Author Topic: ANTI Bowlines concepts  (Read 2047 times)

agent_smith

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ANTI Bowlines concepts
« on: October 05, 2018, 04:43:11 AM »
Just doing some more work on the concept of 'anti' Bowlines.
Some examples are attached (list is not exhaustive).

I believe that Dan Lehman was the first to advance the concept of an 'anti' Bowline? Verification required please...

In tying the (EBSB and Lees link ) anti Bowline structures in the attached images, I did not find those particular knots intuitive... with working end and tying maneuvers generally made in the opposite (ie anti) direction.
I can see logic in the use of the term 'anti' to describe these structures.

I have also added the #1431 Sheet bend and its 'anti' structure (aka Lapp knot/bend).

If there are strong objections to the use of the term 'anti' - I would like to see underpinning arguments against its use ahead of my next update to the Analysis of Bowlines paper...
« Last Edit: October 15, 2018, 11:02:27 PM by agent_smith »

SS369

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Re: ANTI Bowlines concepts Part 1 of 3
« Reply #1 on: October 05, 2018, 01:18:45 PM »
Rebooted attachment specs, try again.

Dan_Lehman

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Re: ANTI Bowlines concepts
« Reply #2 on: October 12, 2018, 01:59:14 AM »
I believe that Dan Lehman was the first to advance the concept of an 'anti' Bowline?
Verification required please...
Yes, it was a term that I originated, taking my cue
from "anti-cyclone" (though why go further than the
more common "anti-clockwise" I don't know!?)
--same sort of thing but in an opposite direction
was my sense of it.

Quote
I did not find it intuitive...
with working end and tying maneuvers generally
made in the opposite (ie anti) direction.
The term was tossed out as a ready *handle*
for those eye knots that are based on a central
nipping turn but where --unlike the bowline--
the returning eye leg goes through that nipping
turn from the opposite side (more to the point
than "in the opp. dir.").

A better pairing might be "front"/"back" re which side
is entered from!? AND THEN we get to cement "FRONT"
correctly!


--dl*
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DerekSmith

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Re: ANTI Bowlines concepts
« Reply #3 on: October 15, 2018, 03:20:09 PM »
The loopknot you are calling the Anti #1010 Bowline. I do not find tying this knot to be the least bit non intuitive.  Perhaps this has something to do with the fact that I do not approach making this knot with the preconception that it is a Bowline.

I don't know if other knotters have found the same thing, but for me, 'where you start' (and this includes mental preconceptions) has a huge influence on the ease of making a knot and of understanding its form and function.

So, to make this knot, I start by making a loose slipped OH (you can make the OH either LH or RH), with the WE being used to form the slip loop.  So far - easy peasy.

The next step is to take the WE and pass it into the slipped loop (either front to back or back to front).

Of course, if you want to make this loopknot around an object - a tree, or a bar - then pass the WE around that object before passing it into the slipped loop.

Now, if we belonged to the knotting fraternity who draw a knot how we have formed it, we might be tempted to call this the 'Slipped OH Eyeknot', but then, perhaps not, because this is still patently nothing like a usable knot - we need to load it to dress it.

To dress the knot, simply take the SP and the slipped leg from the OH and pull.  The slipped loop will pull through and fold the WE into the bight component and the OH will wrap around the bight to form the hitch component (apologies to Xarax as he is not here to explode at my use of the term).

And there you have it - depending on which of the four combinations you used - you have the famous (or should that be infamous) SHEETBEND LOOPKNOT.  It is not an anti this that or anything - it is a Sheetbend configured as a loopknot.

Starting in this place, it is not non intuitive, it takes ca 3-4 seconds to make it, it is ring load stable and from my limited testing so far, all four variants appear closely equivalent in performance.

But then, what is in a name, but perhaps perspective?

Derek

NB - if you flip this over and make the OH the WP and the slip loop the SP, then you form the variants of #1010 Bowline - happy knotting.

agent_smith

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Re: ANTI Bowlines concepts
« Reply #4 on: October 15, 2018, 11:26:39 PM »
The eye knot I refer to as an 'anti Bowline' is not the structure I found non intuitive.
I found the anti EBSB and anti Lees link Bowlines non intuitive.
In any case, who cares what I found less intuitive?
Its all beside the point and entirely nebulous.

The point of the original post was to explore the concept of the term 'anti' - and not explore one persons findings of intuitiveness.

