International Guild of Knot Tyers Forum

General => Practical Knots => Topic started by: xarax on September 13, 2011, 01:04:36 PM

Title: How to improve the security of the bowline. Two simple instructions.
Post by: xarax on September 13, 2011, 01:04:36 PM
   The somewhat naive definition of the bowline, as an end-of-line fixed loop based upon two elements, a simple or complex TIB nipping loop on the standing end, (before the tip of the bight), and a simple or complex collar on the working end, (after the tip of bight), has an additional  advantage :  It helps us paint a simple mental picture of this knot, that can be easily improved in a straightforward way : So, if we wish to improve the security of the (common or Eskimo) bowline, we can
1), just add more elements on top of the already existing ones, or we can
2), replace the simple (original) elements by more complex/convoluted (modified) ones.

1.  Tie more than one simple nipping loops, and/or more than one simple/"proper" collars. This is the easier and more obvious way to improve the security of the common and the Eskimo bowlines : you just do the same thing you have already done, at the same or at another part of the knot.
   a). The additional nipping loops can be tied in any of the three tensioned limbs of the bowline: the standing end, the eye leg of the standing part ( before the tip of the bight) and the eye leg of the bight (after the tip of the bight). ( See, for example, the Water bowline, or the Ice bowline (1).)
   b). The additional collars can be tied by a working end that exits the nipping loop, makes a U turn around any of those three limbs, and returns into the same nipping loop. ( See, for example, the Janus (A, B, C) bowlines (7), (2).)

2. Tie more complex types of nipping loops, and/or more complex types of collars.
   a). The more complex/convoluted nipping loops can be TIB (tied in the bight) structures that are tied on a tensioned limb, in an effort to increase the contact area between the nipping loop and the working end/tail that passes through it. ( See, for example the Double bowline, the Double crossed-coils bowline (3), the Girth hitch bowline (7), the Constrictor bowline (4), or the Pretzel bowline (5).)
   b). The more complex/convoluted collars can be a double or triple collar, or a combination of a "proper" bowline collar with a Myrtle collar around a segment of a tensioned limb, or even around a segment of the nipping loop. ( See, for example, the Yosemite bowline (7), the EBSB and EBDB bowlines (7), or the SS369 bowline (6).)

1.   http://igkt.net/sm/index.php?topic=1929.0
2.   http://igkt.net/sm/index.php?topic=1202.msg19317#msg19317
3.   http://igkt.net/sm/index.php?topic=3550.msg20220#msg20220
4.   http://igkt.net/sm/index.php?topic=3150.0
5.   http://igkt.net/sm/index.php?topic=1940.0
6.   http://igkt.net/sm/index.php?topic=19.msg20538#msg20538
7.   http://www.paci.com.au/downloads_public/knots/02_Bowlines.pdf
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: Mobius on April 04, 2015, 06:15:01 AM
(Hmm... a site warning tells me this thread is 'old' and I should consider posting elsewhere. For better, or worse (ie a waste of my time  ;) ), I have posted here).

I am interested in developing a secure bowline that is TIB and is very easy to tie in both a PET (end loop) fashion and is also able to be used (practically) as a secure mid line loop. With particular regard to being TIB, I believe for such a bowline to be considered 'useful' it would need to be as secure (if not more so) than an Alpine Butterfly Loop and as quick and easy to tie in the bight (or at least nearly so). For all practical purposes, I do not see a mountaineer even considering a bowline as a fixed mid line loop unless it is very easy to tie reliably, is able to be ring loaded,  and has been tested as offering security in suitable climbing type ropes.

With the above in mind, perhaps the "Two simple instructions" should be broadened to include; 3) easy and reliable tying methods in both PET and TIB forms, and; 4) able to resist ring loading.

I realize that a bowline that does all these things is a rare beast indeed (not discovered yet as far as I know).

Note that I am discounting any known bowline that is 'supposedly' TIB, but is nearly impossible to tie reliably from a practical perspective. I am making a distinction between a theoretical TIB bowline and a practical TIB bowline. This latter point is relevant I think as I am sure I am not alone in having tried to de-construct a relatively basic bowline that, designed initially as an end of loop knot, just happens to be TIB. In many such bowlines, I have often encountered that it is VERY easy to make one wrong twist/turn when trying to tie them in the bight to only end up with a 'slip knot' style bowline or, worse still, one that just falls apart altogether! If someone is hanging off the side of a mountain, in the cold and rain, the knot chosen better be secure and easy for them to tie. Otherwise, forget it. For this reason, there are probably many so-called TIB bowlines that should be in the 'forget' category from a practical standpoint I believe.

Cheers,

mobius

[changed which for that]
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: Twine on April 04, 2015, 12:42:58 PM
I am interested in developing a secure bowline which is TIB and is very easy to tie in both a PET (end loop) fashion and is also able to be used (practically) as a secure mid line loop. With particular regard to being TIB, I believe for such a bowline to be considered 'useful' it would need to be as secure (if not more so) than an Alpine Butterfly Loop and as quick and easy to tie in the bight (or at least nearly so). For all practical purposes, I do not see a mountaineer even considering a bowline as a fixed mid line loop unless it is very easy to tie reliably, is able to be ring loaded,  and has been tested as offering security in suitable climbing type ropes.

The Double Dragon loop does all that, but I'm not sure if it's really a bowline. Also, I'm not sure how thoroughly it has been tested.

