise, hardly a "branding" at this point --but some scenarios
call for some basis, so there you go.  All that has been recently
done is to bring to awareness Lee Payne's footnote that says
Rosenthal denied knowing of any such knot, in balance to Lee
& Bob Payne's article saying that Joe Collins says that Rosenthal
insisted on some knot.  There's one degree of separation fewer
in the former claim than the latter, if you're counting "layers".


--dl*
====
Title: Re: Zeppelin Bend: Security and Strength
Post by: Dan_Lehman on January 30, 2012, 04:28:08 AM
Is it possible that Ashley was not aware of the Zeppelin bend, when he presents the same knot structure, as a stopper, at ABoK#582 ?
It's very possible, since it is very easy to overlook the relation between a single-strand lanyard knot and a similar bend structure.

+1.

One's particular *path* to a knot might have been
forged by an interest w/o  ends-joining in mind,
and the encounter made w/o time or interest or
energy to then explore the discovered structure
for all things that it might itself lead to if turned
inside-out and so on.  (Some cases of not realizing
things are more embarrassing than others.   ;) )

(-;
Title: Re: Zeppelin Bend: Security and Strength
Post by: xarax on January 30, 2012, 12:08:02 PM
   I repeat the (one) myth I proposed at reply#27, this time as a question :
Is it possible that Ashley was not aware of the Zeppelin bend, when he presents the same knot structure, as a stopper, at ABoK#582 ?
It's very possible, since it is very easy to overlook the relation between a single-strand lanyard knot and a similar bend structure. 

  1. Take any symmetric single strand knob knot. ( It can be a stopper knot, a lanyard knot, or a button knot. )
   2.  With a second rope, retrace the tail of this knot in its path inside the knot s nub, until half way to the standing end, i.e. until the centre of the knot. I call this retracing "semi-retracing". (Any suggestion for a more proper and descriptive name would be welcomed.)
   3.  Remove the first rope from the path that has been retraced by the second rope.
   4. You get a symmetric bend.
Title: Re: Zeppelin Bend: Security and Strength
Post by: roo on January 30, 2012, 06:19:39 PM
As contrasted with producing a "Joe Collins"?!  And, frankly,
it is you making supposition about these documents being NA;
and making no such doubt about Collins being so --most biased
thinking.  (I'm pretty sure that the Wingfoot article is available,
and certainly Dr. Camplin who refers to it is, and has been asked
and so on.)  I don't know if Lee Payne might be yet with us.
Joe Collins record in the Navy could at least be queried.  The time to ask for contact information for Joe would have been closer to the time of the article.

If the Rosendahl letter exists, I'm all for trotting it out word for word, to verify content, context, and authorship.  However, when trying to prove something, people usually lead with their best evidence.  What's the best evidence in the IGKT article?  A reference to a Wingfoot footnote instead of the Rosendahl letter that is two steps away from this footnote.

Quote
Why do you insist that the Paynes are right in having bona fide
"Joe Collins", but dubious on having a Rosenthal letter?  I'll have
to dig back to where discussion led me to think that in fact they
did NOT contact JC, but that only one of them --viz., Bob-- recounted
what he'd heard told by JC.  (Count this as fuzzy recall (Dave Fred,
do you recall ... ?), pending discussion search.)
If Bob Payne heard Joe Collins, how is that not contact?  I'm not insisting that Joe Collins story is beyond reproach, but this reproach needs to come from verifiable information, not from layers of unverifiable hearsay.

Quote
Not fruitless if something IS found!
I was referring to the fruitless endeavor of trying to prove a negative here.  Failing to find a record of the bend in official Naval record would prove nothing.  See what a difference a little context makes?  I think it's a long shot to find old Naval records of the bend, but if you think you can find such a record, go for it.

Quote
If a real JC had never been to where the training actually
occurred, then he is shown false in his assertions.  He and
Rosenthal need to be together in some way that he could've
gotten from R. what R. (however) denies ever knowing.
Proving this negative would have to be done with other avenues, such as contacting the US Navy (if they divulge such info).

Quote
--you're barking at shadows.
I have no problem barking at shadows when these unverifiable shadows are being used as a basis to defame the reputation of someone.  When you decide to call someone a liar based on unverifiable gossip, expect to get egg on your face.

