Author Topic: A More Symmetrical Double Dragon  (Read 291 times)

blgentry

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A More Symmetrical Double Dragon
« on: April 01, 2021, 01:43:42 PM »
I've been playing with the Double Dragon a lot lately because it's easy for me to remember and relatively quick to tie, whether it be in the bight or around an object.  I think it's a nice looking knot, except the slight asymmetry on the back side.  I got to playing around and changed it just a little to make it more symmetrical.  I made a video showing the knot and how it is tied:


I think it's an even more pleasing knot now.  Though I don't know if my modification has really made any positive or negative difference in the performance of the knot.

This may not be anything new, but I haven't been able to find this knot discussed in the searching I have done. 

Thanks for looking,
Brian.

tsik_lestat

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Re: A More Symmetrical Double Dragon
« Reply #1 on: April 01, 2021, 04:52:51 PM »
Hello blgentry, i understand that you are a double dragon aficionado!!

Indeed, it has been tied before, known as double tugboat B, or double flying bowline or symmetrical double dragon if you like!

Check out this link .....   https://igkt.net/sm/index.php?topic=5628.0

The single version (one wrap through the crossing knot/flying bowline), may also be considered as the midline version of a cowboy bowline, if you leave a bigger tail.

Thanks for your nice TIB and` in the end ` tying demonstration of both good knots anyhow!
« Last Edit: April 01, 2021, 04:55:08 PM by tsik_lestat »
Going knots

blgentry

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Re: A More Symmetrical Double Dragon
« Reply #2 on: April 01, 2021, 07:01:45 PM »
Thanks for taking the time to reply.  So it's a "double tugboat version B".  Hmm.  Doesn't seem to be widely documented.  Probably because it's no more useful than the original double dragon.  I like it better, but just because it looks nicer.

Thanks again.

Brian.

Dan_Lehman

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Re: A More Symmetrical Double Dragon
« Reply #3 on: April 01, 2021, 11:45:56 PM »
You should try loading them and then examining
the knots to see which looks better as best you
might assess strength (or lesser-hurt-to-rope),
and also ease of untying.
(Body weight on that cord you use should be
 a fair bit of loading.)

Thanks,
--dl*
====

ps : Nice growling sounds you got on SPart direction!   ;D

blgentry

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Re: A More Symmetrical Double Dragon
« Reply #4 on: April 02, 2021, 02:21:05 PM »
I have previously tested the Double Dragon and this variation of it by tying around a post and then pulling my body weight against it, even "bouncing" my weight to try to really stress it.  Both the DD and the symmetrical DD become very tight.  The collar becomes rock hard and difficult to move.  It will move, but it takes more effort than I would like.  I can untie it with my fingers and nails and a half minute of effort.

By contrast the Yosemite Bowline, when stressed the same way, unties with ease.  Almost as if it had not been loaded at all.  I hate the regular bowline (sorry knot people), but I like the Yosemite a little.

For a while I was a big fan of the Zeppelin loop.  But I've found that if I don't tie it for a few months, I just can't remember how.  It's a very weird structure in it's loop form that I can't seem to internalize.  Also, I've recently read here that the loop form of the Zeppelin really does not take advantage of the design features of the Zeppelin Bend since the loading is different.  It's also not aligned with the center of the loop which seems less optimal than it could be.

So now I'm left with the DD, or the symmetrical DD, both of which are easy to remember and easy to tie, but get a little bit jammed when you load them hard.  Or the dreaded bowline variants.  I suppose I could tie figure 8s or figure 8 follow throughs but I think those knots jam a bit too.  I have not tested them myself.

Brian.

blgentry

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Re: A More Symmetrical Double Dragon
« Reply #5 on: April 03, 2021, 10:00:24 PM »
I just did a loading test with my ultra cheap cord shown in the video.  It has some kind of soft core and presumably nylon as the sheathing material.

