Author Topic: Zeppelin Loop and Double Dragon Loop - security based on experience  (Read 15850 times)

alanleeknots

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Re: Zeppelin Loop and Double Dragon Loop - security based on experience
« Reply #15 on: April 20, 2014, 06:45:17 AM »

   More photo here.

alanleeknots

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Re: Zeppelin Loop and Double Dragon Loop - security based on experience
« Reply #16 on: April 20, 2014, 06:49:25 AM »

   More photo here.

roo

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Re: Zeppelin Loop and Double Dragon Loop - security based on experience
« Reply #17 on: April 20, 2014, 04:27:31 PM »
 
      Hi All,

      We talk a lots about zeppeline loop here, when you have a over hand knot pulling 100% force by the standing part,
      in my mind the over hand knot bound to jam, it is not just a common sense? I am confuse.

      Any way I have a few simple load test here to share with everyone.

      This 7-16 inch nylon braid(very soft rope) the tensile strength may be around 3000 to 3500 lbs no so sure,
      I test it with 1/4 of it tensile strength, I found it can be untie with a lot of effort, when I top up another
      200 lbs. to 1000 lbs. now you need tool to untie it. and the rest of test just jam so bad, even with tool is very
      difficult to untie.

      謝謝  alan lee
Alan,

Have you considered that you're exceeding the working load limit of this rope?
 
3000lb / 5= 600 lb


 :o
« Last Edit: April 20, 2014, 04:29:36 PM by roo »
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xarax

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Re: Zeppelin Loop and Double Dragon Loop - security based on experience
« Reply #18 on: April 20, 2014, 05:57:59 PM »
   define : difficult to untie
   A knot is difficult to untie, if it is difficult to untie - provided that the rope on which it is tied is not loaded with more than the one fifth ( 1 / 5 ) of the load it can be loaded.
   
   define : jammed knot
   A jammed knot should NOT be considered "jammed", if the load under which it is jammed is greater than the one fifth ( 1 / 5 ) of the load it can be loaded.
   ( The new edition of Oxford Dictionary, with a new word for a-jammed-knot-when-the-load-under-which-it-jammed-exceeded-the-working-load-of-the-rope, is coming soon ).

  What one can learn in this Forum ! Not only new knots, but also new definitions about words describing knots ! A knotting thesaurus, indeed !  :)
  I propose a new section of the Forum, with the title : Knotting sense : New definitions of words about knots.
« Last Edit: April 20, 2014, 06:02:19 PM by xarax »
This is not a knot.

roo

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Re: Zeppelin Loop and Double Dragon Loop - security based on experience
« Reply #19 on: April 20, 2014, 09:55:28 PM »
...if the load under which it is jammed is greater than the one fifth ( 1 / 5 )...
Xarax,

If you want to break the first rule of ropework and disregard the safe working load limits of rope, that's up to you.  When the rope recoils after rupture and leaves a nice hole in your face, you'll have no one to blame but yourself.
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Dan_Lehman

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Re: Zeppelin Loop and Double Dragon Loop - security based on experience
« Reply #20 on: April 21, 2014, 08:59:53 PM »
   In Reply#20
   
http://igkt.net/sm/index.php?topic=4849.msg31804#msg31804

   I was joking about the attempt of a certain would-like-to-be knot tyer,
to deny the fact that the fake, so-called "Zeppelin" loop is more difficult to untie
than either the genuine Zeppelin knot, the Zeppelin bend, or any of the bowline-like loops,
that are not based on overhand knots or fig.8 knots tied on the Standing part.
To answer Alan's question, and redress this continued
opining, the "so-called" zeppelin eyeknot has been put
to some break tests and found to be, in the report of the
tester:
Quote
[ref. www.treebuzz.com/forum/threads/the-zeppelin-loop-vs-the-f8-in-pulls.15928/#post-228947
[ zeppelin vs. fig.8 eyeknots !
 There is also similar discussion of the end-2-end knot on this site. ]

Now we have a reliable and strong loop [eye] knot
that is super easy to take apart even after a huge load.
& also
the ZL is stronger and just as secure, if not more so
 than most bowlines and it's just as easy to untie.
(I didn't see the remark that he was able to untie
the survivor-of-2, but believe that that was the case.
--new forum format has fouled the quoting, alas (at
least as I viewed it w/local system).)
There is some "YMMV" per particular materials (his
I think was 9mm kernmantle rope, or similar); one
can figure that in HMPE things will be different, and
if the knot holds to break, that it will be jammed,
so much force *flowing* around ... . .

