Author Topic: Midspan bends.  (Read 43860 times)

Dan_Lehman

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Re: Midspan bends.
« Reply #30 on: January 10, 2012, 07:26:48 PM »
the fact they can be tied in the bight is what makes [the Constrictor] so versatile.

Although one can see this as *seeing* a constrictor where
the nature of that binder is lost.  (The clove hitch also can
lead to a nice, quickly tied (in the bight) eyeknot.)

   You forgot to mention that the Constrictor can also serve as a fine noose-hitch,

One might prefer to use it with the other *end* loaded,
so, making a turn/half-hitch and then finishing away
from the hitched object (turning near, reaching far,
vs. vice versa as you show).  Both look interesting.

--dl*
====

xarax

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Re: Midspan bends.
« Reply #31 on: January 10, 2012, 10:57:31 PM »
One might prefer to use it with the other *end* loaded,

   You mean to swap the standing end for the tail and vice versa ? I have considered this "inverted" loop, and I have decided that ; 
1. It is better to have the helical coil - that surrounds the Constrictor and thus multiplies its nipping force - tensioned by the standing end s strong pull, rather than by the eye leg of the bight s weaker one.
2. the way the tail is exiting the nub of the inverted knot is not very satisfactory... because, in this last line of defense against slippage, this last tuck, the tail is not nipped very tightly. ( When a tail is nipped in more than one points into a knot s nub, it is better to arrange things so that it is nipped harder and harder as it proceeds closer and closer to the exit - and not the opposite. That way there would be no slack left alongside the tail s path through the knot, and the knot itself would be forced to take a more compact shape).
« Last Edit: January 11, 2012, 06:06:08 AM by xarax »
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knot4u

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Re: Midspan bends.
« Reply #32 on: January 11, 2012, 12:00:29 AM »
Here's a boring solution:  Hold the two ropes side-by-side as if the ropes are one.  Tie a Butterfly loop on a bight as if the ropes are one.  Tied correctly, you'll have two loops and four ends.

Advantages:
  • You already know it if you know the Butterfly Loop on a bight
  • Difficult to tie wrongly
  • You don't need access to any end
  • Can be pulled at all four ends, any combination of forces (according to my brief testing)
  • Possible to bend FOUR separate ropes with this same knot.  To understand this, imagine cutting the Butterfly loops here and then untying.  Note that if you bend four ropes together the way I propose, you'll have 8 ends and no loop.
  • Not jam-prone

Disadvantages:
  • Requires more rope than most other solutions here
  • Not as elegant looking as most other solutions here (depending on your taste)
« Last Edit: January 11, 2012, 12:57:20 AM by knot4u »

xarax

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Re: Midspan bends.
« Reply #33 on: January 11, 2012, 06:25:33 AM »
  • Requires more rope than most other solutions here
  • Not as elegant looking as most other solutions here (depending on your taste)

   An understatement ! :) In the first place, you have tied a different knot, a TIB double loop - or a double line midline double loop. Who ordered that ? Then, economy of material is not a matter of taste, one can measure  it, it is not belonging to the "de gustibus et de coloribus" subjective realm.
   Now, there are dozens of midline, TIB single or double loops known, and I guess that there are dozens that are unknown. I doubt that the Alpine Butterfly would be the most economical, or the less jam-prone.  We should measure the material used by all those knots, and see.
    Due to their high symmetry, many of the TIB single or double loops are very interesting knots, and they can be used as bases for loops and bends, as you have noticed. However, if a knot is already bulky as an end of line loop, the same knot would appear much more bulky in the middle of a tensioned line !  :)
« Last Edit: January 11, 2012, 06:37:56 AM by xarax »
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knot4u

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Re: Midspan bends.
« Reply #34 on: January 11, 2012, 06:52:10 AM »
  • Requires more rope than most other solutions here
  • Not as elegant looking as most other solutions here (depending on your taste)

   An understatement ! :) In the first place, you have tied a different knot, a TIB double loop - or a double line midline double loop. Who ordered that ? Then, economy of material is not a matter of taste, one can measure  it, it is not belonging to the "de gustibus et de coloribus" subjective realm.
   Now, there are dozens of midline, TIB single or double loops known, and I guess that there are dozens that are unknown. I doubt that the Alpine Butterfly would be the most economical, or the less jam-prone.  We should measure the material used by all those knots, and see.
    Due to their high symmetry, many of the TIB single or double loops are very interesting knots, and they can be used as bases for loops and bends, as you have noticed. However, if a knot is already bulky as an end of line loop, the same knot would appear much more bulky in the middle of a tensioned line !  :)

Yes, indeed...It's quite bulky, but it's still a good default solution if the hard-to-remember preferred knot let's you down.