Instructions for how to tie it can be found at http://www.southee.com/Knots/Knots_SingleLoops.htm (http://www.southee.com/Knots/Knots_SingleLoops.htm)

/Twine
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: xarax on April 04, 2015, 12:55:54 PM
   The Double Dragon loop does all that

  Indeed, the Double Dragon loop should also be mentioned and compared to the other TIB PET loops. About my opinion on this knot, see :
   http://igkt.net/sm/index.php?topic=4919.msg32215#msg32215
   The above cited thread contains information about other TIB loops, too.
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: Twine on April 04, 2015, 02:42:20 PM
I'm glad you agree, Xarax. I read the thread you linked to, and it was interesting to read your thoughts about the dressing of the Double Dragon loop. I had not given that much thought before, but after some consideration, I now think that the correct way to dress it is the one where the turn encircling the standing part is the widest, simply because wider turns in a knot contribute less to wear, even in ropes that are strong enough to withstand breaking even if they are tied with knots with sharper turns in them. Luckily, this is the form of dressing that usually forms spontaneously in the Double Dragon loop. I've never seen the other form except when I deliberately deform the knot.
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: roo on April 04, 2015, 04:59:24 PM
I am interested in developing a secure bowline which is TIB and is very easy to tie in both a PET (end loop) fashion and is also able to be used (practically) as a secure mid line loop. With particular regard to being TIB, I believe for such a bowline to be considered 'useful' it would need to be as secure (if not more so) than an Alpine Butterfly Loop and as quick and easy to tie in the bight (or at least nearly so). For all practical purposes, I do not see a mountaineer even considering a bowline as a fixed mid line loop unless it is very easy to tie reliably, is able to be ring loaded,  and has been tested as offering security in suitable climbing type ropes.

The Double Dragon loop does all that, but I'm not sure if it's really a bowline. Also, I'm not sure how thoroughly it has been tested.

Instructions for how to tie it can be found at http://www.southee.com/Knots/Knots_SingleLoops.htm (http://www.southee.com/Knots/Knots_SingleLoops.htm)

/Twine
It's been discussed before.  It is jam prone as a midline loop when the parent line is under tension, or when tied as a bend as Dave Root has depicted on his site. The Double Dragon Midline Loop variant doesn't seem to be jam prone when the loop is loaded and either the standing part is pulled by itself or when the loop is loaded and what is usually the free end is pulled by itself.

In other words, the midline variant is OK when pulled on from one side only, which is very limiting.

I was doing some shake testing of the double dragon loop with some Bluewater II, and found that it popped open and untied much earlier than I'd prefer when compared with other similar size or complexity loops. 

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.

In summary, this is a poster child for why you should not try to limit yourself to one knot.  In trying to cram multiple applications into one knot, you get something that is lacking in nearly all aspects.  Learn the language of knots, not just one or two words.

P.S.  The reason security requirements for midline loops are typically lower than end loops is that you're typically far away from the ends of the rope in a midline application with the added benefit of all the weight of those long ends.

Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: Twine on April 05, 2015, 12:06:01 AM

It's been discussed before.  It is jam prone as a midline loop when the parent line is under tension, or when tied as a bend as Dave Root has depicted on his site. The Double Dragon Midline Loop variant doesn't seem to be jam prone when the loop is loaded and either the standing part is pulled by itself or when the loop is loaded and what is usually the free end is pulled by itself.

In other words, the midline variant is OK when pulled on from one side only, which is very limiting.

I was doing some shake testing of the double dragon loop with some Bluewater II, and found that it popped open and untied much earlier than I'd prefer when compared with other similar size or complexity loops. 

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.

In summary, this is a poster child for why you should not try to limit yourself to one knot.  In trying to cram multiple applications into one knot, you get something that is lacking in nearly all aspects.  Learn the language of knots, not just one or two words.

P.S.  The reason security requirements for midline loops are typically lower than end loops is that you're typically far away from the ends of the rope in a midline application with the added benefit of all the weight of those long ends.

I can't argue with what you say, it's all true. Personally, I think the best is to use the Butterfly Loop for a midline loop and a double-knotted bowline (which I like to start like a double overhand noose and finish by tucking the tail through the collar) as a PET end loop. But those are two knots, so that wouldn't satisfy Mobius' specific request for one and the same knot, (which also must be a TIB bowline) for all purposes. I've never used the Double Dragon as a midline loop, except as idle experiment, so I didn't know it could jam in the circumstances you describe, but on the other hand, Mobius didn't specify non-jamming or ease of untying for his ideal knot.

Do you think Mobius or anyone will ever be able to find a single knot that fulfills all his specifications if we also include non-jamming and ease of untying in the specs? I'm pretty sure no such knot exists right now, because if it did, everyone would be using it.

A question about your shake test: the Bluewater II line, is it very springy and slippery?

/Twine
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: xarax on April 05, 2015, 12:47:46 AM
   I'm pretty sure no such knot exists right now,

  Do not !  :) :)

...because if it did, everyone would be using it.

  And, please, do not use THAT "proof" ! !  :) :)
  Knot tyers do not use the best knots, they use the knots they had learnt when they were still young enough and were able to memorize things, even if they did not understand them  :), or they use only the knots themselves had "invented". In any case, they are notoriously consistent in their greatest knotting principle : they do not tie other people s knots !  :) :) :)   
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: Mobius on April 05, 2015, 03:20:16 AM
.....
I've never used the Double Dragon as a midline loop, except as idle experiment, so I didn't know it could jam in the circumstances you describe, but on the other hand, Mobius didn't specify non-jamming or ease of untying for his ideal knot.