I tried a few loops around a post and loaded them by wrapping the cord around my back/bottom and put my weight into them several times.  The results were kind of as expected.  From hardest to untie to easiest:

4.  Symmetrical Double Dragon:  Locked up pretty tight.  I read something here in another thread that helped though:  Ring loading the loop by jerking on the ring side to side loosened the collar up a lot and made it easier.
3. Zeppelin Loop:  Not very hard to untie, but not exactly "loose" either.  Took just a bit of extra effort.
2.  Yosemite Bowline:  This is almost a tie with the Zeppelin, but just a smidge easier to untie.  I could easily have reversed these two entries.
1.  Anchor Hitch with two half hitches to secure:  This one isn't a loop at all.  It was pretty trivial to untie.  Just kinda poking at it a bit and pulling and it came right open.  This reinforces my belief that hitches are best for "tie this thing to a post" duties.  The hitch stayed exactly where I put it, all nice and snug up to the post.  Every loop here tried to fall until I positioned it where I wanted and applied tension.  Then when tension was removed, they fell again.  The hitch stayed in place, was the easiest to untie, and seemingly is just as strong.  The only down side I can see is if you are tying something that will be cyclicly loaded over and over again.  That might untie the hitch eventually.  It certainly could untie the last half hitch.  In those situations a loop would be better.  Or a hitch with a strangle knot to finish it.  But that kinda defeats the purpose of your "easy to untie hitch".

Brian.

Dan_Lehman

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Re: A More Symmetrical Double Dragon
« Reply #6 on: April 05, 2021, 07:47:19 PM »
I have previously tested the Double Dragon and this variation of it by tying around a post and then pulling my body weight against it, even "bouncing" my weight to try to really stress it.
Yeah, sometimes the shock-loading even merely manually
puts a good deal of force into the knot.  But maybe a more
sure method is to load w/simple 2:1 pulley arrangement
(e.g., with carabiner or some metal ring), and a little bounce
to boost force back towards actual 2:1 over the friction-reduced
total coming w/o (e.g., I've balanced 45# vs 62.5# with slippery
cable-pulling tape over a 'biner!).

> Both the DD and the symmetrical DD become very tight.
> The collar becomes rock hard and difficult to move.

What "collar" ?  IMO, the most collar-like part is the
SPart's turn around (collaring, thus) the eye legs;
and, yes, that will become tight, but as it's a surrounding
of 2 legs that are also loaded, there can be some bit of
play with shifting their positions, maybe?


Quote
I hate the regular bowline (sorry knot people), but I like the Yosemite a little.
You should LIKE it, but for use at appropriate conditions.
As for the YoBowl, try it with a "wide swing" --i.e.,
it turns LESS tightly around the single returning eye leg
and so crosses over/upon the SPart to tuck into the
other side of that,
AND THEN
put in what is called sometimes "Lee's Lock" : tuck
the tail back out through the central nipping loop,
a more sure securing and one that bears upon
the SPart (given this "wide swing")!

Quote
Also, I've recently read here that the loop form of the Zeppelin
really does not take advantage of the design features of the Zeppelin Bend (aka "Thrun's Joint")
since the loading is different.  It's also not aligned with the center of the loop
which seems less optimal than it could be.
Eh, so what.  The knot can be tied and be pretty secure
and easy to untie, nevermind the armchair'd lament of
being imperfectly zep'd!  (There are ways to get more
*balance* & zep-ness but it's a dubious gain, IMO.
Ashley's #1452 & a not-fully-traced #1425 make
nice eye knots, too.

