Author Topic: Simple lock for the bowline  (Read 99395 times)

SS369

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Re: Simple lock for the bowline
« Reply #120 on: March 03, 2012, 01:56:07 PM »
My own personal feelings about testing in the extreme are not fear centered at all. I regularly use rope in challenging myself and gravity. But, I can relate to anyone who does not want to take the limited amount of large diameter rope that they own, devise a method of destruction and then do it with the intent of never using it again. Then it is the method(s) for destructive testing. Not everyone has or will go out and purchase a device for this purpose alone. Or will feel it is a great policy to use their vehicle, etc.
So I can understand why it doesn't get done by the many.

Then there are those who wait and let someone else do it, just because.

Let's not hijack this thread to this topic.  ;-)

X1

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Re: Simple lock for the bowline
« Reply #121 on: February 25, 2013, 04:30:38 PM »
The thread "simple lock for the bowline" has held my interest since casting my eyes on it.
There are few ways to achieve the "lock", some easy, some not.

  There were many ideas and pictures in this thread that are quite interesting, and deserve a second life.
  Trying to "lock" the bowline, there is always the temptation to deviate a little bit, and tie a "similar" loop, where an element of the bowline is replaced by something slightly different.
  See the attached pictures for such a bowline-like loop, wih an "8" shaped collar. It is may be considered as "similar" to the bowline presented at Reply#19
http://igkt.net/sm/index.php?topic=19.msg2053n8#msg20538
and the loop presented at Reply#98
http://igkt.net/sm/index.php?topic=19.msg21088#msg21088

« Last Edit: February 25, 2013, 04:36:49 PM by X1 »

SS369

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Re: Simple lock for the bowline
« Reply #122 on: February 26, 2013, 01:41:14 AM »
Nice!
I like that the tail gets squeezed in two places pretty securely.
Now to load it and see how difficult it is to untie, but this will have to wait until the sunshine visits.

SS

Dan_Lehman

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Re: Simple lock for the bowline
« Reply #123 on: February 26, 2013, 10:09:04 PM »
  There were many ideas and pictures in this thread that are quite interesting, and deserve a second life.
  Trying to "lock" the bowline, there is always the temptation to deviate a little bit,
and tie a "similar" loop, where an element of the bowline is replaced by something slightly different.
  See the attached pictures for such a bowline-like loop, wih an "8" shaped collar.
...

Nearly bingo!
Here's a better finish, IMO, with reference to your upper image:
begin collar as you do, white crossing under itself,
but take it under orange eye leg, around and over
itself going back through turNip,
and the out as you do --which makes exactly a fig.8,
and better binds the turNip which itself secures parts.

And this general (unloaded) form may be put as *knots*
with various loadings : as *bowlines* in both directions,
and as a fig.8-based eye knot maybe also in both ways!
(I think that it was in one of the latter that I first recorded
it, and maybe the other-way bowline (much of the wrapping
around eye legs) came first or thereafter; later was the opposite
orientation qua bowline.  (I have photos ... .)

It has just the 2 diameters through the turNip, but seems
to look pretty good, anyway.


--dl*
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X1

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Re: Simple lock for the bowline
« Reply #124 on: February 27, 2013, 02:07:14 AM »
   Thank you, Dan Lehman,
   ...and congratulations for the re-discovery of photography ! It was about time...( 1826 -2013 = 200-13 years )
   