Do you think Mobius or anyone will ever be able to find a single knot that fulfills all his specifications if we also include non-jamming and ease of untying in the specs? I'm pretty sure no such knot exists right now, because if it did, everyone would be using it.
.....
/Twine

The first post was about security, so I stuck to that theme. However, I certainly would like to come up with a knot that is non-jamming, easy to untie, as well as everything else I described. I could also add to all the above that the tail should be able to be loaded securely along with, or instead of, the standing part. Tying a TIB loop that cannot be loaded on both ends, as well as the loop (perhaps individually), could be a big security issue, so end loading flexibility is a requirement.  I don't want much from a knot, do I :)

As a class of knots I was under impression that bowlines are typically non-jamming and easy to untie.The collar structure of many bowlines certainly helps in the latter untying aspect while the nature of the nipping turns (in particular) probably goes along way towards the knot jamming, or not. Along with potential strength and security, the supposed ease of untying and non-jamming is why people are so interested in bowlines, is it not?

The Double Dragon is certainly a nice knot, I like many aspects of it. Thank you for sharing.
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: Mobius on April 05, 2015, 06:51:50 AM
... bowlines are typically non-jamming and easy to untie. The collar structure of many bowlines certainly helps in the latter untying aspect, while the nature of the nipping turns (in particular) probably goes along way towards the knot jamming, or not.

  It is the other way around !  :) The nipping turns make the bowlines easy to untie, and the collar structures ( well, some collar structures, combined with additional nipping turns ...) probably goes towards the knots jamming.
  ( See : http://igkt.net/sm/index.php?topic=4851.0 )

  P.S. There are some exceptions to this : The Clove- or the Constrictor-based double bowlines ( where the nipping structure is a Clove hitch or a Constrictor binding knot ), may jam, indeed - or, at least, become very difficult to untie.

Another new thing to consider :)

The top collar is where I typically start loosening a bowline to untie and the knot tends to come undone easily after that. At least that is true for the bowlines I have been playing with. Maybe I just have not been able to load them sufficiently for them to jam ;) The clove Hitch based nipping structure was the one I was thinking of probably being a problem, though a Constrictor base would likely be a problem too.

All very interesting to consider and perhaps a big balancing act is required between enough nip turns and collars to make a knot secure in all it's loading facets vs too many nip turns and collars (or ill conceived ones) that might cause the knot to jam.
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: Dan_Lehman on April 05, 2015, 09:11:24 PM
[S-] I am interested in developing a secure bowline [that] is TIB
[P-] and is very easy to tie in both a PET (end loop) fashion and
[M-] is also able to be used (practically) as a secure mid line loop.
Here we should question the goal of putting all of these desiderata
into one knot.  There is some educated suspicion that doing so
will yield only somewhat material-inefficient and complicated knots,
in contrast to having two (or three) knots not so; that learning to
apply such a complicated knot will be more of a challenge than to
learn the multiple of knots each suited for a specific goal; that having
a different (TIB vs. PET) tying method might as well yield distinct
knots --there is no practical *prize* for getting the same!
(Your closing remarks acknowledge this situation.)

Quote
With particular regard to being TIB, I believe for such a bowline to be considered 'useful'
it would need to be as secure (if not more so) than an Alpine Butterfly Loop
and as quick and easy to tie in the bight (or at least nearly so).
For all practical purposes, I do not see a mountaineer even considering a bowline
as a fixed mid line loop unless it is very easy to tie reliably, is able to be ring loaded,
and has been tested as offering security in suitable climbing type ropes.

While it's a nice quality, what vulnerability do you foresee of
eyeknots NOT stable in ring-loading for mid-line eyes?
(The butterfly might be able to capsize, though if so, it will
likely be into a differently oriented butterfly --i.e., where the
eye legs become as S.Parts were, and vice versa.  (Other of similar
knots --viz., Ashley's bends #1408, 1452-- have this property.)

As for tested as offering security ... , where has that been done
(other than presumed "testing" by usage, or by break tests re
slippage during that one-time heavy loading) ?


--dl*
====
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: Mobius on April 06, 2015, 12:55:21 AM
[S-] I am interested in developing a secure bowline [that] is TIB
[P-] and is very easy to tie in both a PET (end loop) fashion and
[M-] is also able to be used (practically) as a secure mid line loop.
Here we should question the goal of putting all of these desiderata
into one knot.  There is some educated suspicion that doing so
will yield only somewhat material-inefficient and complicated knots,
in contrast to having two (or three) knots not so;

Yes, it also occurs to me that a knot that tries to 'do it all' could easily end up being over-complicated to the point very few could reliably tie it, particularly the TIB bowline forms from my limited experience. I imagine that material inefficiency would not put too many off a knot, however difficult tie-ability certainly would. With particular regard to bowlines: I have noticed from my knot playing, that the PM knots that I have found an easy way to end loop tie are very difficult to tie mid line while the opposite can also be true! I am hoping to find one that is easy to tie mid line and not too bad to get right as an end loop, I think that is an easier objective than the other way around.

Quote
..... that learning to
apply such a complicated knot will be more of a challenge than to
learn the multiple of knots each suited for a specific goal; that having
a different (TIB vs. PET) tying method might as well yield distinct
knots --there is no practical *prize* for getting the same!
(Your closing remarks acknowledge this situation.)

