Author Topic: What defines a Bowline? - structure, characteristics, topology  (Read 144111 times)

xarax

  • Sr. Member
  • *****
  • Posts: 2781
Re: What defines a Bowline? - structure, characteristics, topology
« Reply #105 on: July 31, 2011, 06:05:24 PM »
any definition you want for your bowlines

"My" bowlines ? ? "Yours" are different/bigger ?  :) :)

I really don't mind at all.

   Well, I can reply to this evaluation of my efforts to try to understand what the bowline is - not "my" bowline, not even yours... :)- by the infamous Knot4u dictum : "I think I can live with this..."
This is not a knot.

DerekSmith

  • IGKT Member
  • Sr. Member
  • *****
  • Posts: 1530
  • Knot Botherer
    • ALbion Alliance
Re: What defines a Bowline? - structure, characteristics, topology
« Reply #106 on: July 31, 2011, 06:19:01 PM »
snip...

This is not a discussion of what is truth about a Bowline, but I see it as a tentative to do some classification of a group of knots that are supposed to belong to a family, which should be further defined. In such classification it may have some merit to be very strict, but there might also be reasons for a more lax attitude. After all, whether science or not, the issue is not falsifying any knot that is named Bowline, but rather trying to find common treats if we find it fruitful to classify a certain order of knots as belonging to the bowline family.

snip...

snip...

In any case, I don't find the consideration of loading to
sacrifice objectivity.
(But there are certainly fuzzy boundaries, as have been noted,
in shifting geometries coming with vagaries of dressing.)

--dl*
====

"What defines a Bowline?"

At one extreme we have a single knot - #1010 (in the left hand and right hand variants)

www.motorboatsmonthly.co.uk

"ABoK 1010. The BOWLINE, BOWLING, or BOLIN KNOT, sometimes called
BOWLING's KNOT. The name is derived from bow line, a rope that
holds the weather leech of a square sail forward and prevents the
sail from being taken aback. As the line or rope that provided the
knot is no longer in use, the BOWLINE KNOT is nowadays very apt to
be termed merely the "BOWLINE," the word knot being dropped."

An alternative definition of this one knot, based upon its active components is - A loop knot made with two active components - A bight component (sometimes referred to as a collar) - and a nipping loop which ranges with loading from a simple hitch component to a half hitch component.  As the normal loop mode is for legs to be loaded roughly 50/50, I believe my original definition of simple hitch component should be amended to Half Hitch Component (HhC).

-----------------------

The other end of the spectrum of definitions is - The Bowline is a Loop Knot...

And yes, we have all seen a host of loop knots - rightly or wrongly - called a Bowline or an XYZ Bowline.  I have even seen the Overhand TIB loop called a 'Bowline' (meaning - loop knot, or simply - LOOP).

----------------------

Then, in between these extremes, there are knots which hold a strong similarity to #1010 in terms of components, functionality, etc. and others which simply seem to have a 'lookalikeness', tying method, or historical naming reference etc.

How can we pull any sense or consensus out of a muddle that has been hundreds of years in the making?  Because the situation is such a mess, only taking an extreme stance is likely to make any sense.  We could make the rather inane modern response of "Whatever" and leave it all as it is and let it continue to fester.  Or we could make the drastic stand that ONLY #1010 is a Bowline and some 're-tucked' variations are 'Security extensions', but not really genuine Bowlines.  The problem of moving to any other cut off point is - where to draw the line - and that really is so subjective as to warrant the apt situation of 'how long is a piece of string?'

NB.  I have looked at the Eskimo, and indeed, (by my offered definition) it is NOT a Bowline because it contains a Bight Component and a Carrick Component, instead of the necessary Bight Component and Half Hitch Component.

@ Dan, I addressed your Myrtle question back at the end of post #70.  By my proposed definition, it is NOT a Bowline because it contains a Simple Hitch Component and a Turn Component - i.e. it is also lacking the Bight Component.