Quote
So now I'm left with the DD, or the symmetrical DD, ...
Or the dreaded bowline variants.  I suppose I could tie figure 8s or figure 8
follow throughs but I think those knots jam a bit too.
There are many BWL variations that should not give dread,
and the Lehman8 is a variation on the Fig.8 EK which is
fairly simple knot, slack-secure and pretty easily loosened.
cf. www.zetatalk3.com/docs/Knots/Knot_Knowledge_Photo_Illustrations_2004.pdf
AT PDF PG. #211 (!).  (And, while in this neighborhood,
do consider the Locktight eye knots of pp.212ff!)
Then beyond these is a single BWL in the bight, which
is a more surely tied variation on the YoBowl.  Then I show
a "strong (read 'exterior-loaded') form Fig.8" EK, to which
one fellow's testing found it less strong (than loading its
tail --which yields the "interior-loaded" version) and to
his point, much less easily loosened.)


Cheers,
--dl*
====

blgentry

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Re: A More Symmetrical Double Dragon
« Reply #7 on: April 06, 2021, 08:31:47 PM »
I don't mean to be difficult, but most of these knots are very hard to follow and recreate.  Lee's locked BWL is odd because he ties it in some sort of reflected configuration that I can't easily figure out.  That's actually my problem with the BWL in particular.  You must get the orientation of the initial loop correct or it falls apart.  This shouldn't be hard should it?  But it IS hard because it seems that everyone has their own way of tying that knot.  With the standing end away.  Or with the standing end near.  Tied right side up, or tied upside down.  While I am definitely a knot fan, I have not memorized all 4 (or is it 8?) directions of tying most knots.  For me to visualize it, I need to do it in the same way each time.  In the case of the bowline, that means standing end towards me, then overhand loop with the loop to the left.   Then it's easy.  But if you suddenly make the loop *underhand* to the left it's now "hard" because the knot is upside down from my perspective.

I'm clearly still a beginner, even after having done this a good bit over the past few years.  I can't remember "overhand loop to the left" for the bowline unless I tie it at least a few times per month.  If I go 6 months without tying a BWL, then you can be sure I'll screw it up on my first try.  This is why I  am not a fan of the BWL or any of its variants.  The DD, on the other hand, or the Zeppelin Loop, are both very easy to remember and do not seem to have endless variants or reflections.

I appreciate all of the references and recommendations.  Thank you.

Brian.

KC

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Re: A More Symmetrical Double Dragon
« Reply #8 on: April 07, 2021, 10:49:01 AM »
DBY for me, but as with all of this; works well for me because of rope choice.
If 'listen' to rope in hands as tying, will tell you if too stiff to seat correctly for even DBY form of Bowline, let alone most other; especially that follows same classic lines of older shown knots.


i favor knots of at least 3x180 arcs , like Double Bowline.
Yosemite Tie Off keeps tail/Bitter end tidy, more security and presents a 'cleaner' more open fixed eye w/o tail visually obscuring.  More like trying to positively hit openness of  larger, wider spliced eye or even hook w/o tail wagging in the way, and then too as go to Sheet Bend etc. too, nice to have tail out of the way.
Also like tape on end; not always dual color but should contrast rope and be different than other end; so can ask for the blue end or red etc.  Taped length is guide for should be outside of knot, and if start there and tape starts disappearing would be signature of creep.  Not so necessary in DBY, but tape strategy is just for all knots, just falls to DBY here.  Think made vid in '90s, but strategy has survived test of time with me, in fact more than me!
« Last Edit: April 07, 2021, 10:51:11 AM by KC »
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We now return you to the safety of normal thinking peoples.
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Dan_Lehman

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Re: A More Symmetrical Double Dragon
« Reply #9 on: April 08, 2021, 01:00:13 AM »
That's actually my problem with the BWL in particular.
You must get the orientation of the initial loop correct or it falls apart.
This shouldn't be hard should it?
But it IS hard because it seems that everyone has their own way of tying that knot.
IMO, a BIG problem with the BWL being understood
is that it is almost universally shown from the WRONG
SIDE/face.  (Mark Gommers's BWL document calls the
right side "the detail view"; I wish he'd stick much MORE
of that view and nearly none of the other, but surmise that
he relented to some *popular demand* to see things as
they always have been shown over & over & over ... .)-:

And yet the sheet bend is more often shown from
the correct side (to well see the hitching line's crossing
point, with bight legs' parallel passage easily understood).
*I* recall vaguely recognizing how the sheet bend worked,
how the hitching line crossed over & nipped itself; but I
did NOT transfer this understanding to the BWL, so far
as I can now --decades later-- recall, of my 11-13? years
acquaintance w/some knots of marine use.

