International Guild of Knot Tyers Forum

General => Practical Knots => Topic started by: Festy on June 02, 2014, 06:52:39 PM

Title: Double Dragon Loop trumps the Bowline Family?
Post by: Festy on June 02, 2014, 06:52:39 PM
That is my query.

The DDL is easy to tie, is easy to remember, and is a safe knot (or so it seems to this amateur knotter).

There is no multitude of ways to tie it, lock it and whatnot like there is with the bowline.

So, for someone who just wants to remember how to tie enough knot types to get by, is the DDL a good way to go?

cheers

Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: roo on June 02, 2014, 07:33:03 PM
That is my query.

The DDL is easy to tie, is easy to remember, and is a safe knot (or so it seems to this amateur knotter).

There is no multitude of ways to tie it, lock it and whatnot like there is with the bowline.

So, for someone who just wants to remember how to tie enough knot types to get by, is the DDL a good way to go?

cheers
There are a few ways of tying the double dragon loop, but the simple way has a fundamental problem in that you cannot thread the rope around or through an object before closing.  That's somewhat important for an end loop. 

The loop isn't suitable for on-the-bight use as it can jam in that configuration unless one side of the parent line is unloaded.

In stiffer rope, the security of the double dragon isn't as much as one would expect from a loop with such complexity.  A water bowline does better:

http://notableknotindex.webs.com/waterbowline.html
Update:  related: http://notableknotindex.webs.com/monsoonbowline.html

The double dragon loop also has some problems with stability when the two legs of the loop are pulled in opposite directions.
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: Festy on June 02, 2014, 08:13:31 PM

There are a few ways of tying the double dragon loop, but the simple way has a fundamental problem in that you cannot thread the rope around or through an object before closing.  That's somewhat important for an end loop. 



http://www.southee.com/Knots/Knots_SingleLoops.htm

see no. 5, Method #2

Maybe I'm wrong, but this seems to do what you describe above?

Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: roo on June 02, 2014, 08:53:57 PM

There are a few ways of tying the double dragon loop, but the simple way has a fundamental problem in that you cannot thread the rope around or through an object before closing.  That's somewhat important for an end loop. 



http://www.southee.com/Knots/Knots_SingleLoops.htm

see no. 5, Method #2

Maybe I'm wrong, but this seems to do what you describe above?
That's why I specified the "simple" method.  The alternate method is very prone to misremembering and error.
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: Festy on June 02, 2014, 09:02:40 PM
That's why I specified the "simple" method.  The alternate method is very prone to misremembering and error.

copy that
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: xarax on June 02, 2014, 09:11:21 PM
   The Double Dragon is a fine loop - provided it is double ! :) I mean, it is the doubled version of the Tugboat A loop, shown at :
   http://daveroot.atspace.cc/knots/Knots_SingleLoops.htm#PerfectionLoop
   http://daveroot.atspace.cc/knots/Knots_SingleLoops.htm#DoubleDragon
   The main problem with the single version, the Tugboat A, is that the positions of the continuations of the eye legs may be swapped inside the nipping loop, resulting in an unstable knot, which can be severely deformed under heavy loading. I say " they may be swapped", because/although this had never happened to the few, only, Tugboat A loops I had tied and tried in my life - but as it can happen, I have to suppose that, eventually, obeying Murphy s Law, it will happen...
   The "doubled" version is supposed to address this problem, because the nub of the Double Dragon s eye-knot is more voluminous, spherical and compact than the nub of the Tugboat A, and the positions of the corresponding segments of the rope inside it are now more stable : they can not swap positions very easily. Also, the second wrap of the collar structure keeps the nipping structure "closed", and, with the help of the friction and the stiffness of the rope, it retains its integrity and prevents any severe deformation. However, the problem of the two possible dressing forms, of which the one is much better, stable and good-looking than the other, remains - in theory, at least, the knot can be either dressed or settle in the "wrong"/ "inferior"/ "ugly" form - and, although in the doubled, dragon version, due to the presence of the second wrap, this will not lead to a catastrophic deformation, in my mind it is a point of concern nevertheless. It is not just a "bistable knot" ; it is a knot where the one "stable" form is based on a nipping structure which is depending upon the services offered by the collar structure too much - so, in theory, at least, it is a knot where the one stable form is much less stable than the other !  :)
   Moreover, as it happens to many of the TIB crossing knot-based eye-knots (1), the nipping loop forms a tight collar around the eye legs, and that is a disadvantage regarding ring loading.
   Another possible disadvantage, regarding strength, is that the Standing Part s first curve is narrow, because it encircles the two eye-legs only, so two, only, rope diameters.
   However, what bothers me more is that it is a doubled version of something that is not good enough as a single... I would had preferred a doubling that would duplicate something already very good !  :)

