Author Topic: Improving the humble cow hitch  (Read 18540 times)

knot4u

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Re: Improving the humble cow hitch
« Reply #15 on: December 06, 2010, 07:57:22 PM »
  Which knot do you call by the name "Slipped Bull hitch" and which "Bull hitch"? What is the part of the knot that is "slipped"?
  I thought that you were suggesting the name "left-handed" and "right handed" "Bull  hitch" for the two variations in the pictures of my original post.

I slipped both versions in your original post or both versions here:
http://books.google.com/books?id=GbeV0iKl8EgC&pg=PA120&lpg=PA120&dq=piwich+knot&source=bl&ots=ItGK6RAM3q&sig=KLg1jQv7cGjqjXMMFsezfAkVDUo&hl=en&ei=Mhb2TLXoDYLQsAOQz8CoCw&sa=X&oi=book_result&ct=result&resnum=5&ved=0CCgQ6AEwBA#v=onepage&q=piwich%20knot&f=false

The slip involves nipping a bight at the final exit of the working end.  It's the most obvious way to slip it.  Don't over think it.

Dan_Lehman

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Re: Improving the humble cow hitch
« Reply #16 on: December 06, 2010, 08:01:26 PM »
I tie the Cow specifically because the Cow has NO hold when there is no load.

The Cow hitch has ample hold in many materials qua ring hitch,
where it improves on the Clove hitch in being easier to loosen & untie.

Quote
To address jamming issues, I tested a Slipped Bull.  On the positive side, the Slipped Bull (each variation) works well to address jamming issues, ...

Your testing is insufficient (and you gave few specifics).
Repeating the quick-test I did with quarter-inch laid CoEx-PP/PE
I find the jammed slipped distal** Bull hitch damn-jammed.
Getting the round-turn collar to slip over the 3 diameters of the
knot is maybe harder than doing so for just the 2 dia. of the
unslipped version --the trio of strands making the ideal circular
grouping of material to be compressed & nipped without need
of as much bending of the encircling wraps.
-- I'll have to "cheat" and take this hitch off of the 'biner
by sliding it, then untying it!   ouch!

[** "distal" in a quick "away" denotation in reference to the
Bull H.'s nipping coil-collar; "proximal" would be the other loading.]

NB:  It is bad to refer simply to "the Bull hitch" without further indication
of the particular loading, as behavior depends upon that.

--dl*
====

alpineer

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Re: Improving the humble cow hitch
« Reply #17 on: December 06, 2010, 08:37:02 PM »
I dedicate this knot to xarax. I call it the PILE O' BULL HITCH! ;D

knot4u

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Re: Improving the humble cow hitch
« Reply #18 on: December 06, 2010, 09:37:57 PM »
Your testing is insufficient (and you gave few specifics).
Repeating the quick-test I did with quarter-inch laid CoEx-PP/PE
I find the jammed slipped distal** Bull hitch damn-jammed.
Getting the round-turn collar to slip over the 3 diameters of the
knot is maybe harder than doing so for just the 2 dia. of the
unslipped version --the trio of strands making the ideal circular
grouping of material to be compressed & nipped without need
of as much bending of the encircling wraps.
-- I'll have to "cheat" and take this hitch off of the 'biner
by sliding it, then untying it!   ouch!

[** "distal" in a quick "away" denotation in reference to the
Bull H.'s nipping coil-collar; "proximal" would be the other loading.]

NB:  It is bad to refer simply to "the Bull hitch" without further indication
of the particular loading, as behavior depends upon that.

--dl*
====

Basically, the performance of the Slipped Bull in your testing is even worse than what I found.  How you managed to jam a Slipped Bull Hitch, I don't know, but I'll take your word for it that you could.

