Author Topic: ABoK #1031 vs Shake Hands  (Read 19659 times)

xarax

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Re: ABoK #1031 vs Shake Hands
« Reply #30 on: February 03, 2011, 12:01:05 AM »
  Two versions of Ashley s bend, in a thread about two other knots... :)
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dmacdd

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Re: Ashley's Bend jammed
« Reply #31 on: February 03, 2011, 06:54:46 AM »

   I should have waited until I had a chance to stain one of the cords,  but it was way after my bed time. (The black spots were an afterthought.) I have a pot of tea on now to stain one of the cords, and I will improve the lighting.

David, thanks, these look decent, but --yeah-- having different-colored
cords would be best.  

Here are photos of  a new instance of a jammed Ashley's bend joining cords of two colors, as promised.

The knotted 1/16" (1.6 mm) braided nylon cord, was loaded with the apparatus pictured in Jam testing several bends until the test assembly was  popping and squeaking and the test cord was extended to about 1.3 to 1.5 times its lightly loaded length. Before making the knot,  I had stained one of the two cords with tea, the better to see the structure of the knot after loading.  I made repeated unsuccessful attempts during the middle of the day to untie the knot using only my finger nails -- two or three minutes or so at a time, about ten times.

I have never been able to make a carrick bend,  Zeppelin bend, or butterfly bend even moderately difficult to untie with the same type of  cord and the same test apparatus.



« Last Edit: February 03, 2011, 07:13:22 AM by dmacdd »

Dan_Lehman

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Re: Ashley's Bend jammed
« Reply #32 on: February 03, 2011, 06:43:34 PM »
Here are photos of  a new instance of a jammed Ashley's bend joining cords of two colors, as promised.

Well, in this case --in the photos where it shows clearly--,
one can see that you have mis-tied the knot, per seeking
a non-jamming version, as did Inkanyezi.

Please follow the tying I tried to emphasize several times,
and highlight with yellow-roped *finishing path* for the
blue rope into laid rope overhand.

What we SHOULD be seeing in your jammed knots, were
they tied as above, the brown cord drawing the white tail
and vice versa, twisting them ever more securely.  Instead,
we see the opposite (images #2 & esp. #3 are clear).  Note
in #3 how the jamming mechanism --which, again, can be
exactly desired in many common cases that won't see the
extreme loading of this jam test-- is laid bare: the white collar
(this one more clearly seen) has been brought up around
the knot body, and thus can tighten around that and its own
SPart --there is only about 1/4 of its compressed width that
extends beyond the body.  This surrounding of the body is
helped by the proximate location of the tail's tuck --it is right
there beside its own SPart, whereas were the knot dressed
to resist jamming, it would be on the other side, and thus
the collar would've had much of the body to impede it.

Further to this, setting the collars tighter (less material in them)
is a stronger assurance against this surround-the-body jamming
from occurring; what is left might be pinch-of-SPart-by-bight
jamming, such as can be found in even a bowline.  (I have
now, e.g., some bowlines found in beachcombed line of
about 5/8" laid polyDAC (PP&PES) line, where one can see
taughter line on the knot side of the collar than outside of
it; with cold fingers, though, I was still able to push back
the collar over the slackened-thicker SPart and loosen one
of the bowlines --the other remains, for photo-documenting.

To this point of supposed jamming, I long ago posted images
of the properly tied (to resist) #1452 in the thread
/igkt.net/sm/index.php?topic=1446.0
of a small cord under great strain than it should probably
see, yet leaving a knot that is able to be loosened & untied
fairly easily.  Look at the upper image of the vertically aligned
white marine kernmantle cord; the upper SPart's tail is the
one point up and lying behind/under the other --a position
it has been drawn/twisted to by the heavy loading.  The
entry to this tail's tuck is plainly visible slighty lower then
knot-center, and well removed from its own SPart.
Contrast this with the image #3 above, where the similar
tail's tuck is behind the other (as viewed) and near its
SPart, and facilitating the surround-body state of the collar.

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

Is it impolite to ask why the points just made above about
distinct versions of "#1452" have been ignored?  Even in
this thread, where the issue is joined again, and I have put
a very clear, BIG-ropes image of how to tie the knot, we are
given again the naysaying "it tends to jam" assertion?
This is something everyone should be wondering about.

If one follows bad tying advice and so on, well, yes, bad
things can happen; and if one can't be bothered with fine
points about a knot then maybe it should be skipped, maybe
... Velcro will do.  Those are fair points to raise on general
recommendations; but not on this forum about particular
knots by people aspiring to knotty knowledge!

