Author Topic: Adjustable Loops  (Read 63013 times)

xarax

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ABoK#1045
« Reply #75 on: June 15, 2015, 04:03:01 AM »
   You were right again ( as ever !  :) ). I had mixed some files in my computer, and I had labelled wrong knots, with correct names, and vice versa ! :)
   It can capsize either in the variation you show, or in ABoK#1045.
   Your variation can be considered as a Blackwall hitch tied within an overhand knot. For a similar idea, see :
   http://igkt.net/sm/index.php?topic=4736.0
   I am not so sure that your original Luca s adjustable TIB loop, before it capsizes in the forms we show, is so unstable... We have to see how it will behave under heavy loading.
« Last Edit: June 15, 2015, 09:39:57 AM by xarax »
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xarax

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Luca s adjustable TIB lkoop
« Reply #76 on: June 15, 2015, 11:19:43 AM »
   So, here are the pictures of the Luca s adjustable TIB loop.
   It may be a little more convoluted than minimum, and so some of its nipping / gripping power may be "wasted" inside the nub s turns, and not utilized directly to immobilize the penetrating line. We have to test all those adjustable loops, and see. However, it may be not as unstable as you think - because, with small-sized nubs, it is relatively difficult for a riding turn to slide over or under another, and settle in position significantly different that the one it was meant to. With small things, even small steps are big !  :)
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alanleeknots

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Re: Load testing of various Bowline structures
« Reply #77 on: June 15, 2015, 12:37:45 PM »
Hi All,
         I didn't tie Luca s adjustable PET loop, I like this one  is more solid, I think it will jam on heavy load, I prefer the tail tuck it on the
         other side, will make a longer collar and may support little more load, 

         The third picture, this one is more complicated to tie, but two nice collar,
         I think this one
         will do well.   Tomorrow I going to test these loop here, and give you the result.
        謝謝  alan lee
« Last Edit: June 15, 2015, 01:04:21 PM by eric22 »

xarax

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Re: Load testing of various Bowline structures
« Reply #78 on: June 15, 2015, 01:06:42 PM »
   Noope ! Still the same problem- which you will never solve, if you do not understand it : Do NOT tie convoluted nubs when you want them to be as tight as possible / to nip/grip a tensioned penetrating line so much that they can immobilize it.
   In adjustable lops, simplicity is a functional property, it is almost a condition for their very existence ! It matters not only because, when the nub of an adjustable loop knot is as simple/less convoluted as possible, the knot can be tied and untied easily, it does not consume material without reason, it can easily be learned and remembered, and it can easily be inspected. It matters because it makes the nub tighter, and more secure ! Otherwise, a portion of the tension induced from the nipping/gripping structure will be "wasted" within its own turns, and there will remain less tension to directly immobilise the line.
   Now, the other thing you should remember ( in fact, the first thing one should realize, and keep in his mind ever since ), is the ANGLE of the L-shaped "handle", the angle at the returning eyeleg s first curve/deflexion  : It should be as close to 90, at least, degrees, as possible ! Otherwise the returning eyeleg will run the danger to SLIDE, and be dragged out of the nub. In both those loops you show in your post ( especially in the first...), this angle is too big/wide. See this angle in Luca s adjaastable TIB loop : it is 90 degrees sharp !
« Last Edit: June 15, 2015, 01:09:31 PM by xarax »
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xarax

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Re: Load testing of various Bowline structures
« Reply #79 on: June 15, 2015, 02:13:15 PM »
I don't need to test the Luca s adjustable TIB loop, just to look at it - and I can tell it will jam.

   You tell it because you see the overhand knot tied on the Standing Part before the eye - and you are right, of course.
   However, it may be GOOD for an adjustable loop to jam !  :) :) Or, it may be not so bad, as to be less secure and safe - because adjustable loops are NEVER 100% secure and safe : they will slip before they break.  By jamming, it will become a safe and secure eyeknot, although it consumes a very small, only, amount of material ( because of the absence of the "collar structure" ).
   I can imagine emergency situations where we want to tie an adjustable loop, as quickly as possible, which will become as secure and safe as possible when it will be loaded, and during the time it will remain loaded, and you do not bother with what will happen later, when you will not need it any more. When the task to hold something in/with the loop has been accomplished, and the loading is not applied any more, you may even cut off the whole end of the line where you had tied the loop !  :) Ropes are not so expensive any more...  :) The immediate need/demand for a secure, safe loop, NOW, may be much more important from the demand of retaining the original length of the rope, LATER ...
   In short, I believe that, for very secure and safe adjustable loops, jamming may be an acceptable risk, and, perhaps, when the load is really heavy, it may even be desirable !
 
