Author Topic: Eskimo Janus bowlines  (Read 8685 times)

X1

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Eskimo Janus bowlines
« on: March 29, 2013, 03:42:31 PM »
   There are four variations of the "Eskimo" bowline, and two variations of the common bowline ( the "right hand" and the "left hand"). On top of that, if the working end has already gone through the nipping loop two times, there are many ways it can go through it for the third and last time, as a tail. So, there are many different variations of an "Eskimo" Janus bowline - which is nothing more that a common Janus bowline, where the first collar turns around the eye leg, and the second around the standing end - on purpose, or by mistake !
   I have seen that the general crossing knot-based eyeknots, in general, and the "Eskimo" (-)bowlines, in particular (*), are out of knot tyers fashion - for no good reason. These post-eye-tiable eyeknots are very stable and secure knots, and we can not really say that they are not as "simple" as the common bowlines. Moreover, I believe that, regarding the compound Janus bowlines, the disadvantages of the parent "Eskimo" bowlines disappear, and we are left with the advantages : the more rigid, self-stabilizing nipping structure, and the L-shaped segment of the returning eye leg, which serves as a "step" for the loop below it, as well as a "handle" for the standing part above it.
   Have a look at the "Eskimo" Janus bowline shown at the first two attached pictures, and compare it to the similar knot shown at (1) and at the third and fourth attached pictures.   

* The "Eskimo" bowlines differ from most crossing knot-based eyeknots, in that their nipping structure has one only crossing point - in the ante-eye portion of the eyeknot, the standing part cross itself only one time.
1. http://igkt.net/sm/index.php?topic=4125.msg24820#msg24820
« Last Edit: March 29, 2013, 03:45:24 PM by X1 »

X1

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Re: Eskimo Janus bowlines
« Reply #1 on: March 29, 2013, 03:55:11 PM »
   "Pencil Sketch" images of the same knots.
« Last Edit: March 29, 2013, 04:20:05 PM by X1 »

Dan_Lehman

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Re: Eskimo Janus bowlines
« Reply #2 on: April 01, 2013, 05:35:40 AM »
   There are four variations of the "Eskimo" bowline, and two variations of the common bowline
( the "right hand" and the "left hand").
And then we might call out "versions" in which the
dressing comes into play (with the tail's position in
anticipation of the draw of the SPart).  (And noting
that Ashley's #1033 can also take an "Eskimo"
variation --which in a way can be seen as also being
the "left-handed" path : i.e., the tail's path is reversed.)

Quote
On top of that, if the working end has already gone through the nipping loop two times,
there are many ways it can go through it for the third and last time, as a tail.
I like the first, but maybe prefer taking the tail out
through the *center* of the turNip, which shows
as an inviting hole-target; it might make for the most
rounded curvature of the SPart.
(And my idea of "front/back" is opposite the common one,
as I've argued several times elsewhere!   But in these knots
with added collars, one has tuckings from both sides, so my
point is lost or diminished, as far as visibility is concerned.  ;) )


Quote
I have seen that the general crossing knot-based eyeknots,
in general, and the "Eskimo" (-)bowlines, in particular (*),

Whoa, I differentiate between these, though it's a matter
of degree (but there is a significant & obvious difference
between the hard-set knot and what I aim for, where
I want the loop manifest, not a crossing knot) !
(You have a footnote to this effect, but I would simply
not so categorize them at all; we simply have to recognize
that the boundary is one of degree --or one that can come
to a fuzziness by degree, from clearer, distinct forms.)

I do have a feeling that I prefer the Eskimo-loaded structure
to the bowline-loaded one as you show and I revise for
the first knot.  I.e., one can connect the tail-side of the eye
to end as shown and have a *"bowline"* not an *"anti-bowline"*
but I think I like the latter, better (and am not sure why).