For me, the key component (or element) that underpins all Bowlines is the nipping loop (which takes the form of a helix in the primary Bowlines).
With the 'anti' Bowlines, tying maneuvers (once the nipping loop has been formed) are generally made in the opposite (or anti) direction.

Whether a person prefers to conceptualise the term 'anti' as referring to 'opposite direction' or as 'opposite side' is a matter of perspective.
However, some may not accept the concept of 'anti' at all - preferring to reject it.

If one accepts the notional view that at the heart of all Bowlines is a nipping loop (which takes the form of a helix in the primary Bowlines) - it should be a relatively small step to understand the core structure. On the other hand, it may be a giant leap for some - who (for one reason or the other) may not see, or understand the significance of the nipping loop within all Bowlines.
« Last Edit: October 15, 2018, 11:52:33 PM by agent_smith »

Dan_Lehman

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Re: ANTI Bowlines concepts
« Reply #5 on: October 15, 2018, 11:49:38 PM »
I don't know if other knotters have found the same thing, but for me,
'where you start' (and this includes mental preconceptions) has a huge influence
on the ease of making a knot and of understanding its form and function.
Indeed, that can be so, in those cases where the tying
steps can be seen to add in components that do this
& that as needed for a successful result.  OTOH, there
are some tying methods that rather disguise what wil
result from some final whiz-bang maneuvre --and VOICI !!

Quote
... you have the famous (or should that be infamous) SHEETBEND LOOPKNOT.
It is not an anti this that or anything - it is a Sheetbend configured as a loopknot.
I don't see it as sheet-bend related so much at all,
for the SPart is putting 100% force on a part that
corresponds to a tail (0% force) in the end-2-end knot!
Though we did recently encounter a referenced site
in which this mis-moniker was used to describe what
we'd call the Eskimo bowline.

As for "not anti this or that", please heed my remarks about
the origin of "anti-bowline" :: it was simply to put a handle
on those nipping-loop-based eye knots where the returning
eye leg enters from the opposite side, that's all.  --so, like
the cyclone that rotates in the opposite way ... .
"Front(-side)/Back(-side)" might be the better terms to use,
or something like "discordant/concordant" adjectives used
by CLDay (et al.?) for versions of the fisherman's knot.

Quote
... it is ring load stable and from my limited testing so far,
 all four variants appear closely equivalent in performance.
NB that testing where it proves intended-loading UNstable,
capsizing!

Quote
NB - if you flip this over and make the OH the WP and the slip loop the SP,
 then you form the variants of #1010 Bowline - happy knotting.
Ha, I almost inevitably end up with Ashley's "Lefthanded" one,
I don't know why (I tend to do it this way).

 ;D

Dan_Lehman

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Re: ANTI Bowlines concepts
« Reply #6 on: October 16, 2018, 12:09:49 AM »
For me, the key component (or element) that underpins all Bowlines is the nipping loop
(which takes the form of a helix in the primary Bowlines).
As opposed to what?

As I know of a series of eye knots that make use of
what is IMO a much fuller realization of the term "helix",
I really groan each time I see you likening the LOOP
to be a helix.  (As I've noted, it of course IS, unless
one endeavors to avoid that by using penetratable
cordage such as a loose hollow braid ... ; but it is
that only at, ideally at, the most minimal helix angle.
And, yes, one can watch this angle grow with load
on e.g. #1010 even.)
Still, conceptually, I think we should manitain some
measure of distinction between helical structures
and "loops"; the former cannot give quite the same
*constriction* of enclosed parts, as they lack the
on-other-side-of-this-point resistance that a ring's
opposite-sides points have (9:00 & 3:00 pinching
between them, as for other point-pairs around the
loop; but not so much when substantial helix geometry
obtains).

NB : there are bowlines (IMO) where there is arguably
no through-the-loop returning-eye-leg penetration,
making them neutrals in this delineation.  (Well, yes,
ultimately if one follows the RtEyLeg's part back into
the knot it ultimately goes through the turNip, but
at quite some remove from being an eye leg, at least.)