« Last Edit: June 15, 2015, 02:15:39 PM by xarax »
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Mobius

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Re: Load testing of various Bowline structures
« Reply #80 on: June 15, 2015, 02:21:48 PM »
Hi Xarax,

              " EASY"    The Luca s adjustable TIB loop ( loose knot ) , I don't need to test, just look at it I can tell it will jam.
                   
                                I know my loops here will work will   support heavy weight,  "IS A VALID LOOPS" why not ?

                              謝謝  alan lee

You have trialled most of your loops from what I have read and if they work in the trial that knowledge is worth a lot. Your loops are fine Alan, keep doing what you are doing :)

Cheers,

mobius

Luca

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Re: Load testing of various Bowline structures
« Reply #81 on: June 16, 2015, 04:05:32 AM »
Hi xarax,

It can capsize either in the variation you show, or in ABoK#1045.

Yes,after manual capsizing+manipulating,the knot can be transformed in ABoK #1045!
I had not noticed this.

I am not so sure that your original Luca s adjustable TIB loop, before it capsizes in the forms we show, is so unstable... We have to see how it will behave under heavy loading.   

Well,yes,actually I meant that potentially the TIB version of the  knot has some problem regarding some accidental exchange of the position between the first curve of the standing part and the portion of rope adjacent to the first leg of the loop,and some potentially possibility of  accidental "haltering" of the portion of rope of the nipping structure that encircles the two legs of the loop.The ulterior variation of the TIB loop you show at  reply #77 seems to prevent at least the first of the possibilities described above.

With regard to the problem posed by Alan Lee at reply #78:I think that this type of adjustable loops "adjustable by the tail",if they are not designed for heavy loads(as in effect it is normally),they can afford to jamming a bit with their simple structures(but the Clove X adjustable loop perhaps jams a little too early!  ;) ).But maybe,in the hypothesis of a(static/gradual?) heavy loading a solution like this ( http://igkt.net/sm/index.php?topic=5381.msg35972#msg35972 ) seems to works even if apparently the convoluted knot in the standing part seems to prevent a total tightening of all the parts by manual force,because,applying a real load,the knot's nub actually grip around the tail,and some "redundant" portions of rope they can be used to be able to untie the knot.

                                                                                                                                  Bye!
« Last Edit: June 16, 2015, 04:19:09 AM by Luca »

xarax

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Re: Load testing of various Bowline structures
« Reply #82 on: June 16, 2015, 01:52:50 PM »
+ manipulating,

  I should had noticed this, indeed. Left alone, it capsizes only in the form you show - which is a pretty secure eyeknot : the Blackwall hitch within an eye and not within a rigid hook, is more secure than it looks !

a ( static/gradual ?) heavy loading

I prefer to describe this as a "slow loading".

   some "redundant" portions of rope can be used to [] untie the knot.

   In two ways : first, to offer "handles" / riding turns which can be pulled out and loosen it. And, second, by absorbing some tension which would had made it tighter !  :)  :) Nooope, I am not willing to tie a less minimal and less secure than possible adjustable loop, just to make it easier to untie ! To increase its mid-air stability, yes - such a sacrifice seems reasonable, and acceptable. So, if it turns out that the Clove X adjustable loop is much more unbalanced, in mid-air, than the double overhand knot-based one, then yes, I would prefer the later from the former- but NOT because it is more complex/convoluted, and so less tight/prone to jamming !

« Last Edit: June 16, 2015, 01:58:20 PM by xarax »
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xarax

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Re: Load testing of various Bowline structures
« Reply #83 on: June 16, 2015, 03:33:33 PM »
adjustable loops "adjustable by the tail"

   I believe that those are the more secure adjustable loops, and the only ones which can withstand heavy loading. There is no way any nipping/gripping structure tied on the Standing End after the eye can compete them in this. For two reasons :
   First, when the nipping structure is tied on the Standing Part before the eye, it is loaded with the 100% of the load from the one side, and with 50% from the other - while, if it is tied on the Standing Part after the eye, it is loaded only by its one end, and only with 50% of the load - so it can not nip / grip / immobilize the penetrating line as efficiently.
   Second, because there is no way, in the case of the "adjustable by the Standing End" loops, to force the direct continuation of this end to make such a sharp, almost 90 degrees turn, as we can force the direct continuation of the Tail End ( which is loaded by its one, only, side ) in the case of the "adjustable by the Tail End" loops. The angle of the "handle" from which the adjustable eyeleg is hanged, is of outmost importance : An even light grip, on the tip of a 90 degrees "handle", can immobilize the penetrating line much more effectively, than even the tightest nub with the strongest grip, around a wide curve of the Standing Part.
   The only way I have managed to figure out, is the way of the "Helical loops" - but it is a very difficult to tie an adjustable "Helical loop" which, although its helical coil does not turn around its core many times ( so we can adjust its position along the Standing Part easily ), it can be as secure as the Pretzel loop, for example.
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alanleeknots