--dl*
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X1

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Re: Eskimo Janus bowlines
« Reply #3 on: April 01, 2013, 05:26:15 PM »
maybe prefer taking the tail out through the *center* of the turNip, which shows as an inviting hole-target;

  Nooo ! This is an inviting trap ! Beware of its seductive siren song ! I have sensed, seen, felt and measured, that the tail can not be nipped efficiently there - because the other segments that would encircle it would also play the role of a weaved cocoon, of a protective knitted shield. They will absorb a great portion of, and they will obstruct the constricting power of the nipping loop, to reach and bite it hard. ( I am always talking about kermantle, stiff climbing ropes, of course.) I always deliberately drive the tail away from this black hole - even if this would have been the unstrained, "natural" path a less curved working end would have followed, or if it, by the very bulk of the tail placed there, would had allowed a less curved standing part.
  So, to secure the tail in the more efficient way, we must find a place within the nipping loop where it will be bitten hard by the standing part s and/or the returning eye leg s first curve(s) - AND where it will not pass through those two dangerous spots : This central black hole ( when there will be other segments that will encircle and "protect" it ), and the "soft spot" near the nipping loop s crossing point ( where it will be nipped by the two converging legs of the nipping loop only, and not by its rim ).
  If this black hole was not so dangerous, it would have been the ideal resting place for the tail in the retucked Myrtle loop... By the same token, the re-tucked ( through this "hole-trap, NOT hole-target" ) Myrtle loop, tied on soft, not-stiff ropes, is a very secure, well-balanced, compact and nice post-eye-tiable loop !

   I differentiate between these, though it's a matter of degree (but there is a significant & obvious difference between the hard-set knot and what I aim for, where I want the loop manifest, not a crossing knot) !
 

  It is significant, and it may be obvious, but that does not settle the issue ! I have tried to find an objective quantitative way to define the differences, and I have not found anything else /better than this "number of crossing points of the standing part within the nipping structure" measure. It is true that there are "obviously" crossing knot-based loops that have only one crossing point, because the standing part does not touch the nipping loop a second time - they may be separated by another segment that is squeezed in between them so they can not touch each other, or they may remain just a few millimetres apart... However, the majority the of the crossing-knot-based loops I know can be distinguished from the "Eskimo" (-)bowlines this way - so I feel that this measure is not worthless.
  I have also thought of another measure, based upon the relative positions of the crossing point and the centre of the nipping loop in a loaded eyeknot : iff the crossing point is located well "higher" than the centre of the nipping loop, we have a crossing knot-based loop,- if not, an "Eskimo" (-) bowline. However, this "higher" can not be quantified in the same unambiguous / objective way the "number of crossing points" can, so it conveys the sense that the difference is "a matter of degree", much more than it should !
« Last Edit: April 01, 2013, 05:45:24 PM by X1 »

Dan_Lehman

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Re: Eskimo Janus bowlines
« Reply #4 on: April 02, 2013, 06:13:04 AM »
maybe prefer taking the tail out through the *center* of the turNip, which shows as an inviting hole-target;

  Nooo ! This is an inviting trap ! Beware of its seductive siren song ! I have sensed, seen, felt and measured, that the tail can not be nipped efficiently there - because the other segments that would encircle it would also play the role of a weaved cocoon, of a protective knitted shield. They will absorb a great portion of, and they will obstruct the constricting power of the nipping loop, to reach and bite it hard.
...
No matter, the tail is nipped sufficiently here --i.e.,
it doesn't slip--, and is in any case already a secondary
securing, coming atop an already secured Eskimo Bowline.


--dl*
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X1

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Re: Eskimo Janus bowlines
« Reply #5 on: April 02, 2013, 07:52:06 AM »
the tail is nipped sufficiently here --i.e.,it doesn't slip--, and is in any case already a secondary securing, coming atop an already secured Eskimo Bowline.

   True, but that is not sufficient to me... I always want this last line of defence ( against slippage ) be the strongest one, if possible - otherwise, when the first one will be crushed or outflanked, this will probably be swept away, too. The last point the tail is nipped is like the inner, high fortress, and I think that it should be higher than the outer fortification walls... ( See the attached picture ). I have seen the same thing in bends, too - when the tail is nipped at two points, and the strongest one is the first, the chances are that any slack between the first and the second left during the knot was set up, will remain, so the knot will not be as compact as it would have been if the order those two lines of defence against slippage were arranged had been the opposite.