Ashley does a poor job in presenting --and maybe we can infer:
understanding-- #1452, as do other knots-books authors, it seems.
The non-jamming version was what I discovered for myself long ago
(1977-12-06), fiddling with carrick bend, butterfly knot, SmitHunter's
(my "#1"!), & shakehands --other interlocked-overhands knots
(and with such poor literature research as to find it in Ashley only six
years later!)-:  I imagined names "Dragonfly" & "Damselfly" to join
them to the fabled butterfly.  And I was happy to find the nicely
non-jamming, secure #1408, which I called "Butterfly Bend" then,
given its likeness --but with symmetry!-- to the Butterfly (of which
I'd heard about from an older rockclimbing acquaintance but took
some time to finally see).  Only rather recently (last decade?) did I
look into the effects & benefits of dressing #1452 in other ways.

Xarax's presentation more obscures than highlights the aspects
of the versions.  In having each overhand so exploded and nearly
circumscribing the other --in contrast to more pulling them resp.
left & right, exposing the parts that become collars-- he aims for
other aspects of the knots with this sort of overlay.  My big-ropes
1st image aims to highlight the part of an overhand "pretzel" where
the "spine" is opened and into which spot both the opposite
S.Part *dives* and from which its tail emeges --one focal point!
And this cannot be highlighted in those presentations (e.g., "Animated
Knots
",
by Grog) in which the knot is formed by reciprocal advances:
no, there needs to be the completed 1st overahand basis into which
one reeves by prescription just so (for whichever version of #1452,
or in other ways for other of these knots).  Neither is C.L.Day's
whiz-bang tying --much replicated-- helpful; indeed, I see now
that his completed/set knot is badly dressed!  egadz


There is yet a third dressing of #1452 to be shown, in which the
crossing point of the collars is thrust up into the knot, making
for a rather harder bend of SParts entering the collar, and a
fatter central nipping/crunching area.  In this way, it more
resembles the carrick bend.


--dl*
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xarax

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Re: Ashley's Bend jammed
« Reply #33 on: February 03, 2011, 07:36:33 PM »
Xarax's presentation[/b] more obscures than highlights the aspects
of the versions.  In having each overhand so exploded and nearly
circumscribing the other --in contrast to more pulling them resp.
left & right, exposing the parts that become collars-- he aims for
other aspects of the knots with this sort of overlay.

   The pictures posted at (1) are not pictures of the tightened knots, obviously. They are pictures of the tying methods / initial loose knots, that lead to the two distinct forms of Ashley s bend. What these pictures do show is that the topology of those two bends is different. The Ashley 1 bend can be considered as an Ashley 2 "X" bend, that is, an Ashley 2 bend where the tails are crossed before they exit the knot s nub. Is is the same thing that happens with the Zeppelin X bend in relation to the Zeppelin bend (2). The Zeppelin X bend has the (slight) advantage, over the Zeppelin bend, that its standing parts follow gentler, wider curved paths, because they are forced to wrap the thick crossing, the X, of the two tails. This is not happening in the case of the Ashley 1 bend.


1. http://igkt.net/sm/index.php?topic=2804.msg16773#msg16773
2. http://igkt.net/sm/index.php?topic=2088.msg14945#msg14945
« Last Edit: February 05, 2011, 12:39:54 PM by xarax »
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[Inkanyezi] gone

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Re: ABoK #1031 vs Shake Hands
« Reply #34 on: February 03, 2011, 08:05:40 PM »
Of course, my bad... I followed the sketch Ashley did for #1452, with the ends parallel. When the tails are crossed it's a completely different thing, and it does not jam.
« Last Edit: February 03, 2011, 08:06:19 PM by Inkanyezi »
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dmacdd

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Re: Ashley's Bend jammed
« Reply #35 on: February 04, 2011, 06:06:47 PM »
Here are photos of  a new instance of a jammed Ashley's bend joining cords of two colors, as promised.

Is it impolite to ask why the points just made above about
distinct versions of "#1452" have been ignored? 


Dan

No, but my lack of care in responding to your prior post was impolite. I apologize.

I admit to having been confused and frustrated by not understanding previous explanations of  how to reliably make a non-jamming version of 1452.

Part of my difficulty may have been that I insisted on trying to understand those explanations in terms of the method I have been using to make the bend, which may be seen here: http://davidmdelaney.com/ashley-bend/ashley-bend.html. Although I can now, as a result of this thread, reliably extend this method to make a non-jamming version, as may be seen by the attached photos, it is quite fiddly to do so, especially with cords that are not distinguished by color or pattern. 