Quote
With particular regard to being TIB, I believe for such a bowline to be considered 'useful'
it would need to be as secure (if not more so) than an Alpine Butterfly Loop
and as quick and easy to tie in the bight (or at least nearly so).
For all practical purposes, I do not see a mountaineer even considering a bowline
as a fixed mid line loop unless it is very easy to tie reliably, is able to be ring loaded,
and has been tested as offering security in suitable climbing type ropes.

While it's a nice quality, what vulnerability do you foresee of
eyeknots NOT stable in ring-loading for mid-line eyes?

I had read (Mark Gommers, 'An Analysis of Bowlines' is one such place) that the basic R-hand bowline is susceptible to ring loading while a Cowboy bowline is resistant to ring loading. This left me with the impression that ring loading was something a bowline should aim for in some applications. I do not see a particular vulnerability, and perhaps because TIB bowlines are more complex than a R-hand bowline, there is nothing to worry about. However, that isn't obvious to me. I would like to test any bowline I came up with for ring loading, just in case.

(The butterfly might be able to capsize, though if so, it will
likely be into a differently oriented butterfly --i.e., where the
eye legs become as S.Parts were, and vice versa.  (Other of similar
knots --viz., Ashley's bends #1408, 1452-- have this property.)

As for tested as offering security ... , where has that been done
(other than presumed "testing" by usage, or by break tests re
slippage during that one-time heavy loading) ?


--dl*
====

"Testing" by usage is the ultimate test, however I would not presume someone first testing any knot that I came up with by jumping off a cliff in a harness to see if it held :) Break tests under slow loads for slippage is certainly a good start, one-time heavy loading is important too. I don't have suitable test facilities to do these things unfortunately. Indeed, many good knots by others probably go relatively unnoticed since nobody has the time (or resources) to facility test them.

For someone with the resources to test a knot I think the knot would have to offer something worthwhile. Either the proposed knot will meet a very specific need, or the knot is a more general purpose 'one size fits all' that is very easy to tie and untie. One of those two things might prompt someone who does have the facilities to test a new knot.

Cheers,

mobius

[my first paragraph is an edit]
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: xarax on April 06, 2015, 04:10:03 AM
  There is some educated suspicion ...

..."educated" suspicion (sic)...
   I try not to start laughing right from the start, because I am afraid I will not make it to the end - alive !  :) :) :)

...material-inefficient and complicated knots......

   The TIB Ampersand bowline, for example, which requires the same amount of material, and the same number of tucks, with any Janus bowline, is, according to Dan Lehman s educated guess, "material-inefficient" and "complicated".
   The same happens with the TIB Pet loop, which requires the same amount of material and the same number of tucks with the Span loop.
   The same happens with the TIB Pretzel loop, which requires less material, and fewer tucks, than his mediocre "quick8" - which does nt seem very TIB to me...
   I could easily go on and on, and compare the "material efficiency" and the tying complexity of those knots with Dan Lehman s "Mirrored bowline", or his two TIB Zeppelin-like loops - the one he did publish, and the other he promised to publish, as soon as my growing beard reaches the floor...
   In sort, TIB bowlines are sour grapes for some knot tyers who had not educated themselves on this subject - and, to blur the issue, they keep singing the same old song again and again, about "multiple knots, each suited for a specific goal"... Yeah, by definition there is an infinite number of specific things, in general, and "specific goals", in particular, and so there is an infinite number of knots suitable for them - so, when one wants to tie something, he should only ask the self-acclaimed "educated" gurus...   
   There ARE TIB bowlines which are as good as, or even better than, any other end-of-line loop - and I would even argue that we already have too many of them !  :)  In my previous posts, I had referred to some - the interested reader can search for them in this Forum and elsewhere, tie and try them - he will only need a piece of chord, and common sense ! Practical knotting is not rocket science, it is a subject no more difficult than arithmetic, for KnotGod s sake - it requires only patience, and, from one level and above, passion. However, I have to point out that a minimum portion of due reference to, and sincere evaluation of, what we already know, and of honesty as well, will make no harm... 
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: Dan_Lehman on April 11, 2015, 06:14:02 PM
[S-] I am interested in developing a secure bowline [that] is TIB
...
[M-] is also able to be used (practically) as a secure mid line loop.

Another point : what do you want as a "mid-line" eye knot?
--just something that is TIB ?!
--or something that can take all possible loadings
(i.p., loading through (end-2-end), and loading the eye
vs. either end?
I don't think that X. has anything bowlinesque that will well
serve the latter need.  (But we can be certain that he can fill
many lines with keystrokes about "understanding" and blah!)

Quote
Quote
Quote
For all practical purposes, I do not see a mountaineer even considering a bowline
as a fixed mid line loop unless it is very easy to tie reliably, is able to be ring loaded,
and has been tested as offering security in suitable climbing type ropes.
While it's a nice quality, what vulnerability do you foresee of
eyeknots NOT stable in ring-loading for mid-line eyes?

I had read (Mark Gommers, 'An Analysis of Bowlines' is one such place)
that the basic R-hand bowline is susceptible to ring loading while a [so-called]
"Cowboy bowline" is resistant to ring loading. This left me with the impression
that ring loading was something a bowline should aim for in some applications.
I do not see a particular vulnerability, and perhaps because TIB bowlines are more
complex than a R-hand bowline, there is nothing to worry about. However, ...
And Mark I think got that news re vulnerability from me, who recalls
reading some hearsay/rumor that some injured-in-fall rockclimber
was attempted to be airlifted out via an attachment to his still
tied tie-in eyeknot, clipping into the eye and ring-loading it,
and ... that turned out tragically.  Perhaps this never occurred,
but one can test the problem and see that it exists --to some degree.
And it's an interesting counterpoint to the labeling of the tail-on-outside
version as being "wrong".  Otherwise, I observed this version in use
on a commercial-fishing trawler's mooring lines, and wondered if
perhaps that was a deliberate variation to the norm on account
of what I also observed (in the Cape May, New Jersey, USA area):
capsized bowlines !!  (I don't know why they get capsized,
but I have seen too many so oriented to dismiss it as insignificant!)