X1

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Re: Eskimo Janus bowlines
« Reply #6 on: April 03, 2013, 01:58:00 PM »
... there are "obviously" crossing knot-based loops that have only one crossing point, because the standing part does not touch the nipping loop a second time... they may remain just a few millimetres apart

  Two examples are shown at the attached pictures.
  Also, See :
  http://igkt.net/sm/index.php?topic=3467.msg24483#msg24483

Dan_Lehman

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Re: Eskimo Janus bowlines
« Reply #7 on: April 04, 2013, 07:04:25 PM »
the tail is nipped sufficiently here --i.e.,it doesn't slip--,
and is in any case already a secondary securing,
coming atop an already secured Eskimo Bowline.
   True, but that is not sufficient to me...
I always want this last line of defence ( against slippage ) be the strongest one,
if possible - otherwise, when the first one will be crushed or outflanked,
this will probably be swept away, too.

While I have sought this reasoned structure
in devising my set of compound tie-in knots
 --
where the outer / away-from-eye knot
   (which will take fall forces yet remain easy to untie)
  can fall apart to leave a should-be-always-secure base knot
   (which in my surest structure is a noose-hitch,
    where the nipping is independent of the hitched-to object (rope)
    for security, and is secure in an *open* setting)--,
I don't see it as a good design principle for a single nub.

Consider the case of weakening deflections/bends :
you want the strongest bend (likely, least curved)
to come first, to diminish the force that can be delivered
to the later-reached, sharp ones.  I think that a similar
reasoning works for security --later places have less forces
to deal with, if the earlier nips are stronger : and thus,
all nips work sort of *simultaneously* for effect, and
the nub is better preserved in integrity,
rather than possibly suffering the deformity of weakened
early nips that rely on some surer, last-g(r)asp holding.

One also needs to take care in guessing the circumstances
that might require the last security.  In my compound-nub
structures, it would be foolish to simply undo the outlying
bowline and then consider what's left --in some fairly
well-set state-- in terms of its isolated security : rather,
one has to figure that the only way this last-chance knot
could come to be depended upon would be that the entire
structure was loosened enough to enable the untying
of the bowline --and that can quite change the picture!
(Largely, IMO, it changes it to dropping the goal of having
such a two-step structure; rather, see the complexity as
providing surer up-front security against any loosening!)


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X1

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Re: Eskimo Janus bowlines
« Reply #8 on: April 04, 2013, 11:22:40 PM »
... you want the strongest bend (likely, least curved) to come first, to diminish the force that can be delivered to the later-reached, sharp ones.  I think that a similar
reasoning works for security

   I read the same line, in the exact opposite sense !  :) You want the least curved bend ( the one that will diminish the force less than if it was sharper ) to come first, so to diminish the force that will be delivered to the later-reached, sharper one ( the one that will diminish the force more than if it was less curved). So, you want a first force-absorbing point, a first line of defence, that will be weaker than the second force-absorbing point, the second/last line of defence, that will be stronger. Welcome to the International Guilt of Castle builders !  :)

  I think that a similar reasoning works for security --later places have less forces to deal with, if the earlier nips are stronger : and thus, all nips work sort of *simultaneously* for effect, and the nub is better preserved in integrity,

  Here we go again : Later places have less force to deal with, simply because there exist earlier places, period. The earlier places can be weaker or stronger than the later places - the previous argument is valid in either case, without specifying the order of the relative strength between the two places / lines of defence !
  Now, think in how many situations/attacks do we wish this simultaneous defence : If the first line is weaker than the later, the chances are that both lines will be collaborating most of the time - simply because the first will need the second more times than it would had needed it had it been stronger. So, if the first line of defence against slippage is weaker than the second, most of the time we will have both lines working in tandem, without the segment of the rope between them be slack - i.e., most of the time we will have a compact knot s nub. On the contrary, if the first line of defence is stronger than the second, it will, alone, hold more times than if it would have hold had it been weaker, without any help from the second line, or from anybody else ! Soldiers on the second line will have a good time just watching what is happening, that is true - although they will not be able to enjoy the view, and see their enemies been exterminated, because their inner fortress will be lower than the outer fortification walls... If I were a general (brrr...), I would not feel so happy to sit on the top of a low tower, without been able to see what is happening outside the higher outer fortification wars, AND with the sight of all those lazy soldiers around me, that, most of the times, will not fight, and will be not utilized ( = will not die).
   If the fist line of defence is weaker than the second, regarding the same distribution of weak and strong external loadings, both lines will be used simultaneously more times than if it had been weaker... I have seen this in practice. The ropes I use are 9 - 12,5 mm climbing ropes, and the loadings to which I am able to test them are weak, relatively to their size. So, many times I have seen an end-to-end knot (bend) or an eyeknot ( loop) that has not been optimally designed according to this idea I had tried to explain, where the "first" places the pulled standing end or eye leg are bent or nipped are the only ones that are really needed and loaded - and the remaining places remain remaining a heavy enough load... where their collaboration will, at last, be needed and used. That means that, most of the time, such a knot would need a careful set up, and a strong pull of the tail, to become compact and reach its "final" form - the weak loading by itself will only leave the "later"/"second" part of the rope unused, and the segment(s) between this part and the "earlier" / "first" part loose... 