   Nearly Bingo !  :)
   First things first. As you say, the loop in the picture is not a bowline - so let me call it (a particular) "fig.8 loop", for the time being.
   Let me start from the great advantage : At this fig.8 loop, the eye-leg-of-the-bight, by following the path it follows at the point it enters and penetrates the nipping loop, and by the help of the eye-leg-of-the-standing-part, it squeezes the tail on the rim of the nipping loop - a line of defence against slippage which does not exists at all in the case of the "8" loop.
   However... the price we have to pay in driving the working end through this path, is too high.
   0. At the "8" loop, the tail is not squeezed underneath the eye-leg-of-the-bight at the same point it is squeezed at the "fig.8 loop", but it is squeezed on the rim of the nipping loop nevertheless - and by two overlapping segments, not only one. See this point, inside the blue circle, at the second picture.
   1. At the "fig.8 loop", the continuation of the eye-leg-of-the-bight DOES NOT squeeze the continuation of the tail on the eye-leg-of-the-bight - because this continuation of the tail falls into the "canyon" formed there ( between the straight segment of standing part and the rim of the nipping loop), and it is free to slip. So, this is one less line of defence against slippage - and we can not abandon even a single one of our few lines of defence, can we ?  :). See this "canyon", through which the continuation of the tail is free to move, inside the two concentric green circles, at the third picture.
   2. Last but not least : I do not know if I will be able to describe this most serious disadvantage of this "fig.8 loop", in relation to the "8" loop ( and which forced me to present the later but not the former), but I will try :
   The inclination of the plane of the nipping loop in relation to the axis of the loading, which protects it from becoming an open helix, is smaller in the "fig.8 loop" than in the "8" loop. This is due to the different path that the second leg of the collar follows : when it goes around / passes behind the eye-leg-of-the-standing-part, it is not as effective as a tendon (blue double arrow, at the fourth picture), that can drag the straight segment of the standing part towards the nipping loop, than when it goes over / passes in front of it - or, what is the same thing, it can not drag the nipping loop towards the straight segment of the standing part effectively enough, so the nipping loop settles in a smaller, less safe angle (red lines, at the fourth picture) in relation to the axis of the loading. In other words, in the "8" loop, the second leg of the collar follows a path close to the path it would have followed in the case of a standard bowline - and the great advantage of the standard bowline is, as we all know, that the collar pulls the nipping loop toward it, and prevents it from degenerating into an open helix. In the "fig. 8 loop", the plane of the nipping loop remains almost parallel to the axis of the loading - not good !
   I should add just another thing, which can be said for all those attempts to invent a better mousetrap : In the king of knots, the common standard bowline, there is an equilibrium, a balance of structure and form, between the nipping structure on the standing part, ante the eye, and the collar structure on the tail, post the eye. Nothing plus than minimum, nothing is less or more than the other. I am afraid that the various "secure bowlines" are missing this point. We see either over-grown collar structures, or over-grown nipping structures, but we lose this miraculous and beautiful balance of the two structures/forms, that exists in THE bowline...
« Last Edit: February 27, 2013, 11:37:19 AM by X1 »

agent_smith

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Re: Simple lock for the bowline
« Reply #125 on: February 27, 2013, 03:23:51 PM »
This is really interesting. You have my attention.

Will explore these simple locks...

To provide a practical use, these Bowline 'locks' must be secure and stable in a variety of loading profiles - eg so it is suitable as a tie-in knot for climbers.

In particular, the finished Bowline must be resistant to cyclic loading events (ie tension on>>tension off>>tension on>>tension off again...). Cyclic loading is the trigger mechanism for unsecured Bowlines working themselves loose (with potential catastrophic consequences for climbers).

The 'locks' would need to be tested in stiffer ropes as well as softer (ie good hand) ropes. Dynamic climbing ropes vary considerably from brand to brand...

I should disclose that I use my EBSB Bowline variant regularly - and have done so since 2009. I have had no issues with security and stability with the EBSB variant. But, I take X1's point about the increased size of the nub.
Note: I have come to realize that knot strength is an (almost) irrelevant concept - testing for pure breaking load strength to me is (almost) a pointless exercise.

Mark

X1

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Re: Simple lock for the bowline
« Reply #126 on: February 27, 2013, 06:43:31 PM »
   Thank you Mark,
   The original intention of this thread was something a lot more modest than the transformation of the common bowline into a climbing knot. Most of the bowlines presented here are more secure knots than the common bowline, but they are not meant to replace the retraced fig.8 knot used by the climbers.
   I have no experience or knowledge of climbing whatsoever ( I use to declare that the highest peak I have conquered in my life, was the top of a step ladder...), so I can not comment on the complex issue of the safety of any "secure bowline". My gut feeling tells me that, in order for such a bowline to be able to compete with the retraced fig.8 loop, it has to have a double nipping loop and a double collar. The "mirrored bowline", for example, would be a knot than even I could trust my life on !  :) 
   I believe I have tied a great number of all the possible and not too complex bowline-like PET loops, so I have a rough idea of the landscape. However, there are always pleasant surprises, when a competent knot tyer leads us to unchartered territories. Alan Lee, for example, has recently tied many very interesting and good looking bowlines ( see the first attached picture for such a knot, just one of the many he has presented in this Forum ).
   The only bowline that I have tied and can possibly be considered as a "secure bowline", is the Tweedledee bowline, which is nothing but the Tweedledee bend (M.A24) presented by Roger E. Milles in his beautiful book "Symmetric bends", turned into a bowline-like PET loop ( see the second and the third attached pictures ). However, I have not tested it under any of the conditions you describe !  :)
« Last Edit: February 27, 2013, 06:55:11 PM by X1 »

Dan_Lehman

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Re: Simple lock for the bowline
« Reply #127 on: February 27, 2013, 07:59:43 PM »
   First things first. As you say, the loop in the picture is not a bowline
--so let me call it (a particular) "fig.8 loop", for the time being.