Quote
"Testing" by usage is the ultimate test, however
Well, it is something also to be not dismissed; but one can question
the thoroughness, even so --might some odd danger exist in what
seems an insignificant variation (such as just discussed re bowlines)?!
So, a methodical laying out of possibilities and then some intelligent
testing of them remains part of "ultimate", IMO.  --just building a
good checklist of considerations to note being considered and how
(since exhaustive testing is often difficult, one might "consider"
the condition in light of usage, things known otherwise, all the
while noting that it was not specifically tested).  E.g., consider
a mid-line eye knot being tested : this has been done, I think,
in two ways --through loading (sometimes; so the knot is loaded
qua end-2-end joint), and eve-vs-ONEnd (and in a separate test
specimen, new and *clean*/untainted) !!  Now, in actual-practical
usage, there might be loading that comes one way AND THEN
the other : will first loading reshape the knot such that the 2nd
loading ... at least gets a well different result (weaker, say, or
more disruptive of knot structure) than pure, clinical, testing
had indicated?  (You can see how test cases multiply so much,
even w/o the desired repetition!)

--dl*
====
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: xarax on April 11, 2015, 07:01:13 PM
...something that can take all possible loadings
  I don't think that X. has anything bowlinesque that will well serve the latter need.

  I have not tested, or even tried as extensively as I would had wished, the TIB bowlines I know in that "reversed" kind of loading, that is true.
  However, as a great master of blah-blahing says ( when he imagines he has understood something ), an "educated suspicion"(sic)  :) tells me that there are such loops out there, which can be loaded like this, indeed - but as I had mentioned elsewhere, when they are loaded this way, they behave not as classic bowlines any more, but as crossing knot-based bowline-like loops. Crossing-knot-based PET loops have not attracted the attention they deserve, IMHO, so we just do not have enough information about them to predict their properties under heavy loading...
  Try the ones I propose, the Ampersand bowline and the Pet loop, and tell me what you see.
  The real master of the bowline-like knots we are lucky to have in our Forum, who is not talking/blah-blahing because he is doing, Alan Lee, has not only tied dozens of dozens secure, neat and very original such loops, but has tried some of them as well. Perhaps he can tell you more about this interesting issue.
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: alpineer on April 11, 2015, 07:33:24 PM
  (But we can be certain that he can fill
many lines with keystrokes about "understanding" and blah!)
 

 alpineer likes this
 

 
 
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: Mobius on April 13, 2015, 12:30:54 PM
Another point : what do you want as a "mid-line" eye knot?
--just something that is TIB ?!
--or something that can take all possible loadings
(i.p., loading through (end-2-end), and loading the eye
vs. either end?

I have hopes of finding a knot that is TIB and can be loaded end-2-end (e2e) or eye to either end (i2e). I have a bowline that I have been playing with in several different formats that I think is new. It is PET, TIB, easy to tie TIB (3 main easy steps that do not involve nefarious twists), fairly easy to tie as an end loop (7 pretty easy steps (harnessed on a cliff with finger gloves on perhaps), vs 4 similar steps for a R-hand bowline as a comparison) and is potentially secure under e2e, or i2e loads. The twin collar structure looks easy to untie as well, even after heavy loading. Also, the curves entering into/within the nub all look 'gentle' to me. So theoretically, it might be a good bowline.

I am quite keen to do my own trials on it first before releasing it here for critique (ridicule perhaps  :P ). My trials might only go as far as seeing if the knot collapses under strain (something a lot more than me just tugging on the knot furiously with all my might ;) ) and if it is easy to untie after load. If the knot looks promising to me I'll share it with the forum.

Quote
"Testing" by usage is the ultimate test, however
Well, it is something also to be not dismissed; but one can question
the thoroughness, even so --might some odd danger exist in what
seems an insignificant variation (such as just discussed re bowlines)?!
So, a methodical laying out of possibilities and then some intelligent
testing of them remains part of "ultimate", IMO.  --just building a
good checklist of considerations to note being considered and how
(since exhaustive testing is often difficult, one might "consider"
the condition in light of usage, things known otherwise, all the
while noting that it was not specifically tested).  E.g., consider
a mid-line eye knot being tested : this has been done, I think,
in two ways --through loading (sometimes; so the knot is loaded
qua end-2-end joint), and eve-vs-ONEnd (and in a separate test
specimen, new and *clean*/untainted) !!  Now, in actual-practical
usage, there might be loading that comes one way AND THEN
the other : will first loading reshape the knot such that the 2nd
loading ... at least gets a well different result (weaker, say, or
more disruptive of knot structure) than pure, clinical, testing
had indicated?  (You can see how test cases multiply so much,
even w/o the desired repetition!)

--dl*
====

I see your point. There are knots used 'successfully' everyday, that are potentially unsafe when they encounter the untoward (uncommon) circumstances that cause them to fail (perhaps at the cost of a life). Clinical testing seems to be a rarity in the knotting world, and I say that hoping not take anything away from those who have taken the time and effort to do some fine trials/comparisons.