Derek

xarax

  • Sr. Member
  • *****
  • Posts: 2781
Re: What defines a Bowline? - structure, characteristics, topology
« Reply #107 on: July 31, 2011, 07:01:06 PM »
   I have tried to figure out something that can serve as a simply and unambiguously defined distinctive feature that will separate the nipping loop of the bowline, from the nipping loop of the Karash loop...other than the Dan Lehman s somewhat vague "direct / indirect eye feed" feature . No luck. The closest thing I could think of is a distinction based upon the inclination of the plane of the nipping loop, in relation to its ends. The most effective nipping loop is the flat one, where the two ends and the bight are on the same plane. Then, the nipping power of the nipping loop, on any line(s) that passes through it, is maximum. As the nipping loop gets more "twisted", and its plane more inclined, it is nipping the line(s) that pass through it less effectively - because some tension is "wasted" on friction around the crossing point of the two ends. When it makes a 180 degrees twist, we have a pure crossing knot. Somewhere in between, the pure nipping loop is turned into a nipping loop/crossing knot hybrid, and, at the very end, into a pure crossing knot. Where ? I have no idea...We have to measure the nipping power on the mainline(s) that pass through it, and see if there is a point of maximum rate of nipping power deterioration...From then on, we should speak of a crossing knot, not a nipping loop, and exclude from the bowline group the end-of-line loops that are based upon such crossing knots.
   Not a very simple nipping loop / crossing knot distinction, I am afraid... :)
   Ashley uses the term "crossing knot" in a number of ways. He will not hesitate to call "crossing knot" the Clove hitch and the Constrictor, as well as many other hitches around poles. He shows the "common" Crossing knot at #206, #365,  #1071-1074, #2077, #2090. The  knot shown there is a little different from the "twisted nipping loop" of the Karash single loop, (shown in the attached pictures), but there is no doubt that there is some similarity, indeed, that enables us to characterize this loop as a crossing knot, or part of a crossing knot. It is not difficult to see a hitch there, at the end/leg of the nipping loop that makes a right turn around the other, i.e. to see the crossing knot as a "nipping loop + hitch" compound knot.
   Incidentally, I have discovered a point where the great Ashley makes the same mistake as Derek Smith :) : At ABoK#1420, he describes the Double Harness bend as a compound of two crossing knots, when it is clearly the compound of two hitches - the tails of those hitches are not loaded, as they should, were they crossing knots.(See the third attached picture)
« Last Edit: July 31, 2011, 07:12:38 PM by xarax »
This is not a knot.

xarax

  • Sr. Member
  • *****
  • Posts: 2781
Re: What defines a Bowline? - structure, characteristics, topology
« Reply #108 on: July 31, 2011, 07:37:44 PM »
   Derek, you keep publishing the same picture, over and over again, as a picture of a bowline, when it could well be a picture of a Sheet bend! If a bowline is loaded, ( 50/50, or else), it can not resemble this picture. The sheet bend can, be it loaded or not. This picture might be a picture where the one end goes to the St Peter s church in the Vatican, the Great Wall, the Great Barrier reef, you name it, and then returns and pop up itself again, as the second leg of the eye of a bowline ! So, based on this misleading picture, you believe that there is some relation between the bowline and the Sheet bend, while the picture itself proves that there is none ! The bowline is a knot where three (3) ends are loaded, while the Sheet bend is a knot where only two (2) ends are loaded! Big, Huge difference. You are talking about of "Forces" and all that, and you are ready to compare two completely different structures, because, WHEN THE ONE IS NOT LOADED, it superficially resembles the other, that might be loaded or not !  :)
   Derek, you are confused here... :), but I do appreciate your efforts ! The last elimination of the Eskimo bowline from the group of bowlines would make Dan Lehman happy...but it will not change its name, I am afraid, neither its other features, which are similar to the common bowline.  
  
« Last Edit: July 31, 2011, 07:38:45 PM by xarax »
This is not a knot.

[Inkanyezi] gone

  • Sr. Member
  • *****
  • Posts: 340
    • Pro three strand splice
Re: What defines a Bowline? - structure, characteristics, topology
« Reply #109 on: July 31, 2011, 08:35:34 PM »

(snip/
"What defines a Bowline?"

At one extreme we have a single knot - #1010 (in the left hand and right hand variants)

www.motorboatsmonthly.co.uk
/snip/

The problem with the image is that it does not depict a Bowline in use, but is a schematic view that shows how to correctly tie one.

The bowline ideally should be loaded equally on both legs of the eye almost in line with the standing part. The nipping turn then takes the form of a turNip, which is different from the nipping structure in the sheet bend. The forces that oppose the spiral of the nipping turn to open come mainly from one of the loop legs, the one that returns through the nip, and the collar U-turn that holds against the standing part, with the end returning through the nip. Below is an image thought to illustrate the Bowline works. A substantial difference is that the continuation into the eye leg from the standing part after taking the turn is not nipped by the standing part, but it is the load on the eye that holds the nip in the turn.
« Last Edit: July 31, 2011, 08:44:51 PM by Inkanyezi »
All images and text of mine published on the IGKT site is licensed according to a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
http://creativecommons.org/licenses/by-nc-sa/3.0/

xarax

  • Sr. Member
  • *****
  • Posts: 2781
Re: What defines a Bowline? - structure, characteristics, topology
« Reply #110 on: July 31, 2011, 08:36:54 PM »
   @ Derek Smith : See the three attached pictures. The first is of a loaded bowline, tied around a large diameter object. The second and the third are of a (loaded or not, does not matter) Sheet bend.
   If you insist to see similarities in knots, regardless of how many, and which, ends are loaded or not, as you do in the case of the common bowline and the Sheet bend, why THOSE two knots are different ? Why you say that the same hitch structure, that is present in the Sheet bend, is not present in the Eskimo bowline ? The pictures tell a different story...
This is not a knot.

