Author Topic: Oxen bend (aka sliding cows bend) -- in HMPE  (Read 1430 times)

James Petersen

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Oxen bend (aka sliding cows bend) -- in HMPE
« on: January 13, 2015, 09:06:46 AM »
--EDIT--
Moderator, I see this might better have been posted as a reply in the sliding cows thread: http://igkt.net/sm/index.php?topic=4787.0 Please move it there if appropriate.
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Recently, thinking I was following a suggestion xarax, I did a few simple tests of a bend comprising two interlocked cow hitches, in 108 kg. test dyneema fishing line. That thread is here: http://igkt.net/sm/index.php?topic=4792.msg33910#msg33910

I was unimpressed with the knot, so I moved on to bull hitches.  I tested bull hitches with interlocked loops several times, which held well until failure, with occasional slippage (3/10 times iirc). Then I tested locked cow hitches with interlocked loops (interlocked, locked cow hitches  :o). These I tested 10 times in the same, 108 kg dyneema fishing line. In all these, the knot held to line failure with some occasional slight slippage. Something didn't seem quite right so, and after going back and looking again at the bend suggested by xarax, I finally realized in his bend, the hitches are made around the standing part/tail of the other line. Upon catching my error, I went back and tested with cow hitches around the standing part/working ends and the performance of this bend, in the line I used, was not simply impressive, but stellar. In all iterations, after initial tightening, the knot held until line failure with no perceptible slippage. I think that those who are looking for symmetric, reliable, end-to-end bends for UHMWPE/HMPE/Dyneema lines now have a worthy candidate which merits further investigations. I simply performed 10 pull-to-failure tests of this bend, so I have no data on its strength, or how easily it will untie in larger lines. These questions bear further study.

Xarax, I would like to suggest naming this bend the "oxen bend." In another thread, you said that when locked, the cow hitch becomes a bull. (http://igkt.net/sm/index.php?topic=4035.msg24785#msg24785) I would say that the cow hitches when used in this bend become more than "two cows", but are lacking that certain something needed to make them "bulls." -- Oxen ;D

Before testing these knots on this line, I also experimented with the EDK, which ran with ridiculous consistency. After about four iterations, I gave up on the simple EDK/overhand and tried one backed up by a second.  In three of 10 trials, the knots finally held to line failure after severe slippage. In the seven other instances, the knots ran out of line before the line ran out of strength.

--JP
« Last Edit: January 13, 2015, 02:58:35 PM by James Petersen »

xarax

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Re: Oxen bend (aka sliding cows bend) -- in HMPE
« Reply #1 on: January 14, 2015, 07:44:21 PM »
   As it happens in the Fisherman s knot, there are two ways those interpenetrating Cow or Bull hitches can be arranged. I think that the bends generated by the "less" symmetric way, although they are not face-symmetric ( they present different "front" and "back" views, because the two links are plane-symmetric, not point-symmetric ), they can nevertheless be inspected more easily than the bends generated by the "more" symmetric one.
  Following J.P. s idea, I had tried ( on "ordinary", only, material ) the "less" symmetric Oxen bends with interpenetrating Bull hitches - but also with Bull X hitches and with Bull Clove hitches. However, I am not sure that the additional riding turn over the one or two wraps ( at the "neck" of the more complex, more difficult to dress Bull X hitch and Bull Clove hitch ) is worth the trouble : it may not be able to increase any further the already present friction forces, which are generated in between the adjacent parallel turns when the two links are pushed towards each other.
« Last Edit: January 14, 2015, 07:46:22 PM by xarax »
This is not a knot.