Cheers,

mobius

[edit: fixed some typo's and sloppy writing]
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: agent_smith on April 13, 2015, 12:57:44 PM
Quote
And Mark I think got that news re vulnerability from me, who recalls
reading some hearsay/rumor that some injured-in-fall rockclimber
was attempted to be airlifted out via an attachment to his still
tied tie-in eyeknot, clipping into the eye and ring-loading it,
and ... that turned out tragically.

If I can see further its because I have stood upon the shoulders of giants.  Hmmm, which famous man said that?

Ring loading is a known vulnerability of #1010 (right hand bowline).

Many vertical rescue technicians use and rely on a bowline as the principle interface knot connecting stretcher (ie litter) to haul ropes.   #1034 1/2  (left hand Bowline) is resistant to ring loading vulnerability.

Bowlines are also commonly used in rock climbing and mountaineering applications. Indeed, old photos of Sir Ed Hillary show him using a Bowline as a tie-in knot (Note: Crucially - or luckily - they used hawser lay vegetable fibre rope in those days which had a rough/frictive exterior - and that property of the rope likely saved many climbers from catastrophic knot failure). These days of course, we use synthetic fibre ropes of a Kernmantel (German spelling) construction - its slick and slippery and a Bowline in its standard form (#1010) will not be secure and stable.

Hence, sensible/informed climbers who choose to use a Bowline will take counter-measures to secure the #1010 structure in some way.

I personally always use the EBSB Bowline variant - and have done for several years now - and have tested the EBSB structure in real-world circumstances (I'm a climber). As I am typing this post, it is evident that I am still alive  - so therefore the EBSB variant has proven capability and is fit for purpose. NOTE: Others use the EBSB too - I'm not alone. I am what is loosely known as a 'trad' climber. I like to 'on-sight' new routes by climbing them ground-up without prior rehearsals or inspections. I lead the new routes using removable protection devices. I risk taking BIG falls - and the tie-in know of choice for me is the EBSB. Indeed, I have taken several significant leader falls and the EBSB did not fail, or become unstable or insecure in any way. I like it because the tail is held firmly in 2 places and, being as Bowline derivative, it is easy to untie after high loading events.

The EBSB variant was inspired by Dan Lehman's EBDB creation.

...

Having said all that, I would be VERY interested to learn more about Mobius creation.

Quote
I am quite keen to do my own trials on it first before releasing it her for critique (ridicule perhaps  :P ). My trials might only go as far as seeing if the knot collapses under strain (something a lot more than me just tugging on the knot furiously with all my might ;) ) and if it is easy to untie after load. If the knot looks promising to me I'll share it with the forum.

I would like to include it in my next update of the Bowline Analysis document. In that document, I will also be adding information about knot terminology with clear photos illustrating the terms (ie turn/loop/strangle/slipped/underhand/overhand/ etc...).

Also hoping to enlist Dan Lehman and Xarax and anyone else that can assist because my ambition is to make it the definitive resource on the Bowline for all to use in the public domain. You might say that it is on my bucket list of things to do before I die to get the Bowline Analysis document as close to perfect as I can (if such a goal is indeed even possible!).

Mark



Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: xarax on April 13, 2015, 01:23:35 PM
As I am typing this post, it is evident that I am still alive

   :) :) :)

... my ambition is to make it the definitive resource on the Bowline for all to use in the public domain. You might say that it is on my bucket list of things to do before I die to get the Bowline Analysis document as close to perfect as I can (

  Please, do it before I, too, die !  :) :) :) If you continue at the present pace, I will be forced to live for centuries !  :)
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: Mobius on April 13, 2015, 03:52:04 PM
The EBSB variant was inspired by Dan Lehman's EBDB creation.

...

Having said all that, I would be VERY interested to learn more about Mobius creation.

Mark

Another knot (2 nipping turns, 2 collars): I also have a "Dan Lehman's EBDB style bowline (with an extra 'yobo' tuck, Dan will love that aspect I'm sure :) ). I came upon this knot independently (and it is not just a re-tucked EBDB) that is PET and TIB. The trouble with this particular knot is that the tie method for TIB sucks IMHO. Perhaps it is just me, however if I have to mentally struggle to remember to twist numerous times in the right direction, create a loop, or two (in the appropriate helix structure), pass a bight through a loop structure with the right twist, it is simply all too hard to bother with (even when the knot can be laid out flat in front of me).

The first knot I mentioned previously doesn't suffer from that defect I believe. It is more complex on one level since it has more structure (2 nipping turns and 3 collars), however it is very easy to tie TIB.

Anyway, thanks for your supporting comments Mark. I'm now spurred on to test my knot(s) further :)

Cheers,

mobius
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: Mobius on April 14, 2015, 07:08:49 AM
  Do you really believe that the method of tying the Girth hitch-based TIB bowline involves "nefarious" twists ?  :) :)

That knot is easy to tie TIB in 2-dimesions, that is obvious from the given pictures. Unfortunately, what is not obvious is how one is supposed to tie it in an easy manner when the comfort of a flat surface is not available to set out our knot as shown. Eg. when we are 10m up, leaning against a ladder while standing on one of it's rungs. Equally unfortunate is that several TIB knot tying methods shown on this forum, or other sites, seem to rely on a flat working surface to make them work! Also, even with the benefit of a flat working surface some of them are full of nefarious twists ;)

Now for the good news, the Girth hitch-based Bowline can be tied in a nice manner in 4 main steps without any surface to work on, but xarax probably knew that already :) So the knot appears to be a very good one: PET, TIB, easy to tie.... and no.... it does not require nefarious twists when tied in the TIB fashion I used.