DerekSmith

  • IGKT Member
  • Sr. Member
  • *****
  • Posts: 1530
  • Knot Botherer
    • ALbion Alliance
Re: What defines a Bowline? - structure, characteristics, topology
« Reply #111 on: July 31, 2011, 11:12:11 PM »
  @ Derek Smith : See the three attached pictures. The first is of a loaded bowline, tied around a large diameter object. The second and the third are of a (loaded or not, does not matter) Sheet bend.
   If you insist to see similarities in knots, regardless of how many, and which, ends are loaded or not, as you do in the case of the common bowline and the Sheet bend, why THOSE two knots are different ? Why you say that the same hitch structure, that is present in the Sheet bend, is not present in the Eskimo bowline ? The pictures tell a different story...

No, the first is a beautifully laid out image of a circular - UNLOADED - Eskimo bowline that you have previously presented to us.

No, the second is a core - it is not a working knot as it has no input and output loading assigned to any of its four legs.

Yes, the third image is indeed as you state a sheetbend (probably unloaded or only lightly loaded)

Could you now please restate your question ?

--------------------

@ Inkanyezi

What is this?


I guess that before we can get down to defining a Bowline we have to reach some agreement on how a Bowline should be dressed and set.  I have climbed on the bowline for a number of years and I would NEVER have dreamt of climbing on a knot so shoddily dressed.  I have however seen knots at the waterfront where the collar has been hugely distended and the half hitch has rotated to nothing more than a turn.  I had always assumed that these (to me failed) examples were either the toll of time or just shoddy knotcraft.

Now I have to ask in all seriousness - Is this how you nautical types genuinely dress and set the Bowline?

Sorry to everyone for going backwards here, but we need to be sure that we are in fact talking about the same constructions, and certainly, this 'Bowline' that Inkanyezi is promoting is like no Bowline I would ever have made.

Derek

DerekSmith

  • IGKT Member
  • Sr. Member
  • *****
  • Posts: 1530
  • Knot Botherer
    • ALbion Alliance
Re: What defines a Bowline? - structure, characteristics, topology
« Reply #112 on: July 31, 2011, 11:36:03 PM »
snip...
   Incidentally, I have discovered a point where the great Ashley makes the same mistake as Derek Smith :) : At ABoK#1420, he describes the Double Harness bend as a compound of two crossing knots, when it is clearly the compound of two hitches - the tails of those hitches are not loaded, as they should, were they crossing knots.(See the third attached picture)

Hi Xarax,

While we are waiting for a resolution of 'How to dress a Bowline', could I just pick up on the comment you made about #1420



Technically, although I have used common names for some of the components ( such as Half Hitch Component, Simple Hitch Component...) - none of the components are knots, so they are neither hitches, bends, nor anything comprehensible in the world of complete (i.e. functional) knots.

So I would agree with the Ashley description, except that I would say that the crossing knot is in fact the Carrick Component, and so #1420 is a bend created by combining two Carrick Components

Derek

xarax

  • Sr. Member
  • *****
  • Posts: 2781
Re: What defines a Bowline? - structure, characteristics, topology
« Reply #113 on: August 01, 2011, 12:44:10 AM »
the first is a beautifully laid out image of a circular - UNLOADED - Eskimo bowline that you have previously presented to us.

  Take a beautifully laid out picture of a LOADED bowline, tied around a large diameter object. It would resemble to this picture 99.99%.

the second is a core - it is not a working knot as it has no input and output loading assigned to any of its four legs.
the third image is indeed as you state a sheet bend (probably unloaded or only lightly loaded)

  Take a a beautifully laid out picture of a, loaded or unloaded, Sheet bend. It would resemble to those two pictures 99.99%.