Alan, note that the overhand component is oriented
like a minimal timber hitch, and this is what gives
it chance to avoid jamming.

--dl*
====

xarax

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Re: Zeppelin Loop and Double Dragon Loop - security based on experience
« Reply #21 on: April 22, 2014, 12:37:55 AM »
the "so-called" zeppelin eyeknot has been put to some break tests and found to be, in the report of the tester :

  "In the report of the tester"(sic) ? ? ? I see this "conclusion" only as a reply to the report of the tester - a reply by some other author, who, I hope, is not you...  :)

Quote
[ref. www.treebuzz.com/forum/threads/the-zeppelin-loop-vs-the-f8-in-pulls.15928/#post-228947
[ zeppelin vs. fig.8 eyeknots ! ]
  Now we have a reliable and strong loop [eye] knot that is super easy to take apart even after a huge load. & also the ZL is stronger and just as secure, if not more so than most bowlines and it's just as easy to untie.

  First, as the title itself tells, the test was about the so-called "Zeppelin" loop, in comparison to the retraced fig. 8 loop - so irrelevant with was claimed by the cited "wise" pseudo-conclusion...
  Second, the test was about the strength of those knots, not about the easiness to untie them - which was not measured with any means. It is true that, to measure it, one would had needed some sophisticated laboratory instruments - but that does not mean that, in the absence of such instruments, one can say anything it happens to cross his mind !
  Third, "security" was examined in its narrow sense, as something that is related only to slippage. In fact, in the real world, in order to speak about security, in a broader sense, we should also take into account how easy is to tie or to untie a knot, because, in some dangerous situations, time can play a major role.
  Fourth, the "most" bowlines is a joke ! I am sure that the "wise" knot tyer, who replied in such a superficial way, does not know more than a small fraction of the bowline-like knots, and that he had tested not more than a small fraction of this fraction !
   In short, the above reply of what was really reported in the article by the tester, is but a wishful thinking of its author, and nothing more, I am afraid.
   
« Last Edit: April 22, 2014, 01:05:35 AM by xarax »
This is not a knot.

Dan_Lehman

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Re: Zeppelin Loop and Double Dragon Loop - security based on experience
« Reply #22 on: April 22, 2014, 07:14:49 PM »
the "so-called" zeppelin eyeknot has been put to some break tests and found to be, in the report of the tester :
//
& also the ZL is stronger and just as secure, if not more so than
most bowlines and it's just as easy to untie.

  "In the report of the tester"(sic) ? ? ?
I see this "conclusion" only as a reply to the report of the tester
--a reply by some other author, who, I hope, is not you...  :)
Touche' --as I whined, the visible '[ quote ] ' ... markers
instead of their intended effects made sorting out who
wrote what troublesome.
BUT, the 2nd quoted-by-me testimony to easy
untying of the zeppelin eyeknot IS from "Ron", tester.

Meanwhile, we can note differences in knots' behaviors:
Quote
After using it [zeppelin end-2-end knot on a tightline with a 5:1
it was fairly hard to untie but a trace 8 would've been welded.
//
[And elsewhere "Moray" reports breaking round-sling
"loops" in which 2 pieces of utility cord were joined
at both ends w/same knots --to ensure that there
would be a survivor knot--, and that the z. survivor
was "ridiculously easy to untie" !!  So, some *YMMV*.]


As for the remaining rabble, what more can be said?

Quote
  First, ... the cited "wise" pseudo-conclusion...
  Second, ... which was not measured with any means ... .
  Third, "security" ... .
  Fourth, the "most" bowlines is a joke ...., and nothing more, I am afraid.

While I won't dare hope to overcome the self-delusion
expressed above, I have yet hope that others will be
able to see clear, and so post these words here.


