Author Topic: New hitch?  (Read 30046 times)

richardpeterson

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New hitch?
« on: February 27, 2012, 11:04:41 PM »
I'm a new member and this is my first post. I've developed a hitch that I haven't seen before that appears to have some very useful properties. First, the knot:

http://imgur.com/a/wNBuu

Where I've looked
I looked through the chapters on hitches in ABOK. This hitch is related directly to the Ossel hitch (no ABOK #), so I searched online for variations of the Ossel hitch. I came up with nothing.

Development
I needed a hitch that could be tied securely in surgical tubing. Surgical tubing is rubbery elastic tubing that is usually quite powdery. I tried every hitch I know - flipping through ABOK. Every hitch I tried failed quite easily due to slippage. Some of these knots can be made to work if the tubing was wet and pulled up very tight to set the knot.

The mode of failure for most wrap-based hitches (from clove hitch all the way through larger hitches like the boom hitch) is that, due to the elasticity of the material, the standing part lifts up the other parts of the knot as it is loaded, and this releases the nip. Other hitches just slide undone with surprising ease.

I came up with this hitch in order to avoid having the standing part release the nip when loaded. I can tie it quite loosely in surgical tubing and load it, and it does not slip through hundreds of rounds of loading.

Testing
I tied this hitch in all the line I had around the house - poly solid braid, dynamic climbing line (not sure the material), surgical tubing, small poly stuff, poly 3-strand rope. I hitched each line to poles and rings of varying diameter - some poles as large as about 20 times the diameter of the rope and some as small as about 1 diameter of the rope. I tested it by jerking it violently perpendicular to the pole with my own strength a few hundred times for each material and measuring the tail for slippage. I did not encounter slippage.

I haven't tested in monofilament or other slippery or elastic line except surgical tubing.

I did not test for strength.

I encountered one failure. I hitched some small solid poly braid to a pole leaving about 3 inches of tail, and jerked the standing end side to side, repeatedly and rapidly loading the line parallel to the pole, back and forth - first toward one end of the pole, and then toward the other. The knot loosened and came undone after about 50 jerks.

Other notes
This knot is the same as the Ossel hitch, only with a round turn at the beginning instead of a single turn. The ossel hitch fails in the surgical tubing.

This hitch seems to have some frictional properties (it generally resists sliding), but I doubt it performs like a real friction hitch.

It is not easy to tie under load, since the final tuck requires lifting the loaded turn.

It seems to stay secure when not carefully pulled up - that is, when the final nip is allowed to move up away from the bottom of the hitch. However, I don't tie it that way because it seems sloppy and I suspect it isn't as secure.

I call it the "fist hitch", because it reminds me of a fist hanging onto a pole. If it has another name already, I would love to know.

Questions

Have you seen this hitch before?

It seems very secure to me in my informal testing. Does anybody have any opinion on its security?

What about its strength? With that sharp bend in the rope, I wonder how strong it is.

Thank you for your time,

Richard Peterson




roo

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Re: New hitch?
« Reply #1 on: February 27, 2012, 11:38:54 PM »
Thanks for sharing.

I was trying this in some small elastic bungee around a one inch diameter steel bar.  The introduction of a little swing caused things to slither and slip.  I don't know if this would translate into surgical tubing.  Elastic material hitching has no shortage of difficulties.

I'd like to have you consider some options for your aim as I continue to look at your creation.  You can try them with or without added turns to see if they meet your needs.

One is the Gnat Hitch:
http://notableknotindex.webs.com/gnathitch.html

The other is a variant of the Slipped Buntline Hitch, shown at the bottom of this page:
http://notableknotindex.webs.com/slippedbuntline.html

If you're open to a loop solution, you could also give a Zeppelin Loop a try:
http://notableknotindex.webs.com/zeppelinloop.html
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xarax

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Re: New hitch?
« Reply #2 on: February 28, 2012, 12:56:30 AM »
   I have noticed that the previous author recommended a number of knots, all of which are entirely irrelevant to yours...The Gnat hitch is a very elementary hitch, not bad for its simplicity, but not a secure hitch either, by any means. The slipped Buntline is better, but not at the top of its class. For the best such hitch-noose, see the "Buntline extinguisher", i.e. the Constrictor-tied-around- the-standing-part  (1). The so called "Zeppelin loop" in not even a hitch... It is an end of the line fixed loop, much worse, as a knot, from its parent beautiful symmetric bend, the Zeppelin bend - and only one of the hundreds of secure bends we have that can be transformed, in a not-so-clever way, into end-of-line loops.
   To really see what is a gripping hitch, and compare with the Ossel hitch  or yours, search under the name "gripping hitch", in this Forum. Compare it also with the ABoK#1740. (2)

1)  http://igkt.net/sm/index.php?topic=3133
2)  http://igkt.net/sm/index.php?topic=3016
« Last Edit: February 28, 2012, 01:11:17 AM by xarax »
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roo

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Re: New hitch?
« Reply #3 on: February 28, 2012, 01:10:17 AM »
   I have noticed that the previous author recommended a number of knots, all of which are entirely irrelevant to yours...The Gnat hitch is a very elementary hitch, not bad for its simplicity, but not a secure hitch either, by any means. The slipped Buntline is better, but not at the top of its class. For the best such hitch-noose, see the "Buntline extinguisher", i.e. the Constrictor-tied-around- the-standing-part  (1). The so called "Zeppelin loop" in not even a hitch... It is an end of the line loop, much worse, as a knot, from its parent beautiful symmetric bend, the Zeppelin bend - and only one of the hundreds of secure bends we have that can be transformed, in a not-so-clever way, into end-of-line loops.
   