It is troubling that the line drawing of article 1452 of ABoK seems to suggest the jamming morphology of the topology it specifies.  If we are to claim that the non-jamming morphology is also documented by 1452, we are stuck with admitting that 1452 specifies only its topology. The same may be said about the presentation of Ashley's bend that has become most common:  http://davidmdelaney.com/ashley-bend/ashley-bend.html  This in turn means that unqualified reference to 1452, or even, perhaps, to "Ashley's Bend", must be interpreted as references to the class of knots having the topology specified by 1452, which includes the jamming morphology, thus rendering valid claims that "Ashley's bend jams".

Here are two web pages that will be included in the revision of my web site. I would appreciate any comments.

http://davidmdelaney.com/jam-testing/ashley-not-jammed.html

http://davidmdelaney.com/jam-testing/ashley-jammed.html

David








roo

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Re: Ashley's Bend jammed
« Reply #36 on: February 04, 2011, 06:34:04 PM »
I would appreciate any comments.
While this whole issue is worth a footnote for academic reasons, the very fact that this subtle shift of the completed knot form has caused such confusion with knot enthusiasts should speak very, very loudly against its prospect for general use.  A good bend should not require such error-prone babying to function properly.
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Dan_Lehman

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Re: Ashley's Bend jammed
« Reply #37 on: February 04, 2011, 08:04:32 PM »
I would appreciate any comments.
While this whole issue is worth a footnote for academic reasons, the very fact that this subtle shift of the completed knot form has caused such confusion with knot enthusiasts should speak very, very loudly against its prospect for general use.  A good bend should not require such error-prone babying to function properly.

Rather, I think it speaks loudly about this enthusiasm
--about how quick some are to make pronouncements,
full of zeal but devoid of care & objectivity in analysis--,
and how poorly knots are presented and understood.

I have no trouble tying this bend, when I care to employ it,
in one version or another.  (One might employ the jamming
version for tying bungee cord, though some other knots might
be better here.  #1452 preserves its structure in this, while e.g.
the vogue RZ bend stretches out of its usual form, unless given
good setting using all ends (S.Parts + tails).)

"Rosenthal's bend", btw, was published in one Percy Blandford
book in the mis-tying 'a la SmitHunter's bend.  Did it too need
some babying to get right?  --Ps & Qs vs b&q ...  --or just some
appropriate, deserved attention!

--dl*
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roo

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Re: Ashley's Bend jammed
« Reply #38 on: February 04, 2011, 08:22:57 PM »

Rather, I think it speaks loudly about this enthusiasm
--about how quick some are to make pronouncements,
full of zeal but devoid of care & objectivity in analysis--,
...
What was careless or zealous about David's correct observation of the Ashley Bend jamming?

Quote
"Rosenthal's bend", btw, was published in one Percy Blandford
book in the mis-tying 'a la SmitHunter's bend.  Did it too need
some babying to get right?  --Ps & Qs vs b&q ...  --or just some
appropriate, deserved attention!
Publishing an erroneous diagram of the Rosendahl Bend is a separate issue from the problem of the Ashley Bend jamming depending on how the free ends happen to settle.  If the tying of the Rosendahl bend was overly difficult, this might be a point of concern, but that's not the case.  The Rosendahl Bend is actually easier to tie and check than the Ashley Bend.
« Last Edit: February 04, 2011, 08:31:13 PM by roo »
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Dan_Lehman

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Re: Ashley's Bend jammed
« Reply #39 on: February 04, 2011, 08:41:15 PM »
... I would appreciate any comments.

Just some quick-pass ones, for now.

1) The URLink to some Ashley line drawing was "404" null when
I tried; the correct image you want is NOT the large, tying one,
but the small (lower of two in line) tied one, which to my
eye indeed shows the/a jamming version, if one scrutinizes the
crossings of the tails vis-a-vis respective S.Parts and so on.
(In such issues of conflict, one can speculate which of words or
image(s) should be judged the mistake --his words here being
that it's easily untied (which could be said of the jamming version
if not loaded to the point of jamming, even).  NB:  which ought
to equally caution us that, even if no such contradiction is seen,
mistakes can be made --that is the harder caution to feel!)

2) You start off on a REALLY BAD foot in adopting CLDay's whiz-bang,
too clever by half, (mis)tying method --wish that that had never seen
daylight (and been adapted to SmitHunter's & Rosendahl's bends).
Form one overhand.  THEN aim twice at *the spot* --for passing
the working end INTO and finally back-out-from; THAT method
ensures the non-jamming form, and is nothing like "fiddly" or
all so "subtle"(roo).  The powerful rotation in unison of the opposed
S.Parts ensures the stability of this version, twisting ever tighter
(as it does for #1408, and for that particular dressing of RZ bend).