rather than possibly suffering the deformity of weakened early nips that rely on some surer, last-g(r)asp holding.

   Better sooner than later ! At the "final" form, which is the form with which the knot will confront the heavy loading, this deformity would have occurred already. So, I prefer a knot that, most of the times, even under weak loadings, will have the same form as its final form - because the earlier and the later lines of defence against slippage will be collaborating simultaneously.

  In my compound-nub structures, it would be foolish to simply undo the outlying bowline and then consider what's left --in some fairly well-set state-- in terms of its isolated security

  That means your compound-nub structures are not two-stages structures, where the second line of defence can hold, even if the first one has been crushed ... However, the "Mirrored bowline", although it is a compound -nub structure ( is nt it that so ?), does not belong to this category, I believe...
  On the contrary, when I seek a "safe bowline", I search for a bowline that will hold, even if its collar is loose, or it is cut off, or it is untucked altogether ! That is why I search for self-stabilizing nipping structures, that will retain their integrity even without the first stage/part of the collar structure - and/or with as little amount of help from the whole collar structure as possible.
  Read (1), where I had to decide which bowline ( out of two "similar"(?) and beautiful knots ) is to be preferred, and I did it by just applying this line of thinking - and nothing else !

   1. http://igkt.net/sm/index.php?topic=4125.msg27085#msg27085
« Last Edit: April 04, 2013, 11:28:17 PM by X1 »

X1

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Re: Eskimo Janus bowlines
« Reply #9 on: April 06, 2013, 11:30:33 PM »
   I should nt let this opportunity slip, without mentioning something about the number of the possible Eskimo Janus bowlines.
   Let us call the segment that connects the two collars of any Janus bowline, the collar around the standing end and the collar around the eye leg of the standing part, the "bridge" of the knot. Also, let us not distinguish, for the moment, the continuation of the eye leg, which enters into the nipping loop,  from the tail, which exits from it - let us see them as the two limbs of the "collar structure", that is interweaved on the standing part s nipping loop, the "nipping structure".
   We can sort the possible Janus bowlines in two broad categories : the knots where the two eye legs penetrate the nipping loop going through the same side of the bridge ( the "symmetric cases ), and the rest - where each eye leg passes from a different side of the bridge ( the "asymmetric" cases ). As the loading of the knot is, obviously, not symmetric, I suspect that the optimum, structurally, knots would be the "asymmetric" ones... but they would also be the most difficult to remember. So I really do not know if there is any point to tie the "asymmetric" knots, instead of the "symmetric".
    Regarding the "symmetric" cases, we can have the following possibilities :
   1. The spatial order of the three following elements can be as :
   a. crossing point of the nipping loop - crossing point of the two limbs of the collar structure - bridge, or
   b. crossing point of the nipping loop - bridge - crossing point of the two limbs of the collar structure.
   2. The two limbs of the collar structure can be in an "over-under" or in an "under-over" position - the one "over" or "under" the other.
   3. The continuations of the bridge can collar the two limbs of the nipping loop, the standing end and the eye leg of the standing part, following a clock-wise or a counter-clock wise path. I call, for no specific reason, "clockwise" the path where this bridge is not very "twisted", and "counter-clockwise" the other, more curvilinear path.
   4. The Janus bowline can be a "common" one, where the continuation of the returning eye leg collars first the standing part, or an "Eskimo" one, where it first collars the eye leg of the standing part.
    So, we see that we can have 2 x 2 x 2 = 8 "common" "symmetric" Janus bowlines, and 8 "Eskimo" "symmetric" Janus bowlines. Not bad, for starters !   :)
    See the attached pictures.  Let us suppose that the standing part ( red line) goes from left to right ( at the left side of the picture is the standing end, and at the right side the eye leg of the standing part). Then, the limb of the collar structure (white line) which lies at the left side of the frame is the tail, if we have a "common" Janus bowline - or the returning eye leg, if we have an "Eskimo" Janus bowline. By the same token, the limb of the collar structure (white line) which lies at the right side of the frame is the returning eye leg, in the case of the "common" Janus bowline - or the tail, in the case of the "Eskimo: Janus bowline.
    I am spending all those bits and bytes, and the interested readers time, to point out one thing : It is better if the returning eye leg squeezes the tail, i.e.. their position is such that the returning eye leg, in the loaded knot, goes "over" the tail. This provides an additional lock, another degree of security, another, strong line of defence against slippage. So, from those 8 "common" plus 8 "Eskimo" Janus Bowlines, we should better chose and tie the 4 plus 4.
   I am thinking that the "Eskimo" Janus bowlines are more secure than their "common" twins, because the returning eye leg has this L-shaped segment, as it bents before it reaches the collar - and this deflexion might be beneficial to the absorption and distribution of forces coming from the bight. As the first collar, around the eye leg of the standing part, contributes in the overall stability of the nipping loop, the fact that the second collar is weaker than it would have been in the case of a "common" Janus bowline does not matter much any more.
   In shot, I believe that the "Eskimo" Janus bowlines deserve a more careful examination by the knot tyers community.       