--dl*
====

alanleeknots

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Re: Zeppelin Loop and Double Dragon Loop - security based on experience
« Reply #23 on: April 23, 2014, 04:44:29 AM »

To answer Alan's question, and redress this continued
opining, the "so-called" zeppelin eyeknot has been put
to some break tests and found to be, in the report of the
tester:
Quote
[ref. www.treebuzz.com/forum/threads/the-zeppelin-loop-vs-the-f8-in-pulls.15928/#post-228947
[ zeppelin vs. fig.8 eyeknots !
 There is also similar discussion of the end-2-end knot on this site. ]

Now we have a reliable and strong loop [eye] knot
that is super easy to take apart even after a huge load.
& also
the ZL is stronger and just as secure, if not more so
 than most bowlines and it's just as easy to untie.
(I didn't see the remark that he was able to untie
the survivor-of-2, but believe that that was the case.
--new forum format has fouled the quoting, alas (at
least as I viewed it w/local system).)
There is some "YMMV" per particular materials (his
I think was 9mm kernmantle rope, or similar); one
can figure that in HMPE things will be different, and
if the knot holds to break, that it will be jammed,
so much force *flowing* around ... . .

Alan, note that the overhand component is oriented
like a minimal timber hitch, and this is what gives
it chance to avoid jamming.

--dl*

Hi All,
     
      Dan I don't quite follow what you trying to said here. but my nose is quiet sensitive, I felt guilty of my nose.
      I smell something I shouldn't have to, your body release someone else's perfume. I don't like it.

      I like this popular chinese phrase 真的假不了 假的真不了 I use google to translate
      = Reality Bites can not really fake

      Tomorrow I will post the rest of the test as Roo request

      謝謝  alan lee

roo

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Re: Zeppelin Loop and Double Dragon Loop - security based on experience
« Reply #24 on: April 23, 2014, 05:44:15 AM »
      Tomorrow I will post the rest of the test as Roo request

      謝謝  alan lee
I don't recall this request.  Maybe you're thinking of someone else.
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alanleeknots

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Re: Zeppelin Loop and Double Dragon Loop - security based on experience
« Reply #25 on: April 23, 2014, 06:27:57 AM »
    Hi All,

       Roo,this is how you reply on reply #17 (Alan, Have you considered that you're exceeding the working load
       limit of this rope? 3000 lb / 5= 600 lb),so realise my way is wrong, you way is the standard way,
       and I automatically think I should do the test right way,
       due to my poor English, I misunderstand it, I am sorry.

       Since I already got it tested, I think some of reader may like to see it, what to you think should I post it?

       謝謝 alan lee
« Last Edit: April 23, 2014, 06:34:42 AM by eric22 »

xarax

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Re: Zeppelin Loop and Double Dragon Loop - security based on experience
« Reply #26 on: April 23, 2014, 12:59:12 PM »
I realised that  my way is wrong, your way is the standard way,