3) Of the following:
Quote
The article in which Ashley documented the bend, ABoK 1452,
does not acknowledge the issue of the knot having two distinct morphologies
with the same topology, one jamming and the other not jamming. In fact,
the line drawing he gives, which may be seen here, suggests the jamming morphology.
This suggestion of the jamming morphology in the most authoritative source means,
at best, that unqualified reference to ABoK 1452,  or to "Ashley's bend" should be
taken to be a reference to the equivalence class of a topology consisting of at least
two morphologies of which one jamming and the other is non-jamming,
which in turn means that "Ashley's bend jams" is a fair and accurate statement.


As noted above, there are more than "two"; and NB that #783 & its
reverse #781 are topological equivalents.  (I once thought that one
of these --781, I think-- could serve qua Abseil-Ropes Joiner used in
the offset loading, and seeming only risk of flyping into the secure
(and maybe a bit jammed) #1452; on some manual testing with
slightly different diameter/nature cords (approx. 7 & 8mm?), I found
that --WHOAAAAaaaaa-- one side could deform before the other,
and SPILL!!!   (Alpineer will recall my post re this.)  oops & whew!)

.:.  Be chary of speaking of topology --one can bend one's head
seriously into pain trying to fathom equivalence/difference in such terms!
(E.g., I **know** that the Fig.9 #521 =<T>= #525 =<T>= [a geometry
not shown] --happen to have the trio tied in a short play rope now--,
but it's often a royal PITA to actually manipulate the forms from one to
the other (actually, I can go between the first two, but getting the 3rd
from esp. the 2nd (IIRC) is a bridge too far, for me, yet.)

"is a fair ...stmnt" : whoa, just present the knot; you are not defending
yourself vs. libel or anything.  It would be appropriate to point out that
many knot names have such various-versions denotations --e.g.,
the very common "Fig.8" eyeknots & bends seldom indicate either the
dressing OR the loading, so cannot be understood more specifically
than this general level; there might though be differences in behavior
among what is denoted.


--dl*
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dmacdd

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Re: Ashley's Bend jammed
« Reply #40 on: February 05, 2011, 12:41:17 AM »
Dan

... I would appreciate any comments.

Just some quick-pass ones, for now.

1) The URLink to some Ashley line drawing was "404" null when
I tried;

[/quote ]

On http://davidmdelaney.com/jam-testing/ashley-not-jammed.html Fixed. Thanks.

Quote

the correct image you want is NOT the large, tying one,
but the small (lower of two in line) tied one, which to my
eye indeed shows the/a jamming version, if one scrutinizes the
crossings of the tails vis-a-vis respective S.Parts and so on.


After several minutes of trying, I cannot see that the lower tied drawing
to the left of the tying diagram in ABoK 1452
distinguishes unambiguously between the jamming and non-jamming
forms. Even if I were to become capable of seeing there what you seem to,
I would still argue

1)  that the tying diagram to the right of the tied drawings in ABoK 1452
strongly, even vividly, suggests the jamming version (I believe you agree) when it could just
as  easily have been drawn to suggest the non-jamming version.

2)  that in the absence of an equally vivid indication elsewhere as to which of the two
is to be taken as correct,  the article suggests the
the jamming rather than the non-jamming form.  As your words immediately
below suggest, Ashley's text ("easily untied" ) would be inadequate to
alert the reader to the issue, and would carry no distinguishing force unless and until
he had already engaged in research in response to observed jamming.

Quote
(In such issues of conflict, one can speculate which of words or
image(s) should be judged the mistake --his words here being
that it's easily untied (which could be said of the jamming version
if not loaded to the point of jamming, even).  NB:  which ought
to equally caution us that, even if no such contradiction is seen,
mistakes can be made --that is the harder caution to feel!)

2) You start off on a REALLY BAD foot in adopting CLDay's whiz-bang,
too clever by half, (mis)tying method



Would you supply a url for the best diagram of a tying method for non-jamming 1452 of which
you are aware?  Preferably but not necessarily a line drawing?  Preferably for a method that also tends
to preclude accidental production of 1409?

<snip>

David


TMCD

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Re: ABoK #1031 vs Shake Hands
« Reply #41 on: February 05, 2011, 01:46:19 AM »
Regarding the Ashley Bend, I've been tying it using the method shown in Des Pawson's book, basically using two P's. Both working ends go under the standing part in Pawson's example and I have very little trouble tying a great looking Ashley Bend. The above pictures are totally different than Pawson's method in his book, I think his method is easier to tie and dress.