--dl*
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Dan_Lehman

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Re: ANTI Bowlines concepts
« Reply #7 on: October 18, 2018, 10:19:04 PM »
For me, the key component (or element) that underpins all Bowlines is the nipping loop
(which takes the form of a helix in the primary Bowlines).
Still, conceptually, I think we should manitain some
measure of distinction between helical structures
and "loops"; the former cannot give quite the same
*constriction* of enclosed parts, as they lack the
on-other-side-of-this-point resistance that a ring's
opposite-sides points have (9:00 & 3:00 pinching
between them, as for other point-pairs around the
loop; but not so much when substantial helix geometry
obtains).
Another thing to consider is :
what is the helix angle of a bowline's nipping loop?
In a sense, it would be *negative* relative to the
disposition of the line as it goes away (whereas
that of what I call "anti-bowlines" tends to be
so helical that good measures are needed to
contain its angle so to be an effective *loop*
in nipping!).  In other words, rather than going
in a true/positive helical wrapping when the
SPart forms the nipping loop, it wraps *back*
upon itself!?  And in capsizing --which these
knots can do ...--, the loop must be turned
upside-down/backwards and they does indeed
go helical!


--dl*
====

DerekSmith

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Re: ANTI Bowlines concepts
« Reply #8 on: October 19, 2018, 07:02:16 AM »

Quote
... you have the famous (or should that be infamous) SHEETBEND LOOPKNOT.
It is not an anti this that or anything - it is a Sheetbend configured as a loopknot.
I don't see it as sheet-bend related so much at all,
for the SPart is putting 100% force on a part that
corresponds to a tail (0% force) in the end-2-end knot!
Though we did recently encounter a referenced site
in which this mis-moniker was used to describe what
we'd call the Eskimo bowline.


@Dan

Yes, in its usual (i.e. book presentation) form, the Sheetbend is acknowledged as an 'end-2-end' knot.  But is this the only conformance that we will accept this structure as being the Sheetbend?

For example, will you permit the name if I now bend two cords, but instead of e-2-e, I make an end-2-midline bend?  The knot still handles 100% of the loading, it simply has a 'very' long WE.

If e-2-ml is acceptable, then, what is I now apply a very small tangential loading to that 'long WE'?

I am sure you can see where I am going with this...  If it is still a Sheetbend when I apply a small tangential load, what if I continue to increase that load until all three lines are equally loaded (a condition the SB is well suited to handle) - is this 'midline bend' still the Sheetbend?

And if it is, then at what loading ratio must we cease calling it a Sheetbend?  Because, as I am sure you have already seen, we are now only a tug away from the operational knot which forms the Eskimo loopknot.

[Of course, three way loading is only the beginning of the extrapolation - what about four way loading as utilised in the billions of applications of this knot when making nets?]

We start to have to face the reality that a Loopknot is formed when a cord is bent back onto itself.

Derek

Dan_Lehman

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Re: ANTI Bowlines concepts
« Reply #9 on: October 19, 2018, 09:23:35 PM »
Yes, in its usual (i.e. book presentation) form, the Sheetbend is acknowledged as an 'end-2-end' knot.
But is this the only conformance that we will accept this structure as being the Sheetbend?
Rather, it is so defined.

Quote
For example, will you permit the name if I now bend two cords,
but instead of e-2-e, I make an end-2-midline bend?
The knot still handles 100% of the loading, it simply has a 'very' long WE.
You make a mistake, well, presumption here that comes
out later :: simply, there are two ways to, um, *sheetbend*
this added line --i.e., to U-part it into a turn of the other
line, or to turn it into the other line's bight!  (Just as we
should remark that to the extent that the bowline is
the eye-knot correspondent to the sheet bend there
remains a 2nd corresondent with U & loop constructs
in the opposite pieces of knotting!

Now, your millimeter-by-microgram moving from tail
to something w/tension is, yes, understood as pressing
the question about a black-&-white definition boundary.
Let me remind you that you're writing to one who has
ventured a cookie-cutter-circle view of a knotted *tangle*
where what goes on outside of there is immaterial to the
definitions of knot classes and so the "eye knot" might
not have an eye !  --just in your way of joining a 2nd
line into the first and loading it ... qua *eye knot* : one
end A (of piece A-B) opposing end B & end 1 (of piece 1-2),
end 2 being unloaded.

For an in-practice actual eye, the normal case is pretty
much equal tension on the two legs; some movement
of a boat e.g. with friction on a pile can alter this.
Now, in you example where there is no eye, there is
not sure/natural balance of tensions,
and the definitional challenge rises.

Rather than thinking here "What is right?" we should
ease into "What (definition/nomenclature) will best serve us?!