  There is NO "standard way" to test and measure the easiness or difficulty we can untie a knot ! AND, as I have mentioned many times, there is no "way", even considered as "best practice", other than just puling and pushing, bending two different parts of the knot s nub relatively to each other, etc.- i.e., some manipulation of the knotted rope we are not able to quantify or measure.
  To take the various values of the "working" load of a rope, suggested by various organizations for various occupations and activities using ropes, and mis-use them as limits under which we should examine if a knot is easy to untie or not, is a <edited, by me... :)>. I have seen "working loads" ranging from the 1 / 4 to the 1 / 15 of the MTB... There are many situations where the ropes and the knots happen to be loaded, accidentally or on purpose, with loads approaching their MTB, so far beyond the recommended "working load" - and in those situations the need for an easy-to-be-untied knot may be even greater than in normal, everyday situations. To suggest that, iff a knot can be untied iff it is loaded with the 1 / 5 th of the MTB, it would be OK, is a DANGEROUS thing to do ! It reveals a total ignorance of what is happening in "dynamic" loading, or accidental loading, with loads far greater than those we had anticipated.
   Of course, this stupid idea was nothing but an ad hoc pseudo-invention of somebody who tried to saved a mediocre knot that has been occupying his brain cavity ( of unknown volume ) from time immemorial. I had only COMPARED the difficulty to untie this knot, with the easiness to untie the Zeppelin knot, or the bowline-like, PET knots. ( I have no sufficient experience with the Double Dragon knot to have an opinion - I have tied it only a few times, and, until recently, I had confused it with another "similar" knot !  :)).   
   In boating, for example, one is confronted with such situations all the time ! Suddenly the mooring or the anchor line of another boat is entangled to yours, and both boats start moving towards a third one !  :) In general, one is seldom able to predict what will really happen in a outdoor activity - and ANY limits put on the "working" loading in advance will not help a jammed knot get untied !
   It is true that we should better quantify the mostly subjective quality we describe as "easiness to untie", and one way would be to specify the different loads and loading patterns under which a jamming of a knot can occur. Some time ago I had proposed to sort the knots in five categories, defined by the maximal loading under which the knot can still be untied easily - whatever we decide that will mean. The 1 / 4, 1 / 3, 1 / 2, 2 / 3, 3 / 4  of the MTB  of the rope ( to keep the ratios simple enough, and to compare the limit of the "easiness" according to a quantity/value/number of the rope, not of the knot ).
   I am sure that almost ALL knots would be easy to untie, if the "working" load of the rope is sufficiently small, compare to its MTB... I imagine that NASA, for the space walk tethers connecting the astronaut with the space vehicle, uses "working loads" of 1 / 100 - under such "working loads", I am sure that there is not ANY knot, even worse than the fake, so-called "Zeppelin loop", which will NOT be "easy to untie" - so, why should we bother to measure it ? 
   Of course, another thing we have to consider is the softness or the stiffness of the rope. When we claim that a knot is "easy to untie", we do NOT mean that it is "easy-to-untie-iff-it-is-tied-on-boiled-spaghetti" !  :) ANY knot can be untied easily, if it is tied on a soft enough rope ! AND, if the rope is veeery soft, any knot can be untied by itself, without us !  :) So, when we say that a knot is "easy to untie", we mean "it is easy to untie if tied on whatever rope" - provided this rope is not made from Velcro !  :) So, the < edited, by me > idea, that we can claim a knot is "easy to untie" when it is easy to untie iff it is tied on soft enough ropes, is < edited, by me >.
   A knot tyer ( actual, or would-like-to-be, it does not matter...) wants to make some $ ( dollars ) from a site ( pathetic or not, it does not matter ) of his - and he sell commercials, which are paid according to the number of clicks / visitors of the site. That is not sooo stupid - people visit much-much more pathetic sites, and even pay for their visits to them ! However, when he USES a public Forum, like this, to advertise his own site, over and over again ( in almost ANY thread, he inserts references to the same pages of his web-site, again and again...) , that is starting to smell badly. And when he starts "INVENTING" new meanings, by twisting the meaning of words already in use by everybody, THAT is worse... AND when his pseudo-inventions are referring to SECURITY, and he claims that a knot is easy to untie, even iff it is only "easy to untie when loaded by the working load", THAT is dangerous ! When he will discover that in some other uses of ropes there are recommendations of "working loads" even smaller than the 1 / 5 th of the MTB ( like the 1 / 100 ? in space walking ... :)), he will baptise each and every pathetic knot as "easy to untie", and secure ! And he will be able to gain more $ by this !
   I am not sympathetic to the vagrant knot sellers, not because of the occupation, but because of the low quality of their merchandise : most knotting sites and books are ruminating the same knotting myths - and, as we have seen, some of them are even producing new ones ! ( However, I am sympathetic to the difficulty of people, like Dan Lehman, who feel they have to defend them, somehow...  :)) This new myth, that a knot is easy to untie even if it is easy to untie only when loaded by a fraction of the MTB ( fraction not specified, as the "working load" in the various activities involving ropes vary...), is DANGEROUS - because security, in the broad sense, is related not only to slippage of a knot, but to the easiness of tying and untying it as well.
   As I had said many times, the difficulty of untie-ness is only the last from a long series of disadvantages of the fake, so-called "Zeppelin loop". I will not repeat them here - the interested reader can "search" the words : fake, so-called, "Zeppelin loop", and read - BUT, what is FAR better, he can TIE this mediocre eyeknot, load it, and SEE for himself. Then, if he still wishes to buy whatever knot-sellers sell, he will have no one to blame except himself.
« Last Edit: April 23, 2014, 01:59:52 PM by xarax »
This is not a knot.

Dan_Lehman

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Re: Zeppelin Loop and Double Dragon Loop - security based on experience
« Reply #27 on: April 23, 2014, 04:38:43 PM »
Quote
To answer Alan's question, ...

the ZL is stronger and just as secure, if not more so
 than most bowlines and it's just as easy to untie.