The Shakehands Bend is hard for me to dress proper, it's a tough one to get correct IMO. I would say the Alpine Butterfly is the easiest for me to properly tie EVERY time though. Does anyone here tie the Ashley Bend using the two P's method?

TMCD

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Re: ABoK #1031 vs Shake Hands
« Reply #42 on: February 05, 2011, 03:45:16 AM »
So in order to tie the Ashley Bend correctly, one must cross the tails over each other instead of allowing them to be parallel with one another. The referenced article above states this is done by correctly placing the second p, I've done this and it must still be manipulated to cross the tails.

I really, really like the Ashley Bend, it certainly seems like the most secure bend when tied correctly. But, the Alpine Bend has been tested and it ranks right with the Ashley from what I've read and it's VERY easy to tie. No manipulation is needed and it actually is fool proof in many ways.

I'd like to hear comments about the Ashley in this regard, are you folks manipulating the tails so they cross to ensure a good bend?

Dan_Lehman

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Re: Ashley's Bend jammed
« Reply #43 on: February 05, 2011, 07:43:37 AM »
After several minutes of trying, I cannot see that the lower tied drawing
to the left of the tying diagram in ABoK 1452
distinguishes unambiguously between the jamming and non-jamming

Look at the path of the top-side collar, flowing to the tail's
exit : it clearly crosses behind the other tail, and so is then
drawn by its own S.Part (which goes around the dark side of the knot).
Whereas in non-jamming version it should be up on the viewer's side
to be drawn downwards.  --that's a key/sufficient determination.

Quote
I would still argue ...

Let's just say that Ashley's presentation is ambiguous in the large,
wrong in the small, and, thus, unhelpful at best.  And no one's
published an improvement on it to my knowledge, until we come
to this forum and put up some images and explanations, which
are now available worldwide.

Quote
Would you supply a url for the best diagram of a tying method for non-jamming 1452 of which
you are aware?  Preferably but not necessarily a line drawing?  Preferably for a method that also tends
to preclude accidental production of 1409?

No, for I don't know of one.
But why look for that, which at the least is an dependency
on something beyond your control, when you evidently
have lovely contrasting solid-color grey-brown & orange
cords (used in the Lapp Bend page --yours ?) and can make
your own, following what I've posted here, in the "writ large"
cordage, with color-coded yellow tying-completion rope.

It is really a simple enough method :
1) form the pretzel overhand in one end;
2) pull the tail away from the other part to open "the spot",
into which ...
3) the other end's spart, arcing around this upwards-facing tail
dives through the completed overhand, and then
4) forms the matching 2nd overhand (i.e., of in this 2nd end),
5) by bring the tail back up out at that spot --which necessarily
orients the tails for non-jamming behavior, going up and away
from each other (not up adjacent).

And keep in mind that the jamming, as I've said repeatedly, might
well be what is wanted --something that will stay tied in material
that won't be put to some drastic loading test!  A lot of that sort
of knotting goes on, after all.  (Though we can recall Inkanyezi's
remarks that end-2-end joints are not common in his experience,
in contrast to hitches & eye knots.)  (In the mild, desired cases of
jamming, there can be some loosening got by pulling apart the
tails, to pry the jammed collars off of the body.)

--dl*
====

dmacdd

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Re: Ashley's Bend jammed
« Reply #44 on: February 07, 2011, 01:07:24 AM »
EDIT TO AVOID THE SPREAD OF ERROR: Neither the method described here nor the photos result, as they claim, in Ashley's Bend.



It is really a simple enough method :
1) form the pretzel overhand in one end;
2) pull the tail away from the other part to open "the spot",
into which ...
3) the other end's spart, arcing around this upwards-facing tail
dives through the completed overhand, and then
4) forms the matching 2nd overhand (i.e., of in this 2nd end),
5) by bring the tail back up out at that spot --which necessarily
orients the tails for non-jamming behavior, going up and away
from each other (not up adjacent).


I find the above difficult to follow, but a little bit of reverse engineering from the bend
tied as by Day, plus a little tail twisting, as at http://davidmdelaney.com/ashley-bend/ashley-lubber-method.html, together with your text, leads me to the attached sequence of tying states.

 I believe this is what you advocate as a way to make the non-jamming version of 1452 with eyes closed?

The method shown at http://davidmdelaney.com/ashley-bend/ashley-lubber-method.html seems to require keeping eyes open to get the non-jamming version reliably.
« Last Edit: February 07, 2011, 06:25:35 PM by dmacdd »