Where did I say this?  What I show (which in a *quarter* is much
like what you showed) is a structure that if loaded on the purple
ends "1,2" (i.e., either one qua SPart) is IMO a "bowline"; if on
either of the other ends, a fig.8-based eye knot.

Quote
I should add just another thing, which can be said for all those attempts to invent a better mousetrap :
In the king of knots, the common standard bowline, there is an equilibrium, a balance of structure and form,
between the nipping structure on the standing part, ante the eye, and the collar structure on the tail, post the eye.
Nothing plus than minimum, nothing is less or more than the other.
I am afraid that the various "secure bowlines" are missing this point. We see either over-grown collar structures,
or over-grown nipping structures, but we lose this miraculous and beautiful balance of the two structures/forms,
that exists in THE bowline...

Where "the bowline" fails in performance, something better
must be sought, and we do have failures in security both of
the coming-loose & the slipping-under-load sort (the latter
in some high-strength, slippery line).  (Many of the tail-end-heavy
imbalances are likely to fail in slippage.)

After wrestling with the very stiff old low-elongation rope
(BW II), I'm not confident of having just one solution but
want options; this particularly tough case might be one
best dealt with by some multiplicity of knotting, rather
heavy-handedly.  It really is hard to bend the line around
3 diameters snugly!)


--dl*
====
« Last Edit: March 04, 2013, 06:37:22 PM by Dan_Lehman »

X1

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Re: Simple lock for the bowline
« Reply #128 on: February 27, 2013, 09:44:52 PM »
   First things first. As you say, the loop in the picture is not a bowline

  Where did I say this?  What I show ... is a structure that if loaded on the purple ends "1,2" (i.e., either one qua SPart) is IMO a "bowline";

  No, it is not. It does not have a collar like the collar "the" bowline has ( a "proper" collar) - where the second leg of the collar enters into the nipping loop from the same side the first leg of the collar exits through - so, in either case ( "1" as the Standing end, or "2" as the Standing end ) it is not a bowline. It is one "the-other-way bowline:) :), just as you said - in the sense that the second leg of the collar enters into the nipping loop the other way than it should !

the other-way bowline ...the opposite orientation qua bowline

  Bingo !  :)

See three similar loops, where the simple collar structure of the common bowline has been replaced by a not-so-simple strangle-like one ( Replies #98 and #99 ):
http://igkt.net/sm/index.php?topic=19.msg21088#msg21088
http://igkt.net/sm/index.php?topic=19.msg21089#msg21089
« Last Edit: February 27, 2013, 09:45:28 PM by X1 »

Dan_Lehman

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Re: Simple lock for the bowline
« Reply #129 on: February 28, 2013, 06:07:16 PM »
   First things first. As you say, the loop in the picture is not a bowline

  Where did I say this?  What I show ... is a structure that if loaded on the purple ends "1,2" (i.e., either one qua SPart) is IMO a "bowline";

No, it is not.  It does not have a collar like the collar "the" bowline has ( a "proper" collar)
- where the second leg of the collar enters into the nipping loop from the same side the
first leg of the collar exits through - so, in either case ( "1" [SPart], or "2" [SPart] ) it is not a bowline.
It is one "the-other-way bowline:) :), just as you said - in the sense that the second leg
of the collar enters into the nipping loop the other way than it should !

No to your "no" : as I wrote, "IMO", and as you have acknowledged
elsewhere, some definitions of "bowline" require only the central
nipping loop (aka "turNip") --and that is my position, "proper collar"
be darned!

And my "other way" referred to which side of my intentionally
ambiguous image (with identified *ends* awaiting assigned tasks)
and which part would be the SPart, et cetera.  Given the purple
rope's turNip, taking either of its ends qua SPart yields
a *bowline* "IMO".  (And know that I'm right.)   :P

Moreover, re my "anti-bowline" (which you recognized using "anti"
as for "anti-cyclone" to denote something about direction),
there my determinant is on the returning leg of the eye,
whatever collaring is done (and so in the case at issue above,
one sees a "normal" return & entry of this eye leg).