By the way, if joining 4 ropes (8 ends), the Butterfly solution I described in my last post is relatively elegant.
« Last Edit: January 11, 2012, 06:59:32 AM by knot4u »

Dan_Lehman

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Re: Midspan bends.
« Reply #35 on: January 11, 2012, 07:38:24 AM »
One might prefer to use it with the other *end* loaded,

   You mean to swap the standing end for the tail and vice versa ?

No, I referred to your aside about the "noose-hitch", not eyeknot.
One connects the SPart's flow into the constrictor to its other end.


--dl*
====

Dan_Lehman

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Re: Midspan bends.
« Reply #36 on: January 11, 2012, 07:59:01 AM »
In the first place, you have tied a different knot, a TIB double loop - or a double line midline double loop.
 Who ordered that ?

Just a consequence of the situation (no ends).

Quote
Now, there are dozens of midline, TIB single or double loops known,
and I guess that there are dozens that are unknown. I doubt that the Alpine Butterfly
would be the most economical, or the less jam-prone.

???  How about naming some few others to compare?!

I had my doubts about Knot4U's suggestion working for
the ends on the *same side* being pulled against each
other, but (also on brief checking) they seem to do so
(forming, in a sense, sorts of offset water knots (EDK)
in effect, with added bulk that seems to resist distortion).


--dl*
====
« Last Edit: January 12, 2012, 08:05:56 PM by Dan_Lehman »

xarax

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Re: Midspan bends.
« Reply #37 on: January 11, 2012, 11:53:22 AM »
... is relatively elegant.

   I agree, of course, that even a very  bulky knot, can be very  elegant ! Elegance  has to do with symmetries and the harmonious flow of lines, not with the economy of material. However, I ,personally, would rather choose a thin/slim elegant knot, than a thick/fat elegant one !  :)

[/quote]
In the first place, you have tied a different knot, a TIB double loop - or a double line midline double loop.
 Who ordered that ?
Just a consequence of the situation (no ends).

   I mean, the two additional loops ( slack bights ), hanging from the knot s nub. A utilitarian thing for the wet laundry, perhaps, but that was not the prescription of this thread I am afraid...

???  How about naming some few others to compare?!

  I am not going to repeat here some numbers of the ABoK s relevant long chapter on double loops you know very well ! I have a feeling that there are dozens more TIB double loops possible, because, although we can not use the two ends, we can manipulate the two bights in many ways ( so they get entangled the one to the other, around the two parts of line and possibly through some nipping loops formed  in those parts ).(See one possible TIB double loop midline "base", at the attached picture. The over-under relation of an "eye" s legs can be reversed). I was impressed that the first time I tried my hand on double loops, I met a new one ( Beginner s luck ?  :) (1). It has happened to me to have a glimpse of that seemingly endless landscape that is waiting for us there, but I just do not have the motive to exploit it for the time being - I have other priorities. Anyway, from the practical point of view, a new mid line double loop is not such an urgently needed knot, I guess...
Let us first finish this dirty bowline job :)

1. http://igkt.net/sm/index.php?topic=3571.0
« Last Edit: January 11, 2012, 03:55:21 PM by xarax »
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xarax

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Re: Midspan bends.
« Reply #38 on: January 11, 2012, 12:58:43 PM »
One might prefer to use it with the other *end* loaded, so, making a turn/half-hitch and then finishing away from the hitched object (turning near, reaching far, vs. vice versa as you show).  Both look interesting.