And I don't know the answer.
We might define canonical classes & their loading profiles
and do much work on these;
and also acknowledge --esp. if there are good, actual-factual
cases to address, not mere What ifs from an Ivory Tower--
the rough edges & compromised states in between.
Because the pure *eye knot* that you have tied in with
could somehow snag and become an e-2-e knot, like
it or not!  --not while you're defining ..., but FALLING !!

But for now, no, a "sheet bend" is a known and well-enough
articulated e-2-e knot; taking that structure into other
waters will be to whatever extent going outside that
definition, and I don't think that the name should follow
on this chase.

--dl*
====
« Last Edit: October 20, 2018, 04:27:50 PM by Dan_Lehman »

DerekSmith

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Re: ANTI Bowlines concepts
« Reply #10 on: October 21, 2018, 01:15:43 PM »

But for now, no, a "sheet bend" is a known and well-enough
articulated e-2-e knot; taking that structure into other
waters will be to whatever extent going outside that
definition, and I don't think that the name should follow
on this chase.

--dl*
====

Yes, of course, your conclusion is correct and I accept it.

However, I believe that we face the dichotomy of the conclusion being simultaneously right and wrong for exactly the same reason.

The Ashley Book of Knots was compiled and published a lifetime ago, yet in that short span of time, the changes we have experienced are staggering.  One of the most significant being the means by which you and I are communicating this reply.  The age that ABoK references though, communicated predominantly face to face and by 'Show and Tell'.  Trade knowledge and skill was transferred through apprenticeship with tools and methods being identified by names often specific to that trade.  Knots were no exception with a knot name relating to a Trade, its use, the cordage and even the method of tying it.

In this respect, the above conclusion is totally correct - the name Sheetbend is specific and the name is not applicable to situations where the same topology is used in any other configuration.  If anything, we are already misusing / overloading the name by ignoring some of the specifics the name defines, but despite this it remains a valuable mnemonic for teaching many thousands of Scouts and Guides the form, method and use of this valuable knot.  But that is all we taught them, we stayed within the strictures of history and only teach form, method and usage.

This then is where I feel that simply blindly following history and teaching Name - form - method and usage, is wrong.  In the name of learning and progress, should we not be considering why this knot is so widely utilised, how it works and if / why it fails?  Should we not be promoting the essentials of this valuable and fundamental knot?  Of course, to do this we would need a root name for this knot core - what would be appropriate and memorable?  From this root, then all the 'Sheetbend' based knots could be referenced (including the now infamous Sheetbend Loop).

At some point change and clarity must come to our morass of historical namings, and that change must start somewhere.  This forum is not ideal, but it could make a useful debating platform.

Derek

Dan_Lehman

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Re: ANTI Bowlines concepts
« Reply #11 on: October 23, 2018, 01:48:40 AM »
The Ashley Book of Knots was compiled and published a lifetime ago, ...
Derek, I do hope that you take a look at the marvelous
HNG Bushby manuscript, done ca. 1902-7 (I'll guess, though
latest date --an unfinished work-- is 1926 (RIP)), well prior
Ashley.  Goggle "Mariners' Museum catalogue" and then
Search the Catalog link & simply "Bushby" should bring
a page of clickable icons (not assoc'd text/titles!) to get
into the historical document!

Quote
  Knots were no exception with a knot name relating to a Trade,
its use, the cordage and even the method of tying it.
But one can wonder to what extent the literature of
and about that time/activity is accurate; there are certainly
painfully INaccurate  & nonsense items  (I think the bulk of
Hensel & Gretel is that, as far as practical knotting goes
--truly appalling, and in 4th ed. prominently published ... !).

Quote
This then is where I feel that simply blindly following history
Esp. the "blindly" comes to mine here re my above
lament; what is often followed is just what was previously
written --sometimes a history of literature and not knots.

Quote
Should we not be promoting the essentials of this valuable and fundamental knot?  Of course, to do this we would need a root name for this knot core - what would be appropriate and memorable?  From this root, then all the 'Sheetbend' based knots could be referenced (including the now infamous Sheetbend Loop).
And would you like to write the chapter about the
"hitch component" ?!  ;D   ;D   ;)

IMO, yes, you point to a way to go :: to teach *knotting*
to a greater degree, with efforts to show how structures
go into this or that application & materials & needs with
this or that adaptive feature (or maybe an initial attempt
to adopt but then failure).