BTW, I prefer the version of this knot where the eye is reeved through the collar in the opposite direction. The knot you end up with is one where the two nipping loops seem to stay together and the knot seems to snug better. Maybe a matter of taste.
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: xarax on April 14, 2015, 02:54:01 PM
  There is something "in" the object we call a "knot" per se, which contributes to the easiness we can handle it mentally, in our mind s 2D "screen" : the representation and the transformation of knots becomes very simple and unambiguous, when the knot is spread out in a 2D real or imaginary "flat surface", and all crossing points are crossing points of two, and two only, lines. The same happens in mathematical knots : To represent their knots, mathematicians use "flat" diagrams, where all crossing points correspond to two, and two only, overlapping lines at each point, although their "lines" are supposed to be infinitely stretchable, and they could had used any "curved" and tangled representation they had wished. 
   So, it seems that there is something "in the knots", or, at least, "in our mind", which makes us represent the loose knots on a 2D surface, that is, as been "flattened out". Of course, a finished 3D knot can be loosened and then squeezed on any 2D flat surface we wish, there is no "preferable", intrinsically determined orientation to do this. However, there will always be one orientation from which a projection of the compact 3D knot on a 2D surface will have a maximal area cross section, and one from which such a projection will have a minimal area cross section. From this one orientation the knot will look more "flat", and from the other one it will look more "globular". We chose to select the former and call the view from it "front" or "rear" , and prefer to represent the loosened or the compact knots in this orientation, simply because when the cross section becomes larger, the distance between any two crossing points become larger, too, and the possibility to have "ambiguous" crossing points with three or more lines overlapping each other becomes smaller.
   This means that our choice of the "flat" "front/back" view is not as arbitrary as one might think it is... There are some knots where, initially, it is arbitrary, indeed, when the knot is axially symmetric - as the beautiful Diamond bend and PET loop is, for example :                                       
   http://igkt.net/sm/index.php?topic=5151.0
   However, if we chose to project the pair of the Standing/Tail Ends so that the two lines do not overlap each other, they are not "over" or "under" each other, but "side by side", the one next to the other, we get a preferred orientation for those knots, too ( see the attached picture ).
   http://igkt.net/sm/index.php?topic=5151.msg33744#msg33744

   In short, all knots, in their loose or their most compact form(s), can be represented on one more or less preferable "flat" surface, and the fact that such a surface may not be actually/physically available, "at hand", does not mean that it can not be mentally available, in "the mind s eye". It is this surface which helps us remember and manipulate the knots, more than anything else. When a climber ties and unties a knot, he should be able to do this when he wears gloves, and his ropes and fingers are almost frozen, and in the dark, and hung upside down, and behind his back !  :) :) There is no flat surface anywhere close - but there is always a flat representation of those knots in his mind, without which he can do nothing at all. See all representations of the fig.8 knot : they are flat, and moreover they are flattened by been spread out on a surface of always the same orientation, although the fig.7 knot is a complex convoluted 3D shape, which could had been viewed from any angle. Do you always carry this 2D surface in your brain s luggage ? Then do not be afraid of the absence of the table you forgot at home...  :)   
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: Tex on April 14, 2015, 03:46:14 PM

I started this post to say that I love how the retraced bowline tied PET or TIB (I'm picking up the lingo here) is beautifully easy to verify.  Even if you've never seen one before you can tell in an instant that it's not tied wrong.

It's pretty easy to tie (if tedious) to tie and you can even do it one handed.

Obviously as pointed out, it's inefficient, especially if you need a large loop, and under pure ring loading with standing ends loose, it seems still like the wrong knot to me.

Do you guys who like testing knots by tying them to your waist and falling off rocks trust it? (Only answer if you're still alive)

I don't love fixing basic bowlines or crazy variations of bowlines because there are so many crazy fixes out there and many aren't so beautifully obvious and the Yosimite even seems at least as scary as no fix at all. 

... but then I saw that girth hitch bowline and I have to say it's kind of neat, and yes, easy to tie, even if not quite as easy to verify. 






 
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: Tex on April 15, 2015, 03:19:51 AM
It seems I wasn't clear.  I meant this:
http://www.animatedknots.com/bowlinebight/

So there are three differences between that and xarax's girth hitch bowline.

1) the girth hitch instead of the half-hitch nip
2) using 1 side of thee loop to tie the hitch instead of both sides (I'll call this one sided vs two sided)
3) and this not exactly topological but possibly very important, pulling one of the two main loops up tight into the knot which the girth hitch as shown does and the one in the link doesn't which is why one has a single main loop and the other a double.   (I'll call this single or double looped)
   
What's neat is you can apply, independently any combination of the 3 differences.

-A one sided single looped half hitch version becomes a slip knot, and the double looped one is messed up because it's like a slip knot and a bowline side by side.

-however a two sided single looped half hitch version  (so the one in the link put pulling in one of the main loops)  seems to me pretty ring-load resistant, but just initial feeling.

-a two sided girth hitch seems pretty fine on initial impression, maybe regardless of single or double looped.

I haven't played with them much.



Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: Tex on April 15, 2015, 03:53:23 AM
I messed that up a little. 

Either of the single sided double loop combos make a slip knot plus a bowline.  In either case if you pull up the slip side you're back to a single sided single loop version for both hitch styles.  But that pulled up loop maybe isn't buying you much for ring loading because it slips straight through to one of the tails.  It's not hurting either though.