The poster is looking for hitches for elastic surgical tubing, and the links I gave him may be suitable to accommodate that elasticity.

The Gnat Hitch is more secure than a Buntline Hitch, which is generally considered to be secure.  Since you usually shun testing, I'm wondering if you've even tested it in rope, bungee, or surgical tubing.

I think I already mentioned that the Zeppelin Loop is a loop.  It's lack of interaction with the hitching object helps it avoid some of the pitfalls of the extreme distortion that arises from hitching with highly elastic material.  Your claiming it being "much worse" than the parent bend doesn't make it so.  You don't even bother to specify the ways it is "much worse", because you know it it'll expose the weakness of your fallacious claim.

Your thinly-veiled trolling is tiresome.
« Last Edit: February 28, 2012, 01:24:44 AM by roo »
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SS369

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Re: New hitch?
« Reply #4 on: February 28, 2012, 02:28:30 AM »
Hi Richard and welcome.

Nice mod to the Ossel hitch as I see it. That it works with surgical tubing is small surprise. I personally would think that creep would work it loose, but since I don't have any tubing available I'll have to reserve my own judgement till I do.

May I inquire as to the use of this? Does the use mean that there will be no other directional loading, e.g., angular or parallel?

In addition to what has been suggested for your consideration I add the Lobster Buoy hitch and the Groundline hitch. Both of these handle multi-directional loading.
The Constrictor knot may work as another possibility. Even a Timber hitch could work.

As for the strength of this. That is very relative to the material used and the severity  of conditions the affair will see. I think with the tubing the security is the priority.

So please give us the use if you care to and we can go a lot longer with that information.

Thank you for bringing this modification to us.

SS

xarax

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Re: New hitch?
« Reply #5 on: February 28, 2012, 02:34:42 AM »
Your thinly-veiled trolling is tiresome.

I do not respond to such...
This is not a knot.

knot4u

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Re: New hitch?
« Reply #6 on: February 28, 2012, 02:43:31 AM »
I have not tried this hitch in surgical tubing, but it holds securely in paracord, boot lace, and other similar cordage. Regarding the strength, yes there's the sharp turn, but the pressure at that turn seems to be lessened by the Round Turn and the nipping. At first, I thought there was a jamming issue, but now I see loosening is not too difficult: just yank on the working end and then pry the knot loose.

The Sailor's Hitch is the first knot I thought about for comparison. Is that a no-go for this application?
« Last Edit: February 28, 2012, 02:51:10 AM by knot4u »

richardpeterson

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Re: New hitch?
« Reply #7 on: February 28, 2012, 04:16:57 AM »
Thanks for the responses!


Roo:
I grabbed a 1" diameter steel bar to test with.


The gnat hitch suffered some initial slip, but seemed to settle into a stable spot, and survived being tested a few hundred tries without slipping. So did the slipped buntline variant. Neither of these really choked up around the pole as they would have with rope or bungee. Because of the rubbery nature of the tubing, they always opened up as loops when loaded. That is, the knot stretched away from the pole, allowing the hitch to slide or roll along the pole. I thought maybe starting with a round turn would alleviate these problems, but it doesn't. When loaded at any kind of angle, the round turn rolls along the pole, twisting itself up.


I couldn't reproduce any slippage when swinging the load on the knot I posted using the surgical tubing. I don't have any bungee available, so thank you for advising that it slips.


Thanks for suggesting the gnat hitch, also. I'll keep it in mind for other stretchy stuff.


Xarax:
Thank you for the suggestions.


I tried ABOK #1740, but it spilled pretty quickly. I worked it up as tightly as I could without wetting the line, and aggressive loading in multiple directions worked the 4" tail I left free in a few minutes.


knot4u:
Thank you for the assessment. I'm glad you didn't find it to jam.

The sailor's hitch sounded like a sure winner to me, too. Unfortunately, it works its way around, pulling the knot progressively around the back of the pole (at least my round pole using my surgical tubing), and comes free.


All:
I originally found this knot while looking for a hitch that would suit physical therapists. My wife's physical therapist uses surgical tubing for exercises. He ties it onto equipment for long term use in his facility. The loads are no more than about 100 lbs, but they are repeated and in varying directions. The knots, I'm sure, are not always inspected prior to use...