1.  http://igkt.net/sm/index.php?topic=4354.0
     http://igkt.net/sm/index.php?topic=4354.msg29708#msg29708
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: Dan_Lehman on June 03, 2014, 06:17:36 PM
   The Double Dragon is a fine loop - provided it is double ! :) I mean, it is the doubled version of the Tugboat A loop, shown at :
...
what bothers me more is that it is a doubled version of something that is not good enough as a single... I would had preferred a doubling that would duplicate something already very good !  :)

Were the tail to go in the opposite direction in
its wrappings, you do get something better in
the single version, which can be dressed and
set to have an appealing-looking gradual curve
of the SPart (to what extent this has actual
practical benefit, we don't know --though I think
it does help keep the knot more easily untied).

I found this knot in the Wild some years ago
at Cape May Point; beyond the find, I had no
further information about its use / user.
(The tail is (un)raveling as it exits rightwards.)


--dl*
====
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: xarax on June 03, 2014, 09:02:58 PM
I found this knot in the Wild some years ago at Cape May Point;

  It looks like the Tugboat B to me...
  http://igkt.net/sm/index.php?topic=112.0

  The deflexion of the Standing Part  before its first curve is significant, indeed. Moreover, the swap of the eye legs into the "lower collar" seems less possible ( the one path of the returning eye leg towards the "higher collar" is much straighter and shorter than the other ), and, even if it does take place, it leads to an equally stable eye-knot.
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: xarax on June 04, 2014, 04:04:49 AM
  The "reversed" eyeknot of the Tugboat B loop  ( i.e., a "transformed" eye-knot, where the Standing + Tail Ends pair and the eyelegs pair of the initial one have been swapped ), is shown at (1), and at the attached pictures. As a reversed form of a TIB eyeknot, this eye-knot is also a TIB eye-knot - although, by this transformation, the initial TIB crossing-knot Tugboat B loop is now turned into a (secure/locked) TIB bowline ( as simple as the Lehman s TIB bowline).
   As I had mentioned at (1), the doubled version of this TIB bowline is identical to a modification, by JP, of the ( already modified initial one :) ) Tresse bowline, tied by Alpineer (2). So, to compare apples to apples, the interested reader should compare the Double Dragon to the "reversed" TIB Tresse bowline. Good luck !  :)

1. http://igkt.net/sm/index.php?topic=4695.msg30330#msg30330
2. http://igkt.net/sm/index.php?topic=4595.0
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: xarax on June 04, 2014, 04:06:38 PM
   I seize the opportunity to illustrate the similarities between the "correctly dressed" forms of those two eye-knots : the reversed Tugboat A loop and the Samisen 4 bowline ( shown at (1)). As one might have expected, the "wrongly dressed" forms of those eye-knots suffer from the same problem, to the same degree : their unbalanced nipping structures may "open up" and disintegrate, if their eyelegs are loaded in a certain uneven and unfavourable way. 
   I had noticed that this deceivingly compact and good-looking Samisen 4 bowline :

can also be dressed in a more unstable form than the shown one, which might be considered as a serious disadvantage
 
 , but I had not realized, till now, that ( as I should had expected...), the cause of the problem is the similarity of its form to the form of the reversed Tugboat A bowline ( which also suffers from the same problem ).
   
1.  http://igkt.net/sm/index.php?topic=4883.msg31900#msg31900
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: Festy on June 05, 2014, 06:50:49 PM
Can we say that the Yosemite bowline is more secure than the Standard bowline?
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: xarax on June 05, 2014, 08:09:15 PM
   Can we say that the Yosemite bowline is more secure than the Standard bowline ?