By the way, I indicated above that I tested both variations from the original post.  I tested that cheap rope from Home Depot.  I also tested boot laces.  I used various different object shapes and sizes.  The performance was too poor to get me motivated to write too many more details here.
« Last Edit: December 06, 2010, 10:52:13 PM by knot4u »

Dan_Lehman

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Re: Improving the humble cow hitch
« Reply #19 on: December 07, 2010, 12:46:27 AM »
Basically, the performance of the Slipped Bull in your testing is even worse than what I found.  How you managed to jam a Slipped Bull Hitch, I don't know, but I'll take your word for it that you could.

?!  It jams just as any other knot would.  If you can liberate
this knot by pulling out a slip-bight --i.e., getting a strand to
move through the round-turn nip--, then you could loosen
the knot by moving the round turn back on the SPart/tail
and readily break the knot.  As I said, having the 3rd strand
to surround might even add to the tightness as its a little
easier for the turn to flow and increase tension around 3 strands.

Quote
By the way, I indicated above that I tested both variations from the original post.  I tested that cheap rope from Home Depot.  I also tested boot laces.  I used various different object shapes and sizes.  The performance was too poor to get me motivated to write too many more details here.

Yes, both versions, you said, re the slipped knot.  Now, if
you got jammed rope with the "proximal" (XaraX's righthand in OP)
version (unslipped or otherwise), that's hard to figure!  With boot
laces (flat, round, ...?) you can give pretty high relative force rather
easily; with the Home Depot (3/8" ?) kermantle, no so easily.
I used a pulley (5:1 but hardly in great working order) and body
wgt (180#) w/some bounces --and that's a serious load; should
be well more than my rope's WLL, for that matter.

 - - - - - - -

One could revise the knot with the following variation:

  make a full (round) turn and then flow into the round-turn
  collar ; finish as usual.  (not sure what Alpineer's done--maybe this)

The tail has the collar-tightening advantage and so the knot
can be set pretty tight ; the SPart is impeded from making
the knot overly tight by both the version choice (the "proximal"
version --SPart wrapping into collar away from object--,
and the extra turn around the object further impeding delivery
of force into the nipping collar.

It should be remarked that we here might have all been hitching
to a smooth object (e.g., I to a 'biner, as a ring hitch); but the
transmission of force around a rough object (tree limb, say) is
far less, and the jamming (even setting tight) harder to get.


--dl*
====

knot4u

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Re: Improving the humble cow hitch
« Reply #20 on: December 07, 2010, 12:57:38 AM »
?!  It jams just as any other knot would.  If you can liberate
this knot by pulling out a slip-bight --i.e., getting a strand to
move through the round-turn nip--, then you could loosen
the knot by moving the round turn back on the SPart/tail
and readily break the knot.

???

I don't see how the part after the word "then" logically follows what comes before it.

If a Bull Hitch is jammed (whichever variation), then it's difficult to "loosen the knot by moving the round turn back on the SPart/tail and readily break the knot".  However, a Slipped Bull Hitch (whichever variation) comes loose relatively easily with a firm yank of the working end.  The slip option is there for someone who wants to ensure the knot will be easy to untie.
« Last Edit: December 07, 2010, 01:26:10 AM by knot4u »

knot4u

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Re: Improving the humble cow hitch
« Reply #21 on: December 07, 2010, 01:52:12 AM »
The Cow hitch has ample hold in many materials qua ring hitch,
where it improves on the Clove hitch in being easier to loosen & untie.

I agree that the Cow Hitch has ample hold when there is loading.  Without loading, the Cow Hitch has essentially no hold.  In other words, the internal forces of the knot are not doing much to keep the knot pressed tightly against the object.  Again, I view that as a feature, not a flaw.

Dan_Lehman

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Re: Improving the humble cow hitch
« Reply #22 on: December 07, 2010, 04:33:27 AM »
... The slip option is there for someone who wants to ensure the knot will be easy to untie.

This is specious, as I showed : in a truly jammed knot, there is
no effective "slip option" --nothing moves.  (And even if by some
force multiplier (capstan, winch) to assist, in many ropes there
will be at least some *snow-plowing* effect AND a bulge of a
folded slip-bight tip that will not pull out.)