Quote
Ha, "retract the article", yeah, right.  The point of the "legend"
is to buy credentials for the knot --which "hey, look what I did!"
doesn't do (we can witness that regularly, here).  That's just a
surmise, hardly a "branding" at this point --but some scenarios
call for some basis, so there you go.  All that has been recently
done is to bring to awareness Lee Payne's footnote that says
Rosenthal denied knowing of any such knot, in balance to Lee
& Bob Payne's article saying that Joe Collins says that Rosenthal
insisted on some knot.  There's one degree of separation fewer
in the former claim than the latter, if you're counting "layers".
Bringing "awareness" to unverifiable gossip that makes Joe Collins out to be a liar is completely irresponsible.  By the way, this wasn't Payne's footnote, it was a footnote in the Wingfoot Journal - another step away.

The time to verify any of these sources was some time ago if the best that can be had is a dead-end footnote that refers to a missing letter that refers to another missing letter that might have been written by a 84-year-old Rosendahl who may or may not have had a good memory of the events in question.   

If your cavalier attitude is common among the IGKT leadership, it doesn't make me want to rush out to pay them for their magazine.


Title: Re: Zeppelin Bend: Security and Strength
Post by: Dan_Lehman on January 30, 2012, 06:27:08 PM
It's very possible, since it is very easy to overlook the relation
between a single-strand lanyard knot and a similar bend structure. 
1. Take any symmetric single strand knob knot. ( It can be a stopper knot, a lanyard knot, or a button knot. )
2.  With a second rope, {}trace the tail of this knot in its path inside the knot s nub,
 until half way to the standing end, i.e. until the centre of the knot. I call this
{}tracing "semi-retracing".
(Any suggestion for a more proper and descriptive name would be welcomed.)
{hmmm, "reverse tracing" ?}
   3.  Remove the first rope from the path that has been {reverse-traced} by the second rope.
   4. You get a symmetric bend.

One needs to go a little farther than exactly halfway
--to have the overlap of to-become tails of the end-2-end knot.

So, an overhand stopper (though not symmetric in terms
of geometry, qua stopper) begets a ... nothing(!), a fig.8 stopper
a thief knot, and a symmetric fig.9 knot (#521) is also
a nothing (!).   .:.  This general scheme cannot be applied
generally with success, as promised; do not Pass GO.   ;)


--dl*
====
Title: Re: Zeppelin Bend: Security and Strength
Post by: Dan_Lehman on January 30, 2012, 08:40:07 PM
I have no problem barking at shadows when these unverifiable shadows
are being used as a basis to defame the reputation of someone.  When
you decide to call someone a liar based on unverifiable gossip,
expect to get egg on your face.
//
The time to verify any of these sources was some time ago ...
//
If your cavalier attitude is common ...

Verification in knotting is commonly lacking, on all things,
and counting "levels" as you do is a bit beside the point.
Bark at this, too, for whatever joy you take from it,
but it is what casts further doubt on the Boating article.
Again, this is from co-editor Lee Payne's now infamous footnote:
Quote
?The story was told to me [Lee Payne]
by my brother, who was sailing as second mate
aboard the President Madison.  Joe Collins was
the helmsman on his watch.  The fact remains
that this is an outstanding knot that is not listed
in any of the books on the subject.  Perhaps
some of your readers will recognize it."
To me, this says that the article was based on one
co-editor's recall of conversation had well prior.
(This could help explain the error in where training
occurred --Bob's recall, not Joe's.)

--dl*
====
Title: Re: Zeppelin Bend: Security and Strength
Post by: roo on January 30, 2012, 09:08:21 PM
For what it's worth, I did find a Joseph J.  Collins (ens.) in a 1918 Naval Directory, and a Joseph T. Collins (ens., instrn):

http://tinyurl.com/7r2jofe

If "instrn" indicates that he was an instructor, that would be consistent with the Payne account.   It may be him, but then again, Collins isn't exactly the rarest name, either.
Title: Re: Zeppelin Bend: Security and Strength
Post by: xarax on January 31, 2012, 02:49:00 AM
This general scheme cannot be applied generally with success, as promised; do not Pass GO.   ;)