...
Alan, note that the overhand component is oriented
like a minimal timber hitch, and this is what gives
it chance to avoid jamming.

--dl*
     
Dan I don't quite follow what you trying to said here.
but my nose is quiet sensitive, I felt guilty of my nose.
I smell something I shouldn't have to, your body
release someone else's perfume.  I don't like it.

Alan, try reading with your eyes --if your nose
is hitting the screen, you're too close to it!   ;D
What I said is quite simple : you thought that
any overhand in a knot must make it jam,
and I found evidence to the contrary --where someone
had tested the "zeppelin loop" to high forces (i.p.,
to where a fig.8 eyeknot on the opposite end of the
test specimen had broken) concluded that it was easy
to untie.

--dl*
====
« Last Edit: April 23, 2014, 05:18:21 PM by Dan_Lehman »

Dan_Lehman

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Re: Zeppelin Loop and Double Dragon Loop - security based on experience
« Reply #28 on: April 23, 2014, 05:17:25 PM »
   NOWHERE did "Ron", the tester, said ANYTHING about the ...
 "Zeppelin" loop being "easy to untie" ! The quotation in his second post,
is simply a quotation of the reply to his first post
...  Read the SMALL print, with capital letters : "QUOTE".
So, next time, when you make such a understandable mistake,
as we all do from time to time, do not try to cover it up in your reply...
X., you're deep in the manure pit now, and
it's best to put a lid on that --and you, if you
that's where you prefer to stay.

Others, where is YOUR reply to this BS?
The cited reference is after all readable by all,
and it clearly says :
Quote
...
[ QUOTE ] #1
[ QUOTE ] #2
Now we have a reliable and strong loop knot that is super easy to take apart even after a huge load.

[/ QUOTE ] #2-close
!? But there is already quite a set of Bowlines for that -- old technology, complemented with various methods to secure the knot.

[/ QUOTE ] #1-close
[& here, RON's --the tester-- commentary]
The ZL is stronger or as strong as an F8 and can be untied much easier.
The ZL is stronger and just as secure, if not more so, than most bowlines
and it's just as easy to untie.
...

I hope that all unbiased readers can comprehend this.
In other cases, though ...
Quote
Poor Ron, he made some pathetic kitchen-located tests,
on three ( THREE ! ) samples, he does not even report all the other details
of the experiments as he should had done, and, suddenly, he has fans,
and he became a wise "tester" we should respect !  :)
.
.
.
There is NOTHING in the post you cited that tells something about the easiness of untying,
neither the absolute one, nor the relative one ( = comparatively to ANY bowline,
.
.
.
Poor Dan Lehman, he reads the quotes of the replier to the tester as quotes of the tester himself

Again, with the lamentable BS from one who
has done nothing but whine about what others
have or have not done when whichever does not
serve to support his claims!  EStar did not do good
enough testing on the entire spectrum of knottable
materials and all possible knots ...,
and Ron did only "pathetic kitchen tests" (funny how
this someone's own kitchen cannot produce even such
tests!), and yet he broke ropes and was able to see
that the "zeppelin loop" was able to be untied, easily,
in the kernmantle rope he used.


 >:(

xarax

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What an interesting test! I pulled an F8 against an F8 tied in PMI 9mm (I had formerly posted 10mm; it was in fact 9mm)EzBend to get a baseline and one of the F8s failed at 3465 lbs. I think that's a bit low, but....

 This is the version of the Zeppelin loop I tested:

[​IMG]{ See the attached picture }

 I then pulled a ZL (Zeppelin loop) against an F8 loop and the ZL failed at, 3601 lbs. I told you that F8 vs F8 seemed a bit low!

 I repeated the test - new rope and knots of course, and guess what? The F8 failed at 3397 lbs!

 I repeated the test a third time and the F8 failed at 3536 lbs!

 So in summary:

 1- F8 vs F8 - failure at 3465 lbs
 2- F8 vs ZL - ZL failed at 3601 lbs
 3- F8 vs ZL - F8 failed at 3397 lbs (notice how close that failure is to the F8 vs F8)
 4- F8 vs ZL - F8 failed at 3536 lbs


Ron, May 24, 2010
« Last Edit: April 23, 2014, 07:06:17 PM by xarax »
This is not a knot.