Author Topic: Adjustable Loops  (Read 47043 times)

Dan_Lehman

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Re: Load testing of various Bowline structures
« Reply #120 on: July 14, 2015, 07:15:23 AM »
  As I had said to Alpineer (1), I do not like sharp U turns,
Nor do some ropes --i.p., hard-laid ropes, old stiff ropes,
built-to-be-tough caving ropes.  In which case, one must
go to Plan B!


--dl*
====

agent_smith

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Re: Load testing of various Bowline structures
« Reply #121 on: July 16, 2015, 12:33:13 AM »
Hi Alan (Alan Lee),

I just want to personally thank you for your incredible work and contribution to our collective knowledge bank :)

I think you are an unacknowledged genius!

I will photograph some of your fantastic creations as soon as possible in high resolution format.

I am already using some of them on a regular basis...

Sincerely,

Mark Gommers

alanleeknots

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Re: Load testing of various Bowline structures
« Reply #122 on: July 20, 2015, 02:42:51 AM »
 Hi All,
        Mark Thanks for the kind words, and the hard work. I am just a hard working knots tyer, who like to share my knots work,
        still far from genius.
        I have another interesting loop here, is a adjustable and quick release loop, only need one tuck on the tail eye leg to
        form the loop.
        Tomorrow if there is a chance during lunch break, I like to do some extreme load test with the crane.
       
        謝謝  alan lee.
« Last Edit: July 20, 2015, 06:55:21 AM by eric22 »

alanleeknots

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Re: Load testing of various Bowline structures
« Reply #123 on: July 26, 2015, 06:35:27 AM »
Hi All,
         For the softer rope, easy to dress the loop tight, all three test are holding very well and easy to untie.

          謝謝 alan lee.


alanleeknots

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Re: Load testing of various Bowline structures
« Reply #124 on: July 26, 2015, 06:37:31 AM »
More photos.
« Last Edit: July 26, 2015, 06:49:42 AM by eric22 »

alanleeknots

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Re: Load testing of various Bowline structures
« Reply #125 on: July 26, 2015, 06:42:36 AM »

Hi All,
          For stiffer rope, because of the two one diameter rope sharp turn, just can not pick up all the slack by hand.
          7/16 Blue water rope loaded at 2000 lbs. just ok to untie, at 2500 lbs jam hard.
          8mm Blue water accessory cord loaded at 1200 lbs, one side of the loop just able to untie,  the other side jam hard.

           謝謝 alan lee.

xarax

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Re: Load testing of various Bowline structures
« Reply #126 on: July 26, 2015, 11:09:11 AM »
   As I had said many times, at the end of the day the most important thing is the angle of the "handle" ( = the angle between the returning/second eyeleg and the Tail End). If the angle is wider than 90 degrees, as it happens here, however tight is the grip, it can not be very efficient : If we do not use many ( parallel or cross-gartered)  wraps, as in the climbing friction hitches or in the rat-tail-stopper, we can not immobilize a straight line...
This is not a knot.

alanleeknots

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Re: Load testing of various Bowline structures
« Reply #127 on: July 30, 2015, 11:16:44 PM »
Hi All,
        Xarax Thanks you very much.

            謝謝 alan lee

alanleeknots

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Re: Load testing of various Bowline structures
« Reply #128 on: August 02, 2015, 03:18:07 AM »
Hi All,
         This is a nice looking, solid well secure double collars loop.
         The nipping loop deliver more percentage of compression force then the nipping force
         to secure the loop. Beside the standing part,  the two eye legs are able to apply pressure to the nob.   
         All three tests are holding very well, and easy to untie.
       
         謝謝  alan lee

alanleeknots

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Re: Load testing of various Bowline structures
« Reply #129 on: August 02, 2015, 03:20:01 AM »
Load test photos.