But partly to this, we should bemoan the inactivity on
Practical Knots (I wanted "Knotting") debut thread,
Knots in the Wild --the feed of observations into our
database.

--dl*
====

DerekSmith

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Re: ANTI Bowlines concepts
« Reply #12 on: October 23, 2018, 07:17:03 PM »
Thank you Dan for that Bushby reference.  I have downloaded all seven volumes together with the the index of knots (they need to be referenced in our IGKT online library).

I was amazed when I opened Volume 1, and there on the first page, noted in the margin at the bottom of the page was a small table of 'Crossings' and 'No. of Knots' !!!  Then on pp3, the title 'Modes of considering knots', with almost a throwaway comment that this is a FOUR dimensional problem, with the clear inference that usage and dynamic functionality are part of this consideration.  pp62 image of the Alpine Butterfly but called the 'Dalliance Knot', and a list of common names for the Sheetbend that included every conceivable combination of loop,eye,bend, hitch, beckett, bowline, Weaver, and of course, sheetbend, that you can imagine - and we think we have problems...

But the fact that back in 1902 he is listing seven perspectives that need to be considered in classification, and not to forget that throway 'fourth dimensional consideration', then in truth, it feels like we are going backwards as time is passing.  Perhaps the film 'Idiocracy' is the truth in the jest.

I was starting to feel a bit guilty for sidetracking Mark's original thread, but now I am convinced we need to progress the rationalisation of our knot universe.  Bushby detailed in his third category of classification - '3. Analytical : eg as to the elements into which they can be split up.  Thus a sheetbend  = a hitch + a loop' - that was 1902, how far have we developed this method since then?  Hardly at all, and that is to our shame.

So perhaps now is the time to start clearing our decks of nonsense, and this thread is as good a place as any.

Q.  When is a Sheetbend not a Sheetbend?

A.  When it is an Antisheetbend - because in the 'anti' configuration the components have changed their configuration such that the knot is no longer a Sheetbend of any form because in this new loading configuration, the hitherto 'nipping helix' has been converted into a Carrick Component.  I do not know what this new knot should be called, but it is not a Sheetbend anything.

Derek

NB  I have long felt that 'Knots in the Wild' is a critical part of our usage and understanding of knots (it should have its own child board rather than just a single thread).  Bushby's clear perception understood the need for including this aspect of knots in his declaration that we should be considering all four dimensions in our assessments.  The dynamics of a knot in use throws our somewhat blinkered approach of using stylised static imagery to depict a knot into question.  Rather we should be considering the 'what if' questions relating to spurious sources of force.  Which of course takes us straight back to the Sheetbed Loopknot concept.

What have you done Dan?


Dan_Lehman

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Re: ANTI Bowlines concepts
« Reply #13 on: October 23, 2018, 10:38:46 PM »
Thank you Dan for that Bushby reference.  I have downloaded all seven volumes together with the the index of knots (they need to be referenced in our IGKT online library).

I was amazed when I opened Volume 1,
and there on the first page,

 noted in the margin at the bottom of the page was a small table of 'Crossings' and 'No. of Knots' !!!
Very quickly, I must scoot!
1) There is no "pg.1" of Vol.1 --it was MISSED
(and would be that page facing the inside cover,
which is how the on-line file begins; next on-line
is pg.2 (TWO), alas).  (Note "Authorities continued"
on cover, which refers to his notes on missing pg.1
--a copy of which I have, from on-site visit.)

[edit :: 2 B clear, the actual manuscript has a pg.1
in Vol.1, but the on-line files do not.  This missed page
contains various info including the start of his (List of)
Authorities. ]

2) Otherwise, your "Bottom of page" comes rather
in the center of the physical inside-cover page.

To the Swede who discovered the existence of this
manuscript, he could only exclaim "IT IS AMAZING!!!"
when he finally got to see it in a printed-for-him PDF,
thankfully prior is recent passing.


--dl*
====
« Last Edit: October 24, 2018, 11:26:44 PM by Dan_Lehman »

DerekSmith

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Re: ANTI Bowlines concepts
« Reply #14 on: October 24, 2018, 12:52:58 AM »
Hi Dan,

I didn't say pg.1  -  I said the first page of volume 1

And I have to agree with the Swede - it really is amazing...

Thank you again for pointing me in its direction.

Derek