After considering all your suggestions and trying most, I think the ideal knot would stay put on the pole after being tied, like the constrictor knot, ossel hitch and sailor's hitch. Loop knots (or knots that act like loop knots when tied in surgical tubing) are not ideal.


It would also be easy to fair in surgical tubing. I know most people probably don't have surgical tubing lying around, but let me tell you - it is not fun to knot in. It took me a good solid minute to fair up the gnat hitch after tying.


Ideally, it would also be somewhat easy to tie - or at least hard to get wrong. Foolproof, so to speak. Physical therapists work in people's homes, and they hitch tubing to whatever they can find. They sometimes send tubing home with patients for them to use. The easiest hitch that would be secure, stay put where tied, and generally not be fussy would be ideal.


That said - I'm excited about the hitch I posted, whether it turns out to suit my original purposes or not. It's really fun having knot experts and other knot lovers give it a go and see if it's any good! I'd love to hear any other suggestions about a knot for physical therapy use, or other feedback on the hitch I posted.


Thanks to all!

roo

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Re: New hitch?
« Reply #8 on: February 28, 2012, 06:23:28 AM »
....Ideally, it would also be somewhat easy to tie - or at least hard to get wrong. Foolproof, so to speak. Physical therapists work in people's homes, and they hitch tubing to whatever they can find. They sometimes send tubing home with patients for them to use. The easiest hitch that would be secure, stay put where tied, and generally not be fussy would be ideal.


That said - I'm excited about the hitch I posted, whether it turns out to suit my original purposes or not. It's really fun having knot experts and other knot lovers give it a go and see if it's any good! I'd love to hear any other suggestions about a knot for physical therapy use, or other feedback on the hitch I posted.


Thanks to all!
Thanks for the feedback.  As you could guess, surgical tubing is not something most of us just have laying around, so it's nice to get a report back on some of the behavior.

One thing that comes to mind is that you might be able to improve the performance of many simple hitches by tying a stopper knot near the end of the tubing, and then letting the hitch slither toward the stopper until it, well, stops.  Since you're the one with the surgical tubing right now, you'll have to be the one to conduct the testing.

Another option may be to bend the tubing to a short length of normal rope or cord, such that hitching is no longer a challenge because you can let the rope assume the hitching role.  A Zeppelin Bend may be appropriate.

I hope you'll keep reporting back if you find something you consider to be ideal for your application.
« Last Edit: February 28, 2012, 07:27:35 PM by roo »
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Hrungnir

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Re: New hitch?
« Reply #9 on: February 28, 2012, 08:54:06 AM »
I've earlier used roos methotd successfully with bending rope and athletic rubber bands. However, the stretchy nature of rubber bands will jam horrybly around the rope, and is almost impossible to untie. I don't know wether this will be an issue when using medical tubing. My solution was to use a Slipped Sheetbend. In the image below, the rubber band is illustrated in grey and the the rope in white.

« Last Edit: February 28, 2012, 08:56:25 AM by Hrungnir »

xarax

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Re: New hitch?
« Reply #10 on: February 28, 2012, 10:19:43 AM »
  We have had a discussion in this forum, about knots tied in medical practicing in :
http://igkt.net/sm/index.php?topic=3659.0
  Try the knot suggested there ( shown at the attached picture ).
  One has to distinguish the hitches that are designed to withstand lengthwise pull, from the other, general hitches. ABoK#1740 (and its small modification I made on it) is supposed to withstand lengthwise pull.
  Also try the "Buntline extinguisher", shown also at a attached picture
  Practical knots are seldom tied with/on elastic materials, and knot tyers do not have experience on them. I guess that many knots that are dismissed altogether as practical knots when tied with/on ropes and cords, will be OK with/on lengthwise elastic materials - and vice versa !
« Last Edit: February 28, 2012, 05:57:43 PM by xarax »
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Sweeney

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Re: New hitch?
« Reply #11 on: February 28, 2012, 10:35:39 AM »
Have you tried the Ossel Knot rather than the Ossel Hitch? The knot was used to attach the rope from the net to the floating headrope (the ossel hitch was at the net end under water) and therefore had to stand a lot of battering by the surface of the sea. It's pretty much a combination of groundline hitch and rolling hitch and seems to work in bungee cord but that has a textured surface.

Barry

xarax

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Re: New hitch?
« Reply #12 on: February 28, 2012, 11:59:40 AM »
... the Ossel Knot rather than the Ossel Hitch?

Could you, please, insert some pictures, so we can see the differences ?
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xarax

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Re: New hitch?
« Reply #14 on: February 28, 2012, 03:30:45 PM »
   Thank you SS369,

   I believe that the "Ossel knot" is a multi-wrap "Ossel hitch" - where the same mechanism is repeated two or even more times alongside the pole, is that correct ? 
« Last Edit: February 28, 2012, 04:29:47 PM by xarax »
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anything