Author Topic: Half turn hitches  (Read 6772 times)

ian

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Half turn hitches
« on: June 10, 2009, 10:07:06 PM »
I have been looking at hitches that have a half turn for attaching a halyard to a shackle, where there is not round for a full round turn.

My first thought was a bunting hitch but I have seen an "Intermediate" stopper knot (as Ashley calls it, ie between a figure of eight and a stevedore knot) with the shackle in the loop, if that makes sense.

A second thought is to use a bunting but to with a constriction knot instead of a clove hitch round the standing part. This is a very small change from a bunting hitch and produces a very secure hitch.

Any thoughts?

Ian

Dan_Lehman

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Re: Half turn hitches
« Reply #1 on: June 15, 2009, 04:00:41 AM »
"bunting" => "buntline"
"constriction" => "constrictor"

Ian, you can do well enough with the buntline hitch.
It might depend upon your particular materials; you say that there isn't
room ("round"=>"room) for a full round turn (as best naming goes,
you are making "a turn"), which suggests that the diameter of the
rope is equal or greater than that of the shackle!?

Since your refer to Ashley, I'll presume that you have (access to) ABOK.
A good noose-hitch to try vice the Buntline (which can be seen as one of
two ways of making a Clove noose-hitch) is tying #1821 around your line
after bringing it through the shackle; tie it so that the end is being tucked
down more towards the shackle than away.  (In the image Ashley provides
for #1821, the structure I'm recommending here would have the line
coming from the left, going clockwise through the shackle, and then
be tied off to itself as Ashley presents the line hitching to a ring.
One needs to ensure that the end is oriented just as Ashley shows,
not making it like a half-hitch  around its near part (which would
be something that could result from following leftmost image he
gives for #183, which he gives as a start to a larger knot).  In short,
one wants the line of this hitch to be drawing the end ever more
surely up against the noose's standing part (which I surmise will
give that part more *padding* and hence strength than for a
buntline hitch, where it will turn around the line directly, pull
against pull).  (This entire structure, sans noosed object, makes
what I call a "symmetric Figure 9" -- and is Ashley's #521

Another hitch to employ qua "noose-hitch" here is the Anchor
Bend / aka "Fisherman's Bend" -- #1840.  Draw it up tightly,
haul on the standing part of the noose-hitch and manually work
the knot snug to the shackle.  Here, too, I see less hard turning
of the line around itself.

Btw, do you want to be able to UNtie this line-to-shackle?
Because if you to, I recommend the latter knot above.  I just
gave both a quick stress test in some 8mm marine kernmantle
cord around 1cm carabiners, and I had to resort to trickery
to undo the former.
 ;D

---

Btw, substituting a Constrictor h. for the clove in the buntline (clove noose)
would likely be LESS secure.  And the Constrictor knot is not meant to be
loaded qua hitch -- i.e., from one end.

--dl*
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ian

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Re: Half turn hitches
« Reply #2 on: June 15, 2009, 08:19:49 AM »
Thanks for reply - and corrections and terminology.

It will take me some time to look at refs, as off sailing now, and I only have soft copy of ABOK.

Did you try the "intermediate eye-knot", for want of better name, that I described? I have tried it with polyester double braid and polished SS shackle and it does seem v secure. Also quick to tie and easy to undo. Although I can find no ref to it, it is reportedly in widespread use with yacht riggers in UK.

Ian

Dan_Lehman

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Re: Half turn hitches
« Reply #3 on: June 15, 2009, 09:36:52 PM »
Thanks for reply - and corrections and terminology.
Please understand that, although the particular corrections are pretty solidly that,
knot nomenclature is a quagmire of confusion, so references tend to be
confusing no matter -- take care in what you read/hear vis-a-vis that!

Quote
It will take me some time to look at refs, as off sailing now, and I only have soft copy of ABOK.
Argh, the Fisherman's/Anchor Bend should be known to a person off sailing!
Here's verbal light:  line goes around object fully and further (360 + 180 degrees),
to reach across standing part and then be tucked through the turn(s) just made.
(I write 'turn(s)' for although there's a sense of two, it actually can be really just
one that is fully manifest and bearing down upon the end, binding it against
the hitched object.)  To visualize:  if line begins by passing forward from you
over a rail, down around the backside and up around on the right of standing
part, over around back again, then now up and over top of the standing part
to be tucked now rightwards back against the rail under the "turn(s)".