  Now, compare those two sets of pictures, like you had compared the UNLOADED common bowline picture, with the (loaded or unloaded ) Sheet bend picture.
   Do you see any difference ? If you do, how do you manage to do this NOW, and you have not been able to do the same PREVIOUSLY, when you had presented the misleading, unloaded common bowline picture, and the Sheet bend picture, to show/prove that the knots those superficially similar pictures represent, are related ? Why were the common Bowline and the Sheet bend related, and the Eskimo bowline and the Sheet bend are not ?

 
you are ready to compare two completely different structures, because, WHEN THE ONE IS NOT LOADED, it superficially resembles the other, that might be loaded or not !  :)

...but you do this to "prove" only the theory about the supposed common bowline-Sheet bend relation, and you forget to do the same with the Eskimo bowline-Sheet bend relation ! So, you try to eliminate the Eskimo bowline from the bowline family, when this bowline has exactly the same superficial resemblance with the Sheet bend, that the common bowline has with the same bend ....The same resemblance with the same knot, the Sheet bend, can lead you to altogether different classifications of those two knots, the common bowline and the Eskimo bowline ! A Janus miracle !
   You should not compare the superficially pictorial characteristics of the three-loaded-ends common bowline, with those of the two-loaded-ends Sheet bend, as arguments in favour of a supposed relation between the common bowline and the Sheet bend. However, if you do this, as you have already done, you should be consistent, and do the same in the case of the Eskimo bowline and the Sheet bend. I have shown to you pictures that can help you to do this. And if you do this, you will see that there is no more difference between the Eskimo bowline and the Sheet bend, than between the common bowline and the Sheet bend. If you call bowline the former, you should do the same with the later...unless you owe Dan Lehman a Huge amound of worthless US dollars !  :)

   Could you now please restate your answer ?  :) Because, if you continue to insist that the common bowline is related to the Sheet bend, while the Eskimo bowline is not, and the Eskimo bowline should be renamed to Eskimo loop, you are wrong in the first answer, inconsistent in the second, and naive in the third !  :)
« Last Edit: August 01, 2011, 05:33:19 AM by xarax »
This is not a knot.

xarax

  • Sr. Member
  • *****
  • Posts: 2781
Re: What defines a Bowline? - structure, characteristics, topology
« Reply #114 on: August 01, 2011, 01:11:55 AM »
I would agree with the Ashley description

   As Ashley is mistaken on this - because those two structures that form the Double Harness bend are not crossing knots, but hitches, and you are also mistaken to consider that the bowline incorporates a hitch component, it is only natural that you agree with him !  :)

#1420 is a bend created by combining two Carrick Components

   However, I , too, agree with you on this !  :) (even if Ido not know exactly what you mean by this cryptic "Carrick Component"...I decipher it as "the hitch component incorporated in the Carrick loop" we were talking about the oyjer day - or in the Carrick bend.) The ABoK#1033, the Carrick bend, the Angler s loop, all those knots do have a hitch component, indeed, they have segments of standing part lines perpendicular to each other, crossing knot components, etc...in fact, all those things that are  completely absent in the bowline !  :)
This is not a knot.

[Inkanyezi] gone

  • Sr. Member
  • *****
  • Posts: 340
    • Pro three strand splice
Re: What defines a Bowline? - structure, characteristics, topology
« Reply #115 on: August 01, 2011, 06:09:18 AM »
@ Inkanyezi

What is this?


I guess that before we can get down to defining a Bowline we have to reach some agreement on how a Bowline should be dressed and set.  I have climbed on the bowline for a number of years and I would NEVER have dreamt of climbing on a knot so shoddily dressed.  I have however seen knots at the waterfront where the collar has been hugely distended and the half hitch has rotated to nothing more than a turn.  I had always assumed that these (to me failed) examples were either the toll of time or just shoddy knotcraft.

Now I have to ask in all seriousness - Is this how you nautical types genuinely dress and set the Bowline?

Sorry to everyone for going backwards here, but we need to be sure that we are in fact talking about the same constructions, and certainly, this 'Bowline' that Inkanyezi is promoting is like no Bowline I would ever have made.

Derek

Of course this is not what the Bowline would ever be dressed like, but I first tensioned it, and then opened it, so that the parts should become more visibly separated. unfortunately we cannot se three-dimensional images on the screen.

What I try to point out is that whichever way you try to dress the bowline, when it is in use, the nipping turn takes a spiral form resembling that of the Gleipnir, and the forces within the central part of the knot are different from the Sheet Bend. When the Sheet Bend is loaded, the free end of the hitch points at an oblique angle somewhat in the direction of its own standing part, while the collar nips it against its standing part. The Bowline on the other hand does not nip the similar part in the same way, but it is almost in line with the standing part. The "knot" in the image is deliberately opened, so that the collar is very loose, but it is to show the works of the knot, its central feature, the nipping loop, that is almost straight, almost in line with the standing part.