Dan_Lehman

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Re: Eskimo Janus bowlines
« Reply #10 on: April 09, 2013, 06:53:23 PM »
  In my compound-nub structures, it would be foolish to simply undo the outlying bowline and then consider what's left --in some fairly well-set state-- in terms of its isolated security

  That means your compound-nub structures are not two-stages structures,
where the second line of defence can hold, even if the first one has been crushed ...
However, the "Mirrored bowline", although it is a compound-nub structure
( is nt it that so ?), does not belong to this category, I believe...
  On the contrary, when I seek a "safe bowline", I search for a bowline that will hold,
even if its collar is loose, or it is cut off, or it is untucked altogether ! That is why
I search for self-stabilizing nipping structures, that will retain their integrity even
without the first stage/part of the collar structure - and/or with as little amount
of help from the whole collar structure as possible.

This is not my point : I was cautioning about how
to evaluate such an intended "compound" knotted
structure --to realize that IF that bowline component
could come untied, then it MUST be that the base
structure has loosened sufficiently to allow the
feed of material : now, how will such a loosened
base hold?  (Though I see here, too, some biased
thinking : why stop here to do this load-testing,
rather than keep on with the supposed loosening
and untying already conjectured?!)  (( One might
hope that rockclimbers are not entirely ignorant
over much duration of the state of their tie-in knot
--a longish loose tail should be an alert, sooner rather
than never. ))

But in large part, I'm coming to the conclusion that
what benefit the compound structures offer is in
general terms "a bunch of material/parts all together
such that it is very hard for the tail to slide out from
this mass of material, period!"

E.g., tie first the Eskimo bowline and feed its
tail --conveniently oriented, note-- up into casting
a bowline whose tail if tucked at least back into
the first knot (and possibly returned through the 2nd).
(This can appear much like the mirrored bowline.)

Maybe this mass of not-so-tight knotting will confer
some force absorption, to boot?!  Now, what about
chafe for such supposed tighten-&-loosen knotting?


--dl*
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X1

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Re: Eskimo Janus bowlines
« Reply #11 on: April 09, 2013, 10:04:14 PM »
tie first the Eskimo bowline and feed its tail --conveniently oriented, note-- up into casting a bowline whose tail if tucked at least back into
the first knot (and possibly returned through the 2nd). (This can appear much like the mirrored bowline.)

  Why "casting a [common] bowline", and not casting another, a second one, "Eskimo" bowline ?
  That is exactly what I have thought, and had tied the Two collars Girth hitch-ed "Eskimo" bowline, shown at the attached pictures.
  Plenty of mass !  :) The tail would have a hard time escaping from it...
  Now, this is a three stage compound knot !  :) Because it holds, even if you loosen or cut of both its collars, i.e, crush two out of its three defence lines  ! At the third and the fourth attached picture, the same knot without ( w /o  :) ) its collars...Holding !
  You are not going to figure out a safer knot than this, believe me. However, keep trying !  :)