Quote
  Bingo !  :)

Amen!

Quote
where the simple collar structure of the common bowline
has been replaced by a not-so-simple strangle-like one ( Replies #98 and #99 )

The strangle knot embedded here doesn't work so well,
unable to draw up to its rumored tightness.  Actually, used
qua "tie-off" knot, I find the strangle to be less secure than
I once thought --and have heard some rockclimbers testify that
it came untied on them--, and note that it doesn't make a full
wrap, really, its extension over the (single) overhand form
being not fully a 360degrees wrap in binding effect.  So, for the
task of tail tie-off, I've mused about either a double strangle
or some wrap-wrap-&-tuck knot (stevedore, e.g.).


--dl*
====

ps : re photography, 18xx-2012..., it was a recent news item that
more photos have been uploaded(?) --not certain what was the measure--
in the past year or two than were taken (by some measure)
in all prior history !!!  It was pretty amazing datum,
in that of the "prior history" were many years into the digital era,
but prior the ubiquitous smart-phone-camera ubiquity, I guess !!
« Last Edit: March 04, 2013, 06:33:22 PM by Dan_Lehman »

X1

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Re: Simple lock for the bowline
« Reply #130 on: February 28, 2013, 09:53:00 PM »
No to your "no" : as I wrote, "IMO", and as you have acknowledged elsewhere, some definitions of "bowline" require only the central nipping loop (aka "turNip") --and that is my position

  No. to your "no" to my "no"  :) : as I wrote, and as you know, some definitions of "bowline" require both the nipping loop ( like the one that exists in "the" bowline ), AND the collar ( like the one that exists in "the" bowline ), and that is my position. I do not understand why "your opinion" should become everybody else s opinion - it is your OPINION, not your PROOF. I believe that one of the few persons that has expressed arguments in favour of your opinion, is me (1) - but I am still not convinced 100%, and I can not ignore the fact that most knot tyers are not convinced either. So, when the legs of the collar structure of a eye knot / loop do not exit from and enter into the nipping loop from the same side, I always prefer to refer to it as a "bowline-like" eye knot / loop. I should also remind you that you did not write " this is a "bowline', IMO "- you wrote :

 
Here's a better finish, IMO, with reference to your upper image:

  I know very well that it is hard to repeat something a million times, and do not succeed in convincing even a single one member, about something that sounds reasonable to you... it happens to me all the time !  :) Why do you believe you should have a better luck ? Most knot tyers are very attached to the traditional name and the image of the common bowline, and they are not prepared to accept what seems to them as a radical change, even if there are reasonable arguments in favour of it.  I have not convinced anybody that the nipping loop is something different from a half hitch, which is something that is much more evident to me - but not to anybody else !  :)
 
And my "other way" referred to ...

That was clear - as it should have been clear that I utilized, on purpose, your phrase in another sense, to highlight my point.

Moreover, re my "anti-bowline" ... there my determinant is on the returning leg of the eye, whatever collaring is done (and so in the case at issue above,
one sees a "normal" return & entry of this eye leg).

   (This "returning" leg of the collar, I call the "second leg of the collar". )
   I beg your pardon, but I do not understand what exactly you do mean here : do you call as "normal" the "orientation" of the returning/second leg, as it moves towards the nipping loop ? That makes sense - but the "entry" of this second leg on the nipping loop is through the opposite side from its "exit" : So, if the "entry" and the "exit" of the first leg were "normal", the entry and the "exit" of the second leg ( into/from the opposite side of the nipping loop ) can not be so ! Follow the working end as it "moves" from the standing end to the tail. Watch the side it enters and exits into/from the nipping loop each time. Then, see what I mean : this is not the way the working end of "the" bowline is "moving".

The strangle knot embedded here doesn't work so well, unable to draw up to its rumored tightness. 
Actually, used qua "tie-off" knot, I find the strangle to be less secure than I once thought

   I has presented THREE strangle-like colar structures, not one. They are entangled with the nipping structure of those three loops in three very different to each other ways - so, even if what you say is true for the one or two, it is very unprobable that it is also true for all the three !  :)
   However, I do not deny that this might be the case, indeed - my main objection to your comment about the Strangle is that, in this case, we do not have a common Strangle tie-off knot, we have a Strangle-like knot, used as a collar structure : that is, interwined with the nipping structure in a very complicated way - so it is hardly a Strangle knot at all !
   I suggest you forget about the Strangle as a tie-off knot, and tie those three bowlines and bowline-like knots as they are. I am sure you will find that at least one of them is utilizing this shape "8" collar structure in an interesting and secure way.
   Having said that, I also do not deny that this Strangle-like collar structure seems "over-grown:, in relation to the common nipping loop - I would prefer a bowline-like loop where such a complex collar structure would be accompanied by a equivalently complex nipping structure. In general, I prefer a double collar attached on a double nipping loop - in this case, I sense some equilibrium, also present in "the" bowline, but absent in most of the other better mousetraps ( most of the "secure bowlines", as the Janus bowlines, for example ).

it was a recent news item that more photos have been uploaded?