If you learn the quick-tie method of taking the ("working")
end out, UNDER --this for climber tie-in orientation--
the SPart, bringing then the end back over-down-&-out,
you cast into the SPart all of this movement, and have
the knot's turn & returning eye leg properlyl oriented.

(Otherwise, FYI, if you just poke the tail through the
formed nipping loop of the SPart and go around and
BACK THROUGH SAME WAY >>AND REPEAT THIS<<,
you get either a dbl.Myrtle or dbl.Bollard loop
both of which will work okay, regardless of how the
repeated through-loop tucking is made --whereas
without the repetition, one can get the inferior
versions of the knots.)

Now, that "Lee's lock" for the YoBowl is a quite
simple tucking the tail back through the SPart's
nipping loop --purely an extension to the YoBowl:
you do IT, AND THEN ... make the tuck back into
the knot, which gets a surer lock.  And, as I recommended,
it's better to "swing wide" and put some contact across
the SPart (and accommodate firmer ropes that don't
play nice w/1-diameter turns!).


--dl*
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agent_smith

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Re: A More Symmetrical Double Dragon
« Reply #10 on: April 08, 2021, 01:54:52 AM »
Hello Blgentry,

I'll try to address some of the issues you have identified...

Quote
But it IS hard because it seems that everyone has their own way of tying that knot.  With the standing end away.  Or with the standing end near.  Tied right side up, or tied upside down.  While I am definitely a knot fan, I have not memorized all 4 (or is it 8?) directions of tying most knots.
All knots have a mirror version - both versions being equally valid.
Have a look at the attached image (below).
What you are describing is the natural human hand dominance. With few exceptions, most people have a dominant hand (right-handed versus left-handed).
When a person first learns to tie a knot, there will also be some influence from the 'teacher' - who also would have a dominant hand.
Pick up any book about knots and you'll generally see only one orientation of a knot illustrated (it is rare for any knot book author to show the mirror orientation - or even to discuss it).

Most right-hand dominant people tend to hold the knot in their left hand - and use their right hand to perform the tying maneuvers.
The manner in which the knot is held also aids in observation (so hand movements don't obscure key steps in the tying sequence).

Seasoned knot tyers will have developed very specific hand movements - which are hardwired into their long-term memory.

Quote
In the case of the bowline, that means standing end towards me, then overhand loop with the loop to the left.   Then it's easy.  But if you suddenly make the loop *underhand* to the left it's now "hard" because the knot is upside down from my perspective.
Again - what you are describing here is your personal visual cues - which help guide your progress in tying the knot.
I would point out that descriptors such as  'underhand' and 'overhand' are actually meaningless!
Consider an astronaut floating in space - is there an up or a down?
A much better way to describe this is using the concept of 'chirality'.
Take note of the way in which you form a loop - it will either be S or Z chirality.
Using this approach to describe the knot geometry - it is valid in any reference frame.

per Dan Lehman:
Quote
IMO, a BIG problem with the BWL being understood
is that it is almost universally shown from the WRONG
SIDE/face.  (Mark Gommers's BWL document calls the
right side "the detail view"; I wish he'd stick much MORE
of that view and nearly none of the other, but surmise that
he relented to some *popular demand* to see things as
they always have been shown over & over & over ... .)-:

Clearly there is a lot going here - and that technical paper on Bowlines does a reasonable job of pointing out the different perspectives of a [a] 'Bowline'.
Put another way, there are few books or technical papers in existence which bother to explore these technical aspects.
Harry Asher was likely first to publish the concept of 'handedness' (chirality) - but he stopped well short of fully investigating all of the the technical detail.