xarax

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Re: Load testing of various Bowline structures
« Reply #130 on: August 02, 2015, 09:53:48 AM »
1. When you say "loaded heavily", what do you mean ? Could you, please specify the load as a percentage of the MBS of the rope ? Is it close to 50% ( which is what I would call "heavy load" - if it is closer to 33 %, I would call it "moderate", and if it is closer to 25%, 'light" ).
2. I would nt call it a "double collar" (=two collars) loop. The one ( the first ) leg of the collar is "coiled", that is, it makes a helical turn, but there are no two U-turns, the one after the other ( a N-like collar ). And the two legs are not crossed, like it happens in the case of the " cross-gartered" bowline (1). In particular, in the genuine "double collar" bowlines, if you, accidentally, un-tuct the second collar, you are still left with the first, which still works - while in your loop shown here... well, you are still left with a helical turn, the simplest helical "knot", which you pray it will hold ! :)
3. I am not sure that the total nipping force, delivered by the closed nipping turn tied on the Standing Part, and the open ( helical ) turn tiedon the returning / second leg of the eye, deliver more gripping / nipping power than a triple (=three nipping turns) bowline, as the Tresse coiled S.Part shown by Alpineer (2), or the even simpler Triple bowline shown by me (3)(4) - which have the additional advantage that their nipping structures are self locking. ( In fact, it looks like a transformation of those bowlines, where the one nipping turn of the "nipping structure", tied on the Standing Part has been replaced by one nipping turn of the "collar structure", tied on the returning / second eyeleg ).
4. I believe it is too complex - although easy to tie and untie. I do not see a clear "pattern" in tying it, or in its final form which would allow to inspect, memorize and remember it easily.
5. Having said that, it is clearly a new concept, where, although the loop is not based on a bend ( like the Tweedledee bowline - but there are many other, "simpler" bends not based on interlocked overhand or fig.8 knots, which can be turned into nice symmetric bowline-like loops ), nevertheless it utilizes the nipping action of both eyelegs.

1. http://igkt.net/sm/index.php?topic=4283.msg35800#msg35800
2. http://igkt.net/sm/index.php?topic=5357.msg36131#msg36131
3. http://igkt.net/sm/index.php?topic=5357.msg36605#msg36605
4. http://igkt.net/sm/index.php?topic=5418.msg36587#msg36587
« Last Edit: August 02, 2015, 10:07:24 AM by xarax »
This is not a knot.

alanleeknots

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Re: Load testing of various Bowline structures
« Reply #131 on: August 04, 2015, 07:44:14 AM »
Hi All,
         Xarax Thanks for your reply, I don't have scale at home I just pull it as hard as I can, may be I should call it in between moderate
         and light then.
         Anyway I test it again with 1-4" solid braid nylon rope and 6mm Blue water rope, and also with another variation loop, this time
         I can call it close to 50% of MBS.
         Both loops are holding well and easy to untie.

          謝謝  alan lee

alanleeknots

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Re: Load testing of various Bowline structures
« Reply #132 on: August 04, 2015, 07:48:12 AM »
Load Test photos.

alanleeknots

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Re: Load testing of various Bowline structures
« Reply #133 on: August 05, 2015, 08:22:24 AM »
Hi All,
          This idea work on the bowline line nipping loop too.
          Interesting loop, if you just twist the top part of the bowline nipping loop it become loop 1.

          謝謝  alan lee
« Last Edit: August 05, 2015, 09:51:05 AM by eric22 »

xarax

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Re: Load testing of various Bowline structures
« Reply #134 on: August 05, 2015, 10:32:02 AM »
   There are two ways to spoil this idea :
   First, the double coil on the returning/second eyeleg. IMHO, it is an overkill. The second helical coil will always remain more lose/less tight than the first, and it will not contribute much to the gripping / nipping of the second leg of the collar. On the contrary, it may absorb some of the tension we want to reach up to the collar, because we do mot want a lose collar either ! One may say that a second coil makes the nipping loop wider, but this is not very true : it just makes it more elongated, more oval-shaped - the Standing Part s first curve remains almost as wide as it would had been had you used one, only, coil.
   Second, to place the coil(s) horizontally, as you do, rather than vertically. A more vertically oriented coil can become more tight ( there is no tension "wasted" by the generation of friction forces within its segments, due to unnecessary twists ), while, at the same time, it allows the incoming tension to pass through it, and reach the collar. You need this coil to grip / nip as tightly as possible, but to remain a "nipping loop" ( that is, a loop with two ends almost equally loaded ), not a half hitch !
   I believe you had tied a loop like the one shown in the attached pictures in the past. Your collection has gone out of the roof, you need some housekeeping ! ;)
« Last Edit: August 05, 2015, 10:54:02 AM by xarax »
This is not a knot.