   No, I have already notiiced that, but I feel I have to repeat the mention, so the attitude would have more chances to be embedded - in the conscious or subconscious side of this nipping loop.
   In the present case, the pictures accompanied the clear description offered in the text, in a balanced way - that was the best thing of it. A clear description, in a clear language (not in any sociolect or argot...) of an interesting knot, AND two pictures of it - we do not demand the gold of the Persian Empire...

1. http://igkt.net/sm/index.php?topic=3233.msg23683#msg23683
« Last Edit: February 28, 2013, 09:56:43 PM by X1 »

Dan_Lehman

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Re: Simple lock for the bowline
« Reply #131 on: March 04, 2013, 06:45:47 PM »
Moreover, re my "anti-bowline" ... there my determinant is on the returning leg of the eye,
whatever collaring is done (and so in the case at issue above,
one sees a "normal" return & entry of this eye leg).

   (This "returning" leg of the collar, I call the "second leg of the collar". )

Perhaps if your desire to be combative got out of your eyes
you could read what you're quoting and spare the reply to
something else which wasn't uttered?  "leg of the EYE" :
do not read "leg of the collar" for this.

 ::)

X1

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Re: Simple lock for the bowline
« Reply #132 on: March 04, 2013, 07:39:18 PM »
  To watch this loop you have presented, and be forced to see it as a bowline ( because the "leg of the eye" is "normal" - whiile, obviously, everything else is not...), THAT got my eyes out !  :)

X1

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Re: Simple lock for the bowline
« Reply #133 on: March 04, 2013, 11:11:22 PM »
   To close this long diversion away from the main theme of this thread, I would like to mention yet another secure bowline-like loop, in the spirit of the "belance" I seek between the nipping structure and the collar structure in the nub of the PET loop knots  / eyeknots (1). Although in this loop the orientation of the two Constrictor links is not the optimum ( alongside to the "vertical" axis of the loading, as in the Tweedledee bowline-like loop ), this knot is compact, it is able to withstand ring-loadimg, and it is worth of further examination, I believe.

1. http://igkt.net/sm/index.php?topic=19.msg26690#msg26690
« Last Edit: March 04, 2013, 11:13:57 PM by X1 »

X1

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Re: Simple lock for the bowline
« Reply #134 on: April 14, 2013, 08:24:46 PM »
   When I had tied the eyeknots shown at Replies #38 and #46 (1)(2), I had chosen a tight double "collar structure" that was resembling a Constrictor knot, in an effort to keep the two adjacent and parallel segments ( the continuation of the returning eye leg and the tail ) "under" the "riding turn" / "bridge" ( the segment which connects the two nipping loops ). Now I have tried those eyeknots again, and I see that the variations where the "bridge" goes "over", and those two parallel segments go "under", are also very secure and tight knots. We can also try the "simpler" Clove-hitch resembling similar double "collar structures", where those segments are not crossed - if we anticipate that the standing end will always remain under tension, the constricting action of the nipping loop would be the main factor that would keep the tail locked inside the knot s nub, so we have to examine in which variations the rim of this loop contact the tail and blocks its slippage more efficiently. In mid-line bends, where we presume that the main line would always be under tension, dfred had chosen the ("simpler" than the Constrictor) Clove-hitch resembling double collar structure (3).

 
Many variations are possible here, including a constrictor instead of a clove hitch.  I didn't identify anything simpler and less bulky than a clove hitch though.  I experimented going either right or left first after the first pass through the loop, but wasn't able to discern much difference, at least when using a clove hitch.
   

1. http://igkt.net/sm/index.php?topic=19.msg20905#msg20905
2. http://igkt.net/sm/index.php?topic=19.msg20922#msg20922
3. http://igkt.net/sm/index.php?topic=3020.msg17965#msg17965
« Last Edit: April 14, 2013, 08:31:44 PM by X1 »