The paper has been updated - Always visit this webpage to view the latest revisions: http://www.paci.com.au/knots.php

No technical paper on knots will ever satisfy everyone's notional view of what is 'right' or 'wrong'.
I feel confident in stating that my Bowlines technical paper is the most detailed and complete work currently in existence.
A huge amount of effort went into producing that paper (and the other papers on my website) - and it is all free to download.
« Last Edit: April 08, 2021, 01:57:35 AM by agent_smith »

KC

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Re: A More Symmetrical Double Dragon
« Reply #11 on: April 08, 2021, 09:46:33 AM »
To me, L-earn the mechanics that are invoking; and form rope as an architecture to that target.
Simply, that has it's own mnemonics, that leave left/right; usual or upside down; way behind as go forward.
.
Chirality is a human reference, can help in communication etc.
But functionally is window dressing that blurs the real topic to me; so i try to squint past it.
.
Being able to flip something upside down in head, left to right etc. , or even play something backwards to verify or reverse engineer;
can be tough mental exercise, but has a great payoff in many things even beyond ropes (if there is such a place ;D !)
.
i do prefer slip knot method of making Bowline, especially with double turns as eye of needle to reeve thru then around SPArt and back thru needle eye.
Slip knot method instead brings the mountain to Mohammed thru the eye of needle and then pulls back to leave line threaded into position.
>>a single turn (1x180 arc)in Standard Bowline etc. to me is a purposeful pass of force @ minimal cost/friction loss, with 1D pull
>>real gripping, 2D stability and greater force reductions in Round Turn (3x180 arcs) always, so favor DB(Y)
.
To me, Sheet Bend has an escape/bight side and a Half Hitch (termination/Hitch type) lock;
that should be equal or stiffer to what is now host escape side, and between 50-100% of escape side diameter;
to impose lock's will most concentrated against would be escapee.
.
Bowline, similar breakdown, only HH is a pass thru type/pulled from both ends like pre-fix to Timber in Killick.
But still lock vs escapee, only here leaving eye.  But at the end of the day, it is whatever 'poem' of telling that works for you.
.
By this logic tho, a Square/Reef as a Bend fails as 2 escapees waiting for chance to runaway/free.
>>the only maybe-baby lock is to the off side, not the primary side.  here the lesser is trying to control the greater
Only locks positively when used against round swell, as a change in force direction applied and nipping self against host 2x
>>here must be in same/matching materials firmness, elasticity, texture and diameter etc.
>>for must get double Nip of equal value, for if has more advantage at 1st nip, then must lose that advantage in 2nd nip.
For a Sheet Bend, we simply cross 1 leg from 'low voltage' off side where is trying to lock against primary force;
>>and bend that leg to the primary force side to now give primary force lock to hold primary force more properly.
.
For me there is continuity, more than separate lessons in this as an overall framework.
1 knot reminds of lessons of another in cross comparison etc.
Rope parts fitted together to mechanical force control objective; more than right or left.
Targeting extruding the locking mechanism, more than left or right.
« Last Edit: April 08, 2021, 10:14:17 AM by KC »
"Nature, to be commanded, must be obeyed" -Sir Francis Bacon
We now return you to the safety of normal thinking peoples.
~ Please excuse the interruption; thanx -the mgmt.~

blgentry

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Re: A More Symmetrical Double Dragon
« Reply #12 on: April 08, 2021, 08:08:44 PM »

A much better way to describe this is using the concept of 'chirality'.
Take note of the way in which you form a loop - it will either be S or Z chirality.
Using this approach to describe the knot geometry - it is valid in any reference frame.

I'll have to read the section in your paper on this.  The initial illustration I looked at seemed backwards to me.  I.E. I would call your S a Z and vise versa.  Again, I need to re-read it.  But the concept makes sense.