   Yes, because a more complex knot can not be less secure than a simpler one. 
   No, because we are not allowed to ask this question in the first place : we should always compare apples to apples.
   { The Yosemite bowline is a "secure" bowline, a two-collar ( = double collar ) bowline, which is a much more complex knot than the "Standard" bowline. Perhaps we can say that one of the four "Eskimo" bowlines is more secure than one of the two "Standard" bowlines, or that the Lee s locked bowline is more secure than the Yosemite bowline(*), because we can compare eye-knots which belong to the same family, regarding complexity.}

   So, there are two ends in this new line of yours - but I believe you should better stretch it as a new thread...

 (*) As mentioned by Mark Gommers in the Analysis of Bowlines : "The "Yosemite" bowline can easily be miss-tied. If the tail is drawn up before the SPart has been tightened (hence also tightening the nipping turn), the tail can be displaced to the extent that the entire bowline structure is compromised." The Lee s locked bowline does not suffer from this.
 
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: Dan_Lehman on June 05, 2014, 09:25:45 PM
   Can we say that the Yosemite bowline is more secure than the Standard bowline ?

   Yes, because a more complex knot can not be less secure than a simpler one.
Perhaps this should be better restated as
the extension of a knot cannot be less secure
than the (base) knot itself
--although even here,
one might want to be more circumspect!

In tests of abseil-ropes-joints, the offset water knot
(aka "EDK"="Euro Death Knot" ) proves more secure
under load than the "more complex" offset figure 8 bend
--with the irony that the latter might have been chosen
presuming just the opposite.


--dl*
====
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: xarax on June 05, 2014, 09:59:20 PM
the offset water knot (aka "EDK"="Euro Death Knot" ) proves more secure under load than the "more complex" offset figure 8 bend

  Good find ! If "security" here is not meant as anything more than just resistance to slippage, this should be the only exception that proves the rule !  :)
  Perhaps the gripping power of the nub on the Tails is "wasted" along the longer and more convoluted paths of the Stranding parts, so the generated friction is distributed and consumed in places it is not needed...  :-\ :-\ :-\
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: Festy on June 06, 2014, 11:18:23 AM

   Yes, because a more complex knot can not be less secure than a simpler one. 
   No, because we are not allowed to ask this question in the first place : we should always compare apples to apples.
   { The Yosemite bowline is a "secure" bowline, a two-collar ( = double collar ) bowline, which is a much more complex knot than the "Standard" bowline. Perhaps we can say that one of the four "Eskimo" bowlines is more secure than one of the two "Standard" bowlines, or that the Lee s locked bowline is more secure than the Yosemite bowline(*), because we can compare eye-knots which belong to the same family, regarding complexity.}

   So, there are two ends in this new line of yours - but I believe you should better stretch it as a new thread...

 (*) As mentioned by Mark Gommers in the Analysis of Bowlines : "The "Yosemite" bowline can easily be miss-tied. If the tail is drawn up before the SPart has been tightened (hence also tightening the nipping turn), the tail can be displaced to the extent that the entire bowline structure is compromised." The Lee s locked bowline does not suffer from this.

and the Lee's lock is the Yosemite with the bitter end fed back down through the two collars?

now the line in red has me puzzled I must say!

Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: xarax on June 06, 2014, 01:54:06 PM
the Lee's lock is the Yosemite with the bitter end fed back down through the two collars ?

Precisely.

now the line in red has me puzzled I must say !

   The Yosemote and the Lee s locked bowlines are "secure" bowlines, and, although the later is a little ( one tuck ) more complex than the former, both belong to the same class regarding complexity, IMHO. They can not be compared to the "Standard" bowline, which - as we should never forget - is still the King of knots !  :) A superb knot is not just a more secure knot : it is a knot where security, strength, easiness of memorizing, tying and untying, structural simplicity and visual beauty, all those are in the right proportion to each other, in harmony. This is a marvellous event, that happens most rarely - and when it happens, it generates those peaks of the mountains we see in the KnotLand, which we are allowed to admire, but not compare ! The "Standard" bowline is such a peak, I would nt dare to compare it with any other eye-knot...

Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: xarax on June 06, 2014, 02:07:57 PM
   The two "wrongly dressed" forms of the reversed Tugboat A ( Single Dragon ) and the Samisen 4 bowlines. We can see that the former/left is a "normal" bowline, while the later/right is a crossing-knot based one. If their "right" leg of the eye is loaded more than the 'left", their similar nipping structures will "open up", and be deformed badly. The ABoK#1051 "Eskimo"-like, ( also TIB ) bowline, which is the "reversed" ( in the other sense !  :)) of the reversed Tugboat A  bowline, suffers from the same problem.
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: Festy on June 08, 2014, 06:21:41 PM


   The Yosemote and the Lee s locked bowlines are "secure" bowlines, and, although the later is a little ( one tuck ) more complex than the former, both belong to the same class regarding complexity, IMHO. They can not be compared to the "Standard" bowline, which - as we should never forget - is still the King of knots !  :) A superb knot is not just a more secure knot : it is a knot where security, strength, easiness of memorizing, tying and untying, structural simplicity and visual beauty, all those are in the right proportion to each other, in harmony. This is a marvellous event, that happens most rarely - and when it happens, it generates those peaks of the mountains we see in the KnotLand, which we are allowed to admire, but not compare ! The "Standard" bowline is such a peak, I would nt dare to compare it with any other eye-knot...

Glad to hear that the Yosemite bowline is classified as secure, I must say I like the Yosemite knot.
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: xarax on June 09, 2014, 02:38:23 AM
Glad to hear that the Yosemite bowline is classified as secure

  I believe I made it clear that "security" was meant here as a quantity-fier ( in relation to the degree of the complexity of the knot ), not as a quality-fier. The quality of the Yosemite bowline as a "secure" bowline was not examined. As  I see it, Lee s locked bowline, for instance, is a much better eyeknot.
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: Festy on June 10, 2014, 09:41:07 PM


  I believe I made it clear that "security" was meant here as a quantity-fier ( in relation to the degree of the complexity of the knot ), not as a quality-fier. The quality of the Yosemite bowline as a "secure" bowline was not examined. As  I see it, Lee s locked bowline, for instance, is a much better eyeknot.

would the DD then, be a secure knot, quality wise?
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: xarax on June 11, 2014, 01:36:44 AM
would the DD then, be a secure knot, quality wise ?

  Taking into account that it is a TIB knot, I believe that yes, it is - although I should repeat that I have a limited, only, experience of using it. ( You should better ask Knot4u, he has said that he uses it all the time ). However, that does not mean that I answer the initial question of this thread in the affirmative : to my view / taste, and for the time being, I think that the Ampersand bowline or the pet loop are "better"( :) ) eye-knots.
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: Festy on June 11, 2014, 05:45:32 PM


  Taking into account that it is a TIB knot, I believe that yes, it is - although I should repeat that I have a limited, only, experience of using it. ( You should better ask Knot4u, he has said that he uses it all the time ). However, that does not mean that I answer the initial question of this thread in the affirmative : to my view / taste, and for the time being, I think that the Ampersand bowline or the pet loop are "better"( :) ) eye-knots.

Is there a demo of the Ampersand and the Pet Loop anywhere? I've searched on Youtube but no luck!
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: xarax on June 11, 2014, 07:52:27 PM
   Festy, the mother of all knots is THIS Forum !  :) Search here !

   For the Ampersand bowline :
   http://igkt.net/sm/index.php?topic=4877.msg31923#msg31923
   http://igkt.net/sm/index.php?topic=4877.msg31929#msg31929

   For the pet loop :
   http://igkt.net/sm/index.php?topic=4354.msg27824#msg27824
   http://igkt.net/sm/index.php?topic=4354.msg27855#msg27855
   http://igkt.net/sm/index.php?topic=4354.msg27856#msg27856

   If there is something still unclear there, please, tell me and I will see if / how I can correct it. Also, I have to stress that, in those posts, I describe one, only, of the many tying recipes you may use to tie those knots in-the-bight- there may well be many others, which are waiting for you to discover and describe them to us here.
   You may also wish to post your own video on the tying of those eye-knots in YouTube. In the KnotLand, as in any of the experiences we get from life, paths are made by walking. Reading the posts in this Forum, or remembering the posts you have already read ( and even commented on ), may also help a little bid... :)
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: Festy on June 11, 2014, 08:44:07 PM
   Festy, the mother of all knots is THIS Forum !  :) Search here !