   It is a "general" scheme, meaning it is a strategy that applies to many, indeed the majority of the cases. Discovering a handful of exceptions, ( as you always try to do... :)), especially if those exceptions are confined at the one end of the spectrum of the sample ( the most simple knots), does not mean that it does apply only to a few, "special" cases :) If it is not "special", it must be "general", is nt it that so ?
   Perhaps I use the term"general" wrongly... but, in general, a tossed coin will not stand on its end.  :) I could have easily passed the GO, if I had said the exact opposite, i.e. that a symmetric bend makes, with the reverse operation, a stopper. My point here was that the ABoK#582 is a knot with so similar a structure with the Zeppelin bend, that makes me wonder if/how Ashley knew the stopper, but missed the bend.
Title: Re: Zeppelin Bend: Security and Strength
Post by: erizo1 on February 29, 2012, 07:33:32 AM
I'm very new to knot tying. I'm interested in loops at the moment, and in the zeppelin loop in particular. We have xarax's opinion; I'm wondering what others think about the effect of loading one of the ends of the zeppelin bend in forming the loop. Does that make it a less-secure knot than the bend?

In my super-basic experiments, the zeppelin loop seems the most secure, meaning that it simply doesn't seem to move, whether I shake it or yank on it intermittently or whatever else. One way I've tested the stability of loop knots is by grabbing the loop on either side of the knot and pulling hard away from the knot (essentially a pull that would widen the loop). The zeppelin shifts a little and then stays put. The others I've looked at (bowline with or without a round-turn, Inuit bowline with or without a round turn, perfection loop) all deform much more than the zeppelin loop.

I'm also wondering how the zeppelin bend and loop compare in security to bends and loops typically used in rock climbing. Is there evidence to say definitively that the zeppelin bend and loop are or are not to be trusted with my life?
Title: Re: Zeppelin Bend: Security and Strength
Post by: Dan_Lehman on February 29, 2012, 07:46:07 AM
I'm very new to knot tying. I'm interested in loops at the moment, and in the zeppelin loop in particular. We have xarax's opinion; I'm wondering what others think about the effect of loading one of the ends of the zeppelin bend in forming the loop. Does that make it a less-secure knot than the bend?
I don't recall X. opining this, but simply that
the symmetry of the end-2-end knot's loading
is lost in the eye knot (as one overhand part
is loaded on both ends, the other not).

Quote
I'm also wondering how the zeppelin bend and loop compare in security
to bends and loops typically used in rock climbing.  Is there evidence to say definitively
that the zeppelin bend and loop are or are not to be trusted with my life?

Rockclimbers use end-2-end knots in just a couple of
cirucumstances : joining ends of a small line or tape
to form a closed-loop sling; joining abseil ropes together.
In neither of these cases would one have good reason
to favor the zeppelin bend.

Eye knots are used for tying in, and the zeppelin eye knot
will suffice, as will many many others.  Its ease of UNtying
after being loaded is one attractive aspect --but one shared
by numerous bowlines and other lesser known knots.

--dl*
====
Title: Re: Zeppelin Bend: Security and Strength
Post by: erizo1 on February 29, 2012, 03:58:22 PM
Dan_Lehman, I have a number of follow-up questions to your reply, but they go outside the topic of this thread. I'd be grateful is you'd reply to a new thread I started: http://igkt.net/sm/index.php?topic=3810.0.
Title: Re: Zeppelin Bend: Security and Strength
Post by: xarax on February 29, 2012, 04:41:45 PM
I don't recall X. opining this

As memory is helped by repetition, I will repeat the same things I have written in this forum MANY times ( but have been read only a FEW times, if any, I am afraid...), once again...See :
http://igkt.net/sm/index.php?topic=3810.msg22458#msg22458
Title: Re: Zeppelin Bend: Security and Strength
Post by: roo on February 29, 2012, 05:26:15 PM
... I'm wondering what others think about the effect of loading one of the ends of the zeppelin bend in forming the loop. Does that make it a less-secure knot than the bend?
Actually, the loop is more secure.  Just as the bowline is more secure than the parent sheet bend, most loop knots are more secure than their parent bend.  In a loop, one more part of rope is imparting tension into the knot form which usually keeps things more snug.  In some loops this may contribute to making the knot harder to untie, but in the Zeppelin Loop (http://notableknotindex.webs.com/zeppelinloop.html), ease of untying is maintained.

Quote
I'm also wondering how the zeppelin bend and loop compare in security to bends and loops typically used in rock climbing. Is there evidence to say definitively that the zeppelin bend and loop are or are not to be trusted with my life?
The Zeppelin Bend (http://notableknotindex.webs.com/Zeppelin.html) and Zeppelin Loop can be trusted with life.  In fact they or their double form would be my first choices.  And I've gotten positive feedback from people who use them in such capacity. 