Quote
The paper has been updated - Always visit this webpage to view the latest revisions: http://www.paci.com.au/knots.php

No technical paper on knots will ever satisfy everyone's notional view of what is 'right' or 'wrong'.
I feel confident in stating that my Bowlines technical paper is the most detailed and complete work currently in existence.
A huge amount of effort went into producing that paper (and the other papers on my website) - and it is all free to download.

I read some of this, but not even close to all of it.  I just skimmed it a bit.  It really is quite the work.

I came away with an understanding of something that was bugging me:  Bowlines can be tied with the loop in one of two different orientations, which produce two DIFFERENT knots, which are mirrors of each other in some way.  But, each of those orientations can be tied with the tail inside or outside of the main ring (the big loop of the knot that goes around an object).  Which means there are really at least 4 variants of a "basic bowline".

This is what was getting me about tying bowlines.  It's not that I can't do it.  It's that it is so easy to inadvertently tie a mirror, or an "outside tail" version, or BOTH, and not be sure about it.  If you are seasoned at knot tying, this probably becomes a fun aspect of it.  Being able to tie whichever of the 4 basic variants you want at will.  But for someone trying to gain proficiency with knots, it's a hinderance.  It represents (at least) two more variables in tying the knot.  Which, when compounded with tying from different directions (standing end facing or standing end away) now REALLY makes it confusing.

Thus my conclusion that I do not like any of the variants of this knot.  Not because it is a bad knot.  But because it has too many variables.  If I want to get a knot right, I'm tying one that has as few variants as possible.   But talk to me again in a year or two and I might have suddenly become a bowline enthusiast.  <shrug>

Thank you for the discussion.

Brian.

agent_smith

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Re: A More Symmetrical Double Dragon
« Reply #13 on: April 09, 2021, 04:10:31 AM »
Quote
I came away with an understanding of something that was bugging me:  Bowlines can be tied with the loop in one of two different orientations, which produce two DIFFERENT knots, which are mirrors of each other in some way.  But, each of those orientations can be tied with the tail inside or outside of the main ring (the big loop of the knot that goes around an object).  Which means there are really at least 4 variants of a "basic bowline".

Consider that nobody is born from their mother as a gifted knot tyer (with the exception of Alan Lee - he was a born knot tyer).
We all have to learn the skills.
Can you recall the first time you learned to drive a manual (gear shift) car?
You had to take your foot off the accelerator, push the clutch pedal, keep one hand on the steering wheel and the other hand on the gear shifter.
While all this was going on, you had to stay in your lane and remain on your side of the road.
I presume you have a manual car license?
I also presume that these days, you can easily change gears and hold a conversation at the same time?

I'm also still trying to perfect my kayak roll in turbulent white water on a wild river - so I can roll back up even in washing machine conditions!
Its something I still haven't perfected - when you're upside down in a raging torrent - being pushed by hydraulics and bashed against submerged rocks - its not easy to confidently roll back up.
When you're upside down in those conditions, its hard to get your bearings and get set up in the correct position to execute a roll (everything is backwards and confusing).

...

Have you tied a #1047 Figure 8 knot (eye knot)?
There are 4 different ways that you can tie that knot too!

You'll find that most knot tyers form their knots in a certain way - and this is influenced by their 'handedness' (ie left-hander or right-hander).
There are some interesting technical papers on knot forensics - eg just by examining how a criminal tied a particular knot can reveal much about that person.

...

Ashley generally illustrates all of his 'Bowlines' with Z (right-handed) chirality.
#1010 Simple Bowline has the tail inside the eye.
#1034 1/2 has the tail outside of the eye.

...

Out of interest, have a look at several different knot books... take note of the way they illustrate their simple 'Bowlines'.
What do you notice?
You could also do some research on the #1431 Sheet bend.
Take note of how this 'bend' is illustrated by various authors...

EDIT NOTE:
Image added
« Last Edit: April 09, 2021, 09:58:26 AM by agent_smith »