And my suggestion is to use this knot vice the clove hitch in making what I
call a "noose hitch" . . .
 -- structure is noose-like in that ITS standing part
goes directly around hitched object, not participating in the tangle
of the knot but itself then being tied to with the knot of the structure
(the clove, or whatever)--
 . . . . . . . . . . . . . . . . and in the orientation that has the "turn(s)" going AWAY
from the noosed object.

Quote
Did you try the "intermediate eye-knot", for want of better name, that I described?
By following your description --which is perspicuous-- you are going one half-turn
beyond the Fig.8 and then making the tuck, and the "loop" of the knot is the standing
part's initial turn to form it, with the object being what it turns around (unlike in an
actual stopper where it would simply form a knob of material).  And if you think
about it, the knot I just described can be seen much like this, but in fact going the
full *distance* of the Stevedore BUT having the end tucked only into the PLANE of
the "loop" and then sharply turned to run through the coils/turns of the knot, not
completely through the loop plane.

Trying your hitch in somewhat aged, laid, 3/8" polypropylene, I find that the turns
of the knot grip enough on the noose's S.Part to be drawn a bit away from the
noosed object and thus to leave the "loop" area too OPEN and unnipping of the
end -- the knot would come untied.  This is a vulnerability aggravated by a relatively
larger-diameter object, mitigated by a smaller one and by slicker material (which
lessens the coil's grip and being pulled away).  One could tie off the end with an
Overhand stopper knot to prevent the spilling, and the effect can be to some
extent of having a friction hitch gripping the noose's S.Part, which should be
pretty strong; this overall structure though will be bulkier than some other solutions.

And that friction-hitch-like grip should server to KEEP the knot tight when the
line is slack, which is a plus.  It might be untiable by manually working the
coils over sideways, to pry loose the outermost turn, and thereby work some
of the line back through the coils and free the end.

Quote
I have tried it with polyester double braid and polished SS shackle and it does seem v secure.
Also quick to tie and easy to undo. Although I can find no ref to it, it is reportedly in widespread
use with yacht riggers in UK.

Thanks for the report from the field ("knots in the wild") !  Keep your eyes open,
no telling what you might see.

--dl*
====

TheTreeSpyder

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Re: Half turn hitches
« Reply #4 on: June 21, 2009, 03:32:45 PM »
Btw, substituting a Constrictor h. for the clove in the buntline (clove noose)
would likely be LESS secure.  And the Constrictor knot is not meant to be
loaded qua hitch -- i.e., from one end.

--dl*
====

this perplexes me, for i've used a slipped constrictor as firm end anchor point (to tree etc.) many times, and the BagKnot as same (slipped or knot).  How are the pulls so much different,that you could pull a Clove from 1 end, but not a Constrictor??  Is same said of Bag??

Dan_Lehman

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Re: Half turn hitches
« Reply #5 on: June 21, 2009, 06:35:22 PM »
Btw, substituting a Constrictor h. for the clove in the buntline (clove noose)
would likely be LESS secure.  And the Constrictor knot is not meant to be
loaded qua hitch -- i.e., from one end.
--dl*
====
this perplexes me,
Heck, that's one the things knots do best!   :D

Quote
for i've used a slipped constrictor as firm end anchor point (to tree etc.) many times, and the BagKnot as same (slipped or knot).  How are the pulls so much different,that you could pull a Clove from 1 end, but not a Constrictor??  Is same said of Bag??

In your case vs. the OP's, the object diameter is both relatively large AND frictive (rough),
so the mere turn of the rope 'round the object is going to bite and resist load.
So, one might ask How does making the Clove into a Constrictor help?
Now, the Bag knot I think you're referring to puts the tucked end in a position
that is locked more firmly, and cannot be dislodged, than with the Constrictor;
in that position it also enables prising out SPart material to loosen the knot,
so is a pretty ideal "spar hitch" -- #1674, of Ashley.

 :)


Inkanyezi

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Re: Half turn hitches
« Reply #6 on: July 05, 2009, 07:08:50 AM »
There is one knot that is better than most for attaching an anchor or for attaching the hook to a halyard, and that is ABoK #1843, a fairly unknown anchor hitch, which is fully secure even in slick spectra rope. Unlike any contraption built on the constrictor, it can rather easily be opened with a little patience and persuasion... It will never open by itself.