.:.  With the Bull Hitch variations (of which only the "distal" one
is much a jam threat, I think), if one can move a strand within
the collar's nip, then one should be able to move a half-turn
of the collar and continue such working to break the knot
--it is movement of whichever, relative to the other : strand
to collar or vice versa (jamming denying both).

--dl*
====

knot4u

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Re: Improving the humble cow hitch
« Reply #23 on: December 07, 2010, 04:51:25 AM »
This is specious, as I showed : in a truly jammed knot, there is
no effective "slip option" --nothing moves.

???

I have jammed a Buntline where a Slipped Buntline would not be jammed.  I consider a knot to be jammed if I can't work it loose after a reasonable amount of time.  A slip provides a leverage that is otherwise non-existent without the slip.

Anyway, I don't even know why I'm arguing with you.  A Slipped Bull Hitch was clearly easier to untie to a regular Bull Hitch in some testing I did, and the other characteristics of the knot did not appear to change.
« Last Edit: December 07, 2010, 05:13:53 AM by knot4u »

Dan_Lehman

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Re: Improving the humble cow hitch
« Reply #24 on: December 07, 2010, 05:10:59 AM »
I dedicate this knot to xarax. I call it the PILE O' BULL HITCH! ;D

Hot dang, good show!  We could use some new old blood here,
even with purple rope.

Now, what's the point of this Pile o' Bull?  --looks to me as though
it could do with more turning, to become adequately secure when slack.

You are aware that rockclimbers might have a use for the Bull Hitch,
or what they might prefer to call "an Improved Girth Hitch" --using
it to keep in place a typically tape sling/runner on a chickenhead
or extending piton (huh?  who uses such things, you say!).  For
the former --i.e., on a relatively large-diameter object--, it might
be better to replace the Bull's round turn with a Clove Hitch (i.e.,
the loaded parts are drawn through a nipping Clove Hitch).

Which reminds me that I was just fiddling around with a structure
derived from a slip-knot/-noose for such a purpose.

--dl*
====

Dan_Lehman

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Re: Improving the humble cow hitch
« Reply #25 on: December 07, 2010, 05:59:11 AM »
This is specious, as I showed : in a truly jammed knot, there is
no effective "slip option" --nothing moves.

???

[transient version 1 :-]
That statement is untrue in my world.  I can tie a Buntline that will be considered jam by people who don't have special powers.  I can then tie a Slipped Buntline right next to it in the same conditions, just slipped.  I would be able to untie the Slipped Buntline relatively quickly.  A slip provides a leverage that is otherwise non-existent without the slip.  In contrast, the jammed Buntline would have to be cut after I wrestle with it for five minutes only to make it tighter and tighter.

[version 2]
I have jammed a Buntline where a Slipped Buntline would not be jammed.  I consider a knot to be jammed if I can't work it loose after a reasonable amount of time.  A slip provides a leverage that is otherwise non-existent without the slip.

Anyway, I don't even know why I'm arguing with you.  A Slipped Bull Hitch was clearly easier to untie to a regular Bull Hitch in some testing I did, and the other characteristics of the knot did not appear to change.


I was hoping we wouldn't have to consider the peculiarities of other worlds
or conjecture myself special powers.  But you do come up with some strange
observations and so I must wonder ... .  As told, I did the quick testing that
I reported, with the serious pulley-generated forces which amount to hundreds
of pounds.

Now, I had at one point (in a too transient text) put in some
allowance for exceptions re my assertion about slipping's merits
being specious, and then trying to focus on the OP's knots as
heeding the rule, but that ... well, was transient indeed.  Still,
I might grant that some "YMMV" applies depending upon the
knot structure, where the slip-bight might come under less
stricture but the usual points of breaking the knot be jammed.