 

ha, ha, very good Xarax.

however, Thomas should be my middle name, unless I can see it happening in realtime I'm in trouble (unless it's a simple knot)  :D
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: xarax on June 11, 2014, 10:58:17 PM
unless it's a simple knot

  "Simplicity" is a complex thing - and that is true for knots, too. Mathew Walker 2-stand bend looks like a pretty "simple" knot, but it is difficult to dress correctly. The falsely tied Zeppelin bend is more symmetric, so more "simple", than the Zeppelin bend, yet it is a lousy knot, for reason we do not quite understand. The Tumbling Thief knot is the most "simple" bend possible, but the way it works is difficult to analyse, so there is a discrepancy between the "feeling" of security it conveys and the actual security it delivers. On the other hand, a retraced stopper turned into a bend ( as the fig.8 knot, for instance ) is "complex" in topology and appearance, yet it is easy to tie, because all one has to do is to make the Working End of the second link follow the Standing Part of the first link.
   Also, what seems "simple" to one person, may not look so simple to another. The tying methods of the Ampersand bowline and the pet loop seem pretty simple to me now, but perhaps that is due to my recent understanding of the working of those knots, which did not come without some previous preparation, on other, similar knots. The "haltered collar" method of inserting the Standing and the Tail Ends into a collar looks like a very easy thing, but it was not understood, or appreciated, by me, until I had applied it many times, in many other knots. The "three bights" method of tying the pet loop was implemented in ABoK many times, but I had not realized how productive it was until I had tied many TIP loops following it. So, "simplicity" needs time to reveal itself - but when it does, man, it is a most beautiful sight one can watch, which he can/will never forget.
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: agent_smith on June 21, 2014, 02:47:52 PM
Quote
Glad to hear that the Yosemite bowline is classified as secure, I must say I like the Yosemite knot.

One could surmise that the ultimate test of 'security' is literally putting your life-on-the-line (as I do when I go mountaineering or rock climbing at my local crag) and be willing to take a free-fall (and repeated free-falls in quick succession). I suppose if you live and can walk-away unharmed, that might be evidence of the knots performance! If you die, I guess that might be evidence to the contrary. Note: This is my attempt at poorly conceived dark humor.

The are only a select few knots that I'm willing to use as a 'tie-in' directly to my harness (that is, the rope is tied directly into the harness - a soft interface - no metal links present).

I have used the Yosemite Bowline but, as Xarax points out, it can easily be disturbed by prematurely pulling on the tail before the nipping turn has been drawn tight. Furthermore, somewhat stiffer ropes may not be an ideal material for this Bowline variant. You need to assess the knot after tying it and make a judgement call on its 'security'.

A 'strangled double overhand knot' can be added to the Yosemite Bowline as 'insurance' - which is to say that the tail is used for this purpose and tied around the Spart.

There are other forms of so-called 'secure Bowlines' that are 'more secure' in my humble opinion.

My view on this may be skewed - as I am commenting from the viewpoint of a rock climber who intends to live a long healthy life.

Mark

Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: Festy on June 21, 2014, 05:41:23 PM


There are other forms of so-called 'secure Bowlines' that are 'more secure' in my humble opinion.


Mark

Mark, your opinion is most assuredly much valued.

Perhaps, if time permits, you might name the bowline forms that you consider 'more secure', and how they would compare to the 'security' of the Double Dragon.

F
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: Festy on June 21, 2014, 08:03:01 PM
Some features the Double Dragon has that other loops lack? (possibly)

1. The DD can be easily verified visually as being tied correctly.

2. Each aspect of dressing the DD by pulling the legs (both loop legs, the bitter end and the SPart), can be carried out in any order.

3. It is easy to see when dressing the knot where each leg needs to be pulled.

4. Resistance to side loading (as far as I can ascertain with just muscle power).

5. Pulling hard on any combination of legs will not capsize or upset the knot (as far as I can ascertain with just muscle power).

I stand to be corrected on any or all of the above, of course.

F

Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: roo on June 21, 2014, 11:57:50 PM
1. The DD can be easily verified visually as being tied correctly.
There are some mistakes that can be made in tying that yields very convincing impostor knots.  Whether they have any especially problematic weaknesses is a topic of investigation.