   One might remind DL that there are pictures taken at 1826 and 1838, time flows to one direction (unfortunatelly...), and there is knot eternal life..

   I think that the first Constrictor noose-hitch is more of a noose, and this second one is more of a hitch...
« Last Edit: January 11, 2012, 01:57:04 PM by xarax »
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knot4u

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Re: Midspan bends.
« Reply #39 on: January 12, 2012, 07:34:54 AM »
Hey, what the heck is the knot in a rope cargo net?




Dan_Lehman

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Re: Midspan bends.
« Reply #40 on: January 12, 2012, 08:13:38 PM »
Hey, what the heck is the knot in a rope cargo net?

In general --i.e., in netting, in general--, such knots are *mesh knots*
or *net knots*, as a class.  In appearance (from your images), these
look to be *mid-line hitches* --i.p., overhand hitches around the
crossing line.  In actuality, we might find that the apparently hitching
line at one point is reeved through the lay of the crossing line
--which helps to stabilize location of the joint.

--dl*
====

xarax

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Re: Midspan bends.
« Reply #41 on: January 20, 2012, 01:40:36 PM »
  I think I saw a pussy cat... ( or a puppy dog  :) ) complaining about the complexity of tying the Adjustable Constrictor loop...so I tried to figure out a simpler knot, based on the same idea. It comes out that if we wish to use a less cnvoluted ( than the Constrictor ) knot on the attached line, we have to use more than one coils on the main line- otherwise our knot will slip alongside the direction of the pull. See the attached pictures for such a simpler loop. Given the simplicity of the knot on the attached line - just two non-entangled bights, each one tied as a collar around each pair of ends - we now need at least two coils to secure the knot - and it might even turn out that we better use three, if we use a very slippery material.   
   Nevertheless, the knot is as simple as it can be, and I have named it so one can not forget how to tie it, even if he does not try to remember it...Form two coils on the standing part, then pass the working end/tail through them, in order to form two collars. To have as secure a loop as possible, and depending upon the material used, you might have to pull the two ends of the collar pair at the end, so the knot on the attached line is shortened, and the coils on the main line approach, even touch each other. The interested reader is called to try this knot with a variety of materials, with two or three coils, and with a more or less shortened knot, and report his findings.

This line of though can be explored even further, I believe, as I have already mentioned at the first post of this series:
" I have only recently realized that, if we have a complex enough, effective enough structure on the attached line, we do not need a closed nipping loop on the main line !
... it turns out that any curve... can, in fact, be utilized to prevent any slippage of the attached line alongside the main line.
... I am sure we can find even simpler midline bends than the one shown here... and the interested reader is called to try his own hand. "

   
   
   
« Last Edit: January 20, 2012, 01:41:30 PM by xarax »
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xarax

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Re: Midspan bends.
« Reply #42 on: January 21, 2012, 09:27:41 PM »
   One might well ask : why do we need this "2 coils-2 collars" bowline-like loop in the first place, that may be quite simple and easy to tie, but it is more complex and more difficult to tie from the common bowline itself nevertheless - or even more complex and more difficult ti tie from the "Janus" 2- collars versions of the common bowline ? 
   I admit that I have a hope I have not mentioned , because I thought it would have been a little premature... I hope that this loop will be stronger  than the common bowline or the 'Janus" 2-collars versions of it...because of the gentle curve the standing part follows as it enters the knot s nub. This wide helical path, without the self-intersections we have when we use closed nipping loops, might be proved beneficial for the overall strength of the knot. Of course, I keep my fingers crossed on this... and I wait the results of the destructive tests I plan to perform, on the sooo many bends and loops we already have... 
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knot4u

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Re: Midspan bends.
« Reply #43 on: February 06, 2012, 06:05:40 AM »
Four Corners Knot is one of the most elegant solutions to the OP.
« Last Edit: February 06, 2012, 06:11:54 AM by knot4u »

xarax

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Re: Midspan bends.
« Reply #44 on: February 06, 2012, 08:28:44 PM »
Four Corners Knot is one of the most elegant solutions to the OP.

I am afraid I do not remember or know this knot...Could you please help me here ?
A diagram, picture or reference would be most welcomed.
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