The pulled up loop maybe only buys you extra in the double sided versions, where it then makes an extra nip that's tugged by the other loop.

Anyway the double looped versions only make sense for the double sided nips.


(edit: So apparently I didn't understand PET, oh well)
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: Tex on April 15, 2015, 05:54:46 AM
and not surprisingly xarax and others have been over this stuff before:

http://igkt.net/sm/index.php?topic=4687.0

.. and to me it all comes back to the visual clarity of the retraced bowline.
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: xarax on April 15, 2015, 10:19:51 AM
   The bowline in, on or upon the bight is a beauty, no question about that. The "clarity of the retraced bowline", as you describe the simplicity of its form and method of tying it in-the-end, AND the "haltering/haltered collar" method of tying it in-the-bight ( ABoK#1080), make it one of the great knots we have.
   ( Now there is a vacant seat in my pantheon of "old" knots (1), I wonder if I should offer it to this double loop, which can easily be transformed into a secure single TIB bowline that can be loaded by both ends, or by any of its ends, as you say... :) )

1.  http://igkt.net/sm/index.php?topic=1150.msg33735#msg33735
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: Mobius on April 15, 2015, 10:29:19 AM
...when the comfort of a flat surface is not available to set out our knot.

  I have a "lines filling", by "keystroking"  :), comment on this : The "flat surface" is not required for our hands and fingers, to actually help us manipulate the ropes, but for our mind, to help us visualize and memorize the form of the loose and/or the compact knot and the sequence of the required tying moves - and, fortunately, our mind has evolved in a way that made it extremely capable to do this....

Yet again, another thoughtful response to one of my posts, thank you xarax :)

I don't think my knotting mind 'evolution' has taken place yet ;) Some 2-dimensional diagrams are fine for helping us tie in the 3D world, others are simply not. For example, I recently learned to tie the Double Dragon. A 2D representation of the knot given just prior to the final collar tuck is fine for me as a tying method. I believe it translates well from 2D to 3D.

Now let's consider the 'b' 'q' method of tying a Zepplin bend. In 2D world it is easy (I am referring to using a table to lay the knot out on), in 3D world the forming of the knot is a little more awkward: ie. Make the correct helix 'b', hold on to it while nipping the other reverse helix 'q' into the right place. Then pass the ends through the loops in opposite directions. I don't even think this knot is particularly hard to do 'in the hand' with this same method, however I am sure it is already past the capabilities of many people who tie knots just occasionally.

Now for a method that has been labeled as "easy" in 2D world and the reality is that the best way to tie the knot 3D bears little more than a passing resemblance to the 2D depiction of it. On top of that, one is left trying to find a reasonable tying method and thinking to oneself, "I must be stupid, this isn't easy"  ;D

It is this surface which helps us remember and manipulate the knots, more than anything else. When a climber ties and unties a knot, he should be able to do this when he wears gloves, and his ropes and fingers are almost frozen, and in the dark, and hung upside down, and behind his back !  :) :) There is no flat surface anywhere close - but there is always a flat representation of those knots in his mind, without which he can do nothing at all. 

I could not disagree more. I am not a climber, however the last thing I would think about (if I was tying a knot on some mountain side) would be what the 2D knot looked like (ie. one laid out on a table top). What I would be thinking about is the steps I have practiced to hold the knot properly in my hands and do the appropriate turns and tucks. These two approaches are quite different I believe. As a personal and hopefully somewhat relevant example: I recently started playing with string (rope) again and realized that the children's knot shapes (teacups, rocket ships, etc) I thought I had long forgotten were still there, "in my hands". What helps us remember knots is not a 'surface', it is manual dexterity and practice. I believe our hands can 'remember' things we didn't even know we knew  8)

Please do not think I am belittling anyones usually fine efforts at showing us (the forum) one-off tying diagrams. Some do exactly what they are supposed to, show us how to tie the knot in 3D and that is because those images happen to translate well. Other images, simply do not translate well into 3D for me; unless I grow an extra hand perhaps ;)

Cheers,

mobius

[edit: changed the mistyped 'p' to 'q' ... that, strangely enough, is also a common tying problem I believe]
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: Mobius on April 15, 2015, 01:25:54 PM
BTW, I prefer the version of this knot where the eye is reeved through the collar in the opposite direction.
...Maybe a matter of taste.

  Now you have raised the bar, and demand a TIB loop which should be able to be loaded by both ends, or by any one of them, we, too, should pay attention to reeve the bight ( which is to be "haltered", and become a collar ) through the direction which leads to suitable such loops - that is, loops where both ends leave their nubs towards the same side, "upwards".

Yes, the pictures xarax shows later are the version I liked. Note that the nipping loops are shown apart (for picture clarity) though they snug together quite nicely with a little dressing.
Title: Re: How to improve the security of the bowline. Two simple instructions.
Post by: xarax on April 15, 2015, 01:57:52 PM
   Another, more "knotted" Pretzel base - which also looks like the real pretzels !  :)
   It can be tied by the same "haltering/haltered collar method" as easily as the other one - only you have to use some more "nefarious" twists  :) (1). I am not sure if this more convoluted / complex nipping structure grips the penetrating lines more effectively. I believe that some complexity may be beneficial, in order  to obtain an intergraded, compact nub, but we should always be very cautious to avoid the overkill, and be left with redundant segments encircling other segments, and sheltering/protecting, instead of squeezing, the penetrating leg(s) of the collar(s).

1. http://igkt.net/sm/index.php?topic=4464.msg33112#msg33112