And I thought that you might've landed one right away, with
the Buntline, and so I have now given that some quick testing
too --same materials : the quarter-inch CoEx laid rope and 3/8"
(multifilament PP?) "Home Depot" rope (I found it, so can't
speak w/assurance re its origins --but it fits the description).
The former is more frictive than the latter, which yet has some
*new* feel & slickness.  .:.  In both cases, I was able to break
the Buntlines by pushing the outer turn w/thumb, working on
the away-from-SPart side of the turn in the CoEx case, which
was the more tightly jammed.  (force?  well, the 'biners were
locked from stretch --I think they are supposed to be able to
be opened at at least 200#, by UIAA standards?  --Alpineer?)
And in both cases, pulling the slip-bight tail was not very
helpful --harder (& futile?) w/CoEx; likely problematic in
the harder-loaded, 2nd time, with Home Depot, at the
point of the final bulge coming to the knot (the very bight-end
bulking, w/torque, to boot).  Still, I'll allow that perhaps in
some stretchy Nylon under suitable load the material extension
could lead to a tight nip of the diminished-diameter SPart
such that on relaxation the SPart could not feed back into
the knot, and the tight nip would be considered jammed,
and yet the tightness upon the slip-bight might not be
so great as to preclude its coming undone.  That sure
wasn't the case for my two ropes around a 'biner, ring
hitches.

And I'll reiterate that there was NO MOVEMENT in the case
of the jammed Bull Hitch (distal).

Now, if in your world you're playing with tiny stuff such
as boot laces, you will have (1) much more difficulty in
getting the sort of *push* purchase because of such great
disparity between your digit size & material diameter; AND
(2) you'll have "Paul Bunyan" strength advantage for pulling
a slip-bight out.  (Though we should remark that for the Bull
Hitch the slip-bight's tail isn't well oriented to be pulled, as
it points back at the hitched object; one might hold the SPart
and pull ... , but that's awkwards.)  But I should hope that
you (and if not, at least others) will come to see that your
belief that one can adequately test knots by using small
stuff and then project that behavior more broadly is highly
dubious.


--dl*
====

knot4u

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Re: Improving the humble cow hitch
« Reply #26 on: December 07, 2010, 06:15:18 AM »
This issue is not that complicated and unworthy of this much attention.  Bottom line, I'll still be using a slip in my Buntlines and many other knots because they otherwise jam on me.

Dan_Lehman

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Re: Improving the humble cow hitch
« Reply #27 on: December 09, 2010, 07:35:25 AM »
This issue is not that complicated and unworthy of this much attention.  Bottom line, I'll still be using a slip in my Buntlines and many other knots because they otherwise jam on me.

Complexity is not at all what is at issue here,
but observation/testing and reporting,
which certainly IS worthy of attention for it's what
knotting has been lacking for so long.  And so it is quite
a curious thing to see such conflicting reports of behavior.

And I should not be the only one checking these claims
of jamming or superior strength or whatever.  But at least
I have been checking.

--dl*
====

xarax

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Re: Improving the humble cow hitch
« Reply #28 on: February 24, 2012, 03:32:04 PM »
   If we use more coils, we can pre-tighten the two standing ends of the improved Cow hitch / Bull hitch, and this pre-tightening will able the coils to remain perpendicular to the axis of the pole, be squeezed between their neighbour coils, and grip it very tightly, even during a lengthwise pull. ( See the attached pictures, and read the posts at (1), and all the other posts there, describing the "pre-tensioning" / pre-stressing effect. ).
   The long, double X "neck" will nip the two standing ends sufficiently, and retain this blockage even when the standing ends are not pulled any more. So, the standing parts will not be allowed to slip though it, and release their tension, and the enhanced friction of the coils with the surface of the pole.

1. http://igkt.net/sm/index.php?topic=3794.msg22221#msg22221
This is not a knot.

SS369

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Re: Improving the humble cow hitch
« Reply #29 on: February 24, 2012, 03:48:48 PM »
Very good xarax!

This is and has been my preferred knot on my Purcell prusik. It makes the foot loop so much easier to use. It stays in shape throughout all the gyrations of ascending.

SS