The Bowline always takes that form under load, when heavily loaded or with the load repeatedly applied. Even when you dress it very neatly, if the load is heavy, the bight that forms the collar will be drawn out a little and the former HH made in Sheet Bend fashion will form a turNip. Provided the two legs of the eye are not too widely apart, it will not collapse further.

A neatly dressed Bowline will be snugger, but I eased the bight of the collar, so that the turNip should be more clearly seen.

Post Edit: Below I inserted a photo of a Bowline that was first beautifully dressed, just as in the Motorboaths Monthly image, but then was exposed to heavy stress by loading it with repeated jerks. Invariably it takes the "sloppily dressed" form, drawing out the collar and orienting the nipping turn almost parallel with the standing part. Note the direction the end takes. This is typical for the Right-handed Bowline.
« Last Edit: August 01, 2011, 11:44:51 AM by Inkanyezi »
All images and text of mine published on the IGKT site is licensed according to a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
http://creativecommons.org/licenses/by-nc-sa/3.0/

xarax

  • Sr. Member
  • *****
  • Posts: 2781
Re: What defines a Bowline? - structure, characteristics, topology
« Reply #116 on: August 01, 2011, 10:57:33 AM »
What is this?
Is this how you nautical types genuinely dress and set the Bowline?

   YES ! This is a detail of a picture of a properly dressed and tightened bowline. The loadings of the standing end, the eye leg of the standing part and the eye leg of the bight happen to be equal.  :)
   Make an educated guess : Is it a commn bowline, or an Eskimo bowline ?
   Derek, give up... :) There is no way to distinguish if this is a detail of common bowline or a Eskimo bowline !  Why then the one is a bowline, and the other a non-bowline loop ?
This is not a knot.

xarax

  • Sr. Member
  • *****
  • Posts: 2781
Re: What defines a Bowline? - structure, characteristics, topology
« Reply #117 on: August 01, 2011, 12:18:47 PM »
   Whoever is able to untie this Gordian knot, and solve the riddle of the previous post, is kindly requested to exercise his abilities in the following, too. ;  
   Does the attached picture show a detail of a common Janus bowline, or a detail of an Eskimo Janus bowline ? Does it happen that the "first" collar is tied around the standing end, and the "second" collar is tied around the eye leg of the bight, or the opposite  ? Which is the standing end, and which is the eye leg of the standing part ?
   If we can not distinguish, due to the local symmetry of the knot s nub, the former from the later, why the one should be called a bowline, and the other simply a "loop" ? "Janus bowline" and "Janus loop", sounds like a very "Janus" situation to my ears... :)
  
« Last Edit: August 01, 2011, 12:31:00 PM by xarax »
This is not a knot.

DerekSmith

  • IGKT Member
  • Sr. Member
  • *****
  • Posts: 1530
  • Knot Botherer
    • ALbion Alliance
Re: What defines a Bowline? - structure, characteristics, topology
« Reply #118 on: August 01, 2011, 01:00:19 PM »
120 degree Eskimo

120 degree Janus Eskimo

But these are only games - now dress, set and load your knots and lets see if they behave the way Inkanyezi has demonstrated.

If we can show that the 'correctly' dressed, set and loaded bowline regularly takes up the Turn Component instead of the Half Hitch Component, then my proposed definition will need to be amended a third time.

Derek

xarax

  • Sr. Member
  • *****
  • Posts: 2781
Re: What defines a Bowline? - structure, characteristics, topology
« Reply #119 on: August 01, 2011, 02:02:40 PM »
 But these are only games - now dress, set and load your knots

  They are not games ! They are made by three tensioned/loaded legs, two of whom can be well connected and form a loop, as in a "dressed, set and loaded" common bowline or Eskimo bowline,. without any change in the detailed pictures !
  You proposed this theory, you have the burden to test it...Tie your own knots, because you will not believe me, anything I show to you ! If you wish to test your "ability to force square pegs into round holes", go on, use more carefully chosen words, like this "games..."(sic), to try to make my arguments look ridiculous...

   Why does knotting makes this thing to honest, decent people, I wonder...I , for myself, I will not continue along this slippery road. I already wrote thousands of words because I respect you, and I ,really wanted you to look on the matter more closely. Either you have not read them, or you read them but believe they are not worth reading... which is about the same thing. Eitherwise, it seems you have not understood, or wished to understand, anything at all.
   Good luck, Derek, and  enjoy knotting  !   :) I have already forgotten the whole issue.
« Last Edit: August 01, 2011, 04:39:54 PM by xarax »
This is not a knot.