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Re: Load testing of various Bowline structures
« Reply #84 on: June 17, 2015, 07:39:32 AM »
Hi All,   Just  another adjustable loop.     
           謝謝  alan lee
« Last Edit: June 18, 2015, 04:03:15 AM by eric22 »

alanleeknots

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Re: Load testing of various Bowline structures
« Reply #85 on: June 17, 2015, 10:33:13 AM »
Hi All,
        This loop here can transform to another loop, see reply #157  http://igkt.net/sm/index.php?topic=4125.150

          謝謝  alan lee

        "June-21-2015 add another loop here,(second photo)this cute little knot belong to this group of knots here."
        "june-22-2015  add another cute loop (third photo).
         one more adjustable loop.(fourth photo)
« Last Edit: June 22, 2015, 08:51:12 PM by eric22 »

Mobius

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Re: Load testing of various Bowline structures
« Reply #86 on: June 17, 2015, 10:45:58 AM »
Hi All,   Just go ahead tie this beautiful loop you self .
           Please no comment, wait till I finish writing  what I have to said, also a few more pictures to add it on here..
            and then..........
     
           謝謝  alan lee

I tied it, I am not sure I got what I was supposed to get though ;)

Cheers,

mobius
« Last Edit: June 17, 2015, 01:41:57 PM by mobius »

agent_smith

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Re: Load testing of various Bowline structures
« Reply #87 on: June 17, 2015, 04:05:18 PM »
Alan - I keep ending up with a 'single eye' variant of the 'Karash' Bowline... I have attached some old images I found on my computer.

Only named them 'Karash' since he apparently claims that he 'discovered' a 'TIB' version (what he calls the Karash double loop). The tying method depicted is based around #1047 but is completely unnecessary as it can be tied similarly to #1080 (by first creating an extra twist in the nipping structure). Refer this website  https://en.wikipedia.org/wiki/Karash_double_loop

Of course, I could be tying this incorrectly and arriving at the wrong result!

Dan_Lehman

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Re: Load testing of various Bowline structures
« Reply #88 on: June 17, 2015, 06:50:46 PM »
Alan - I keep ending up with a 'single eye' variant of the 'Karash' Bowline...
I have attached some old images I found on my computer.

Only named them 'Karash' since he apparently claims that he 'discovered' a 'TIB' version
(what he calls the Karash double loop). The tying method depicted is based around
#1047 but is completely unnecessary as it can be tied similarly to #1080 ...
Indeed Mr. Karash long ago submitted to me his discovery
and subsequently got it tested and presented it on his own
WWWeb site.  I likened it to doing to what Hansel&Gretel
call --pp.36/7, #197 (on Plate #11, "Bowlines")-- "the Twist
Bowline" but in a bowline in the bight variation. ["H&G" = EKFR]

There is the question of which end to load, and so on.
And one can take this foundation and go with some
"wraps" as have I & Alpineer with our locktight / tresse
barrel
knots --though, in the base, wraps do not
appear (one could regard this "base" stage, then,
as "degenerate", similarly the overhand vis-a-vis
its "multiple" forms which can have wraps but not
the simple knot base.  (And why I favor using the
starting points to counting monikers "double, treble,..."
to be "grapevine" & "strangle", for they have *one*
wrap, and fit the implications of "double" for two
and so on, unlike "double fisherman's" which has
ONE not two.)


--dl*
====

xarax

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Re: Load testing of various Bowline structures
« Reply #89 on: June 17, 2015, 07:29:07 PM »
   Alan, I had tied those three adjustable loops, but I had succeeded to "fold" into compact nubs only two of them ( the first and the third ).
   The action of the Standing Part s first curve on the penetrating line is what it should be : direct, and very efficient. However, the continuation of the returning eyeleg does not contribute to the "locking" of this line - it goes straight to the collar, so, when it comes "down" from there, the tension which runs along it has been diminished.
   The good news are :
    a, the "right" angle of the "handle", at 90 degrees relatively to the axis of the knot,
    b, that the penetrating line is squeezed, by the Standing Part s first curve, on one, or two segments placed at 90 degrees, the "right" angle ( see the red arrows in the B#W picture ).   
     We have to test all those adjustable loops under as heavy a load as they can take - and I suspect that the material would play an important role...
« Last Edit: June 17, 2015, 07:57:03 PM by xarax »
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