The Zeppelin Loop is also quite nice in handling oddball loading configuration, such as accidental pulling of the free end, or loading the legs in opposite directions (the latter being something a Figure 8 Loop (http://notableknotindex.webs.com/figure8loop.html) can have problems with).  I also like the distinctive, symmetric knot form makes the Zeppelin Loop (and bend) very easy to check for errors, even from a distance.

I do think that the double/triple fisherman knots are the gold standard of security, it's just unfortunate that they're also horribly jam-prone.

The most important thing is that you are testing knots yourself in the material that you will be using.  There is no substitute for this.  It will give you a feel for the properties of knots that no amount of reading will do.
Title: Re: Zeppelin Bend: Security and Strength
Post by: erizo1 on February 29, 2012, 06:13:56 PM
Very grateful for the replies. Thanks!
Title: Re: Zeppelin Bend: Security and Strength
Post by: xarax on February 29, 2012, 06:57:48 PM
the bowline is more secure than the parent sheet bend

1. The Sheet bend IS NOT the parent of the bowline ! In fact, it has a very limited relation with the bowline, if any. Read the thread "What defines a bowline" (1), about what the bowline is...

2. I have seen no tests of the security or strength of any of the two forms of the Sheet bend, in comparison with any of the two forms of the bowline - tied with/on the same material. While this claim sounds reasonable, I would never trust another person s life on something that, although reasonable, is not tested experimentally.

1) http://igkt.net/sm/index.php?topic=3233.0

The Zeppelin bend and Zeppelin Loop can be trusted with life.

No, they can not, and they should not ! - until they are tested, and proven to be more secure and strong than any other similar knots that can possibly be used for the same purpose. Of course, I am speaking about other people s lives, ( OPL), because, if anybody actually believes in this, he can always put his own life into test - falling from a increasingly dangerous height above the ground.

I've gotten positive feedback from people who use them in such capacity.
I hope that the absence any negative feedback is not a consequence of a sufficiently dangerous height... :)

I also like the distinctive, symmetric knot form makes the Zeppelin Loop (and bend) very easy to check for errors, even from a distance.

   For the so-called "Zeppelin loop", such a distance is a prerequisite...The more the distance, the more 'distinct, symmetric form" this ugly monster acquires. At a sufficient distance, this tangle will be transformed into a perfect circle. However, as a knot, it always remains a zero.

Title: Re: Zeppelin Bend: Security and Strength
Post by: roo on February 29, 2012, 07:02:03 PM
1. The Sheet bend IS NOT the parent of the bowline ! In fact, it has a very limited relation with the bowline, if any.
:o :o :o :o :o

Lay a sheet bend besides a bowline and cover up all but the central knot form.  Notice anything?

Or tie a bowline and only load the standing part and the one leg belonging to the "U" shape.  Notice anything?

I probably shouldn't even bother responding to this. :-\
Title: Re: Zeppelin Bend: Security and Strength
Post by: xarax on February 29, 2012, 07:06:00 PM
1. The Sheet bend IS NOT the parent of the bowline ! In fact, it has a very limited relation with the bowline, if any.
:o :o :o :o :o

Lay a sheet bend besides a bowline and cover up all but the central knot form.  Notice anything?

I probably shouldn't even bother responding to this. :-\

I agree 100% !  :) You should not, because you do not understand that the Sheet bend has no nipping loop as the bowline...and you have not read the relevant thread in order to start trying to learn it.
Title: Re: Zeppelin Bend: Security and Strength
Post by: roo on February 29, 2012, 07:17:46 PM
the Sheet bend has no nipping loop as the bowline.
The loop or coil of the Sheet bend most certainly "nips" the U shape of the rope.  The distal part of the U shape helps anchor that coil so that it can provide nip.

Or would you like to claim that a bowline ceases to be a bowline as soon a rotating, high-friction load causes only the leg belonging to the U shape to be loaded?
Title: Re: Zeppelin Bend: Security and Strength
Post by: xarax on February 29, 2012, 07:34:02 PM
The loop or coil of the Sheet bend most certainly "nips" the U shape of the rope.  The distal part of the U shape helps anchor that coil so that it can provide nip.
Or would you like to claim that a bowline ceases to be a bowline as soon a rotating, high-friction load causes only the leg belonging to the U shape to be loaded?