Quote
4. Resistance to side loading (as far as I can ascertain with just muscle power).
I'm not too sure what you mean by "side loading".  Can you clarify?

Quote
5. Pulling hard on any combination of legs will not capsize or upset the knot (as far as I can ascertain with just muscle power).
As you note, muscle power isn't all that great, but I was able to fully capsize the Double Dragon Loop in 3/16" diameter nylon rope without much trouble by pulling the legs in opposite directions.  In some 5/16" diameter nylon rope, I was able to partially capsize the knot by pulling the legs in opposite directions such that upon normal loading, the knot was unable to return to it's usual shape.  All this was done with mere hand strength.

Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: agent_smith on June 22, 2014, 10:03:05 AM
Quote
In tests of abseil-ropes-joints, the offset water knot
(aka "EDK"="Euro Death Knot" ) proves more secure
under load than the "more complex" offset figure 8 bend
--with the irony that the latter might have been chosen
presuming just the opposite.
Quoted from Dan Lehman

Not intending to steer the subject matter of this thread off-topic but, I again support these wise words of wisdom.

I theorise that the so-called 'EDK' is none other than the Offset F8 bend.

The offset overhand bend (aka offset water bend) is secure and stable provided it is dressed and cinched tight. I use this method of joining my 2 climbing ropes to the exclusion of all other knots. I further theorise that the EDK has been consistently misreported by people who are either parroting others or, by sketchy eye witness reports from surviving members of the party - they would obviously be suffering from shock, they are in a very vulnerable and emotional state and they are generally not expert in roping skills.

Back on topic... I have never used the Double Dragon in mission critical applications (where a human life is at stake). So I have no empirical evidence base from which to comment. Be that as it may, I can confirm that it is definitely not in widespread use in the climbing, caving and vertical rescue community. But that by itself is not evidence to discredit the DD knot.

I will look into this in detail and get back to this site and comment soon...

Mark Gommers

Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: Festy on June 22, 2014, 10:10:36 AM
1. The DD can be easily verified visually as being tied correctly.
There are some mistakes that can be made in tying that yields very convincing impostor knots.  Whether they have any especially problematic weaknesses is a topic of investigation.

Quote
4. Resistance to side loading (as far as I can ascertain with just muscle power).
I'm not too sure what you mean by "side loading".  Can you clarify?

Quote
5. Pulling hard on any combination of legs will not capsize or upset the knot (as far as I can ascertain with just muscle power).
As you note, muscle power isn't all that great, but I was able to fully capsize the Double Dragon Loop in 3/16" diameter nylon rope without much trouble by pulling the legs in opposite directions.  In some 5/16" diameter nylon rope, I was able to partially capsize the knot by pulling the legs in opposite directions such that upon normal loading, the knot was unable to return to it's usual shape.  All this was done with mere hand strength.

Thanks for that, Roo...............that throws it into the 'well maybe not then' category  :D


In paracord I wasn't able to capsize it like you did, but I'm no Mr Universe  ;D (by sideloading I meant pulling apart the loop legs when the knot is dressed)

F
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: Festy on June 22, 2014, 10:12:16 AM
I have never used the Double Dragon in mission critical applications (where a human life is at stake). So I have no empirical evidence base from which to comment. Be that as it may, I can confirm that it is definitely not in widespread use in the climbing, caving and vertical rescue community. But that by itself is not evidence to discredit the DD knot.

I will look into this in detail and get back to this site and comment soon...

Mark Gommers

Thanks, I look forward to that

F
Title: Re: Double Dragon Loop trumps the Bowline Family?
Post by: agent_smith on June 22, 2014, 01:02:23 PM
I have conducted some very quick and dirty (and unscientific) tests on the Double Dragon.

Cyclic loading (which some call 'slack shaking' on this site) will compromise the core (nub) of this structure relatively quickly - unless - it is drawn up and vigorously cinched tight.

In direct comparison, the [Yosemite] Bowline did not require such strict attention to cinch down and compress the core (nub) - it was more resistant to cyclic loading.

This 'testing' was carried out with 8.0mm diameter Sterling USA cord (human rated 17.5kN high strength - my favourite brand of cordage).

Obviously, a lot more testing needs to be done!

Mark