   We have been talking about all those things, and then some, on the thread about bowlines (1). The question about the relation of the Sheet bend and the bowline, if any, has been discussed by an exchange of different views between Derek Smith and me. I have to remind you that you have vigorously insisted that this was not a "practical" matter, and you orchestrated the head to be removed from the "Practical knots" Forum, to the now extinct "Knot Theory"(!?) Forum..
  I would be glad if you have made up your mind by now, wish to read what was written there, and reply THERE.
( Many things "nip"other things, but they are not nipping loops !  :) )

1. http://igkt.net/sm/index.php?topic=3233.0
Title: Re: Zeppelin Bend: Security and Strength
Post by: roo on February 29, 2012, 07:39:07 PM
The loop or coil of the Sheet bend most certainly "nips" the U shape of the rope.  The distal part of the U shape helps anchor that coil so that it can provide nip.
Or would you like to claim that a bowline ceases to be a bowline as soon a rotating, high-friction load causes only the leg belonging to the U shape to be loaded?

   We have been talking about all those things, and then some, on the thread about bowlines (1).
I'm not going to sift through some protracted theoretical word fight to get an answer.   If you want to avoid the question, that is fine.  It's off topic, and you won't change your mind anyway.
Title: Re: Zeppelin Bend: Security and Strength
Post by: xarax on February 29, 2012, 07:46:03 PM
you won't change your mind anyway.

  Is this, at last, an admission by you that I, too, have a mind - as, presumably, you do? Thank you, doctor ! :)
Title: Re: Zeppelin Bend: Security and Strength
Post by: Dan_Lehman on February 29, 2012, 08:23:30 PM
the Sheet bend has no nipping loop as the bowline.
The loop or coil of the Sheet bend most certainly "nips" the U shape of the rope.
The distal part of the U shape helps anchor that coil so that it can provide nip.

It is more or less, resp., of opposite-side or same-side (recommended)
sheet bends, in that the mechanics of the "loop" here
are of loading-from-one-direction and not of both ends
(of the loop) being pulled upon (50% & 100%, with friction
leading to equalization at some point, in normal cordage).
One can suggest that the same-side ("proper") sheet bend
is just a tucked version of the thief knot , to put it in
perspective --of more nearly, in effect, U-2-U workings rather
than U-2-loop.  But this is getting awfully picky.

As for security and testing,
some arborist did test the zeppelin eyeknot in a kernmantle
("static", low-elongation something or other, 8-11mm, IIRC)
rope, and found it stronger than some fig.8 he also tested
("some" meaning that the exact orientation wasn't obvious).
It held to a high rupture value, so obviously didn't slip.
Meanwhile, we have the Dave Richards testing of various
kernmantle cordage (7mm accessory, 10.2? mm dynamic,
and 12.7mm low-elongation) to show that the sheet bends
(single & double) were weaker and less secure --sometimes
needing stopper knots!-- than bowlines.


Quote
Or would you like to claim that a bowline ceases to be a bowline
as soon a rotating, high-friction load causes only the leg belonging to the U shape to be loaded?

Well, this certainly points to issues in defining "knot",
and why I use ' *knot* ' often, to alert one to some
problematic definitions.  For, surely, in the loading above,
one has an effectively different physical structure and
should expect associated behavior if so!  And I do wonder
if by such effective loadings those trawler hawser bowlines
get capsized; the capsized forms are undeniable, but
the path TO them is unknown to me, up for inference.


--dl*
====
Title: Re: Zeppelin Bend: Security and Strength
Post by: xarax on February 29, 2012, 09:31:20 PM
...we have the Dave Richards testing of various kernmantle cordage (7mm accessory, 10.2? mm dynamic, and 12.7mm low-elongation) to show that the sheet bends (single & double) were weaker and less secure --sometimes
needing stopper knots!-- than bowlines.

Thanks for this information. Would it be too difficult for you to cite links ? 
 
  All those "tests" you refer to, are unique, once-happened phenomena ( should we better say "miracles" ? ), or they have been verified by reasonable repetition ? Because most of the 'knot tests" I read could not have attracted any attention, if done in any field of modern science and technology... ( And, yes, I know, middle ages were different in this requirement for "plenty" of numbers... :))

the path TO [the capsized forms of bowlines] is unknown to me

I believe we should first explore the ultimum strength of the many forms of "secure" bowline-like loops, before we would attempt to follow closely any - rare or not - collapse of those knots under extreme loading.