The knot is very simple, it's like the fisherman's bend with one more turn with the end through the first round turn. See http://web.comhem.se/~u77479609/anchor_bend.html

The knot has a few advantages over a splice, it does not make the line thicker or stiffer close to the end, and it provides positive bulk when it reaches the shiv.
« Last Edit: July 05, 2009, 09:52:25 PM by Inkanyezi »
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Sweeney

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Re: Half turn hitches
« Reply #7 on: July 05, 2009, 08:48:28 AM »
Geoffrey Budworth shows this in his "Encyclopaedia of Knots and Ropework" - it is indeed a very useful variant on the anchor (or fisherman's) bend.

Inkanyezi

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Re: Half turn hitches
« Reply #8 on: July 05, 2009, 10:09:57 PM »
Of course I missed a bit there on the original subject; the problem was that there was no room in the eye for a second turn. Then of course a buntline hitch or using a constrictor instead of half hitches around the standing part may make sense, but to my experience, much more can be passed through the eye of a snapshackle than one might think at first glance. But the limit of those eyes seems to be 10 mm rope if it shall pass twice.

Nevertheless, ABoK #1843 is my absolute favourite among those hitches. I often wondered about why people would add a half hitch to the fisherman's bend. The extra half hitch does not add a single bit of security to that knot. The second turn of #1843 however does.
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Dan_Lehman

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Re: Half turn hitches
« Reply #9 on: July 05, 2009, 10:52:14 PM »
... to my experience, much more can be passed through the eye of a snapshackle than one might think at first glance.
And if more than one diameter cannot be fit through, one might question
the appropriateness of the shackle to the line.

Quote
I often wondered about why people would add a half hitch to the fisherman's bend.
 The extra half hitch does not add a single bit of security to that knot.
Oh, but it does -- or can, depending upon material.  It can keep the knot from
loosening.  Moreover, that additional Half-hitch's added material to the knot could
be put in the form of an extra turn around the S.Part , much as the knot you
show, where the goal it to make a sort of friction grip of the S.Part to increase
slack-security (and strength?) -- something befitting flexible rope, as it is a turn
around 1 diameter.  Beyond this, there are other variations of putting in some
extra turn or tuck.  Beware the differences in hitching to a ring vs. spar.

--dl*
====

Inkanyezi

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Re: Half turn hitches
« Reply #10 on: July 06, 2009, 09:28:43 AM »
... I often wondered about why people would add a half hitch to the fisherman's bend.
 The extra half hitch does not add a single bit of security to that knot.
Oh, but it does -- or can, depending upon material.  It can keep the knot from
loosening. /.../

I beg to differ. The extra half hitch will not be nipped, ever.

The only condition under which a knot will hold, is that it provides nip, and a half hitch added around the standing part after the fisherman's bend will never have any pull on its own standing part that exits the fisherman's bend, hence will never have any nip provided to do any service at all. Of course I have tried these different knots under varying conditions to see what happens, and if you subject the most shown anchor bend, a fisherman's bend with an extra half hitch around the standing part, to repeated jerks, the extra half hitch will render first, regardless of material. Tie it in HMPE or tie it in bungee cord, it's the same. On the bungee, the jerks will undo the nip that might have been put into the half hitch, and once worked loose, it will open, but the fisherman's bend still holds.

So I stand by that. An extra half hitch around the standing part of a fisherman's bend is lore, but it does not add a single bit of security to the knot. Why else would it so often be shown with a seizing added to hold the end to the standing part? It's simple. People noticed that the half hitch they added came undone, so they added a seizing.
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Dan_Lehman

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Re: Half turn hitches
« Reply #11 on: July 06, 2009, 07:22:54 PM »
... I often wondered about why people would add a half hitch to the fisherman's bend.
 The extra half hitch does not add a single bit of security to that knot.
Oh, but it does -- or can, depending upon material.  It can keep the knot from
loosening. /.../

I beg to differ. The extra half hitch will not be nipped, ever.
The HH nips itself:  hauling on the end, to set it, brings the early part down
upon the end to nip the end.  Now, HHs make up a lot of knotting that one
finds eveywhere.  E.g., it is the basis for the "Reverse Groundline Hitch"
used in spiral bindings of netting, where the cord is wrapped around one
or more larger ropes until (sometimes immediately, in other cases widely
spaced) a HH is put in (which reverses the direction of the wrapping now),
and then a closing HH (reversing the reversal), and sometime this is repeated
one or more times, building up a sizeable binding hitch (but done in relatively
**flat** material so the bulk is more in breadth than thickness).

I'm taking your challenge seriously:  there is now a well tied and secure version
on the knot beside me, 7/16" manila(?) rope around a 10cm 'biner; the alleged
gratuitous HH looks snug and fine -- which took some added attention, giving
it a shove hitchwards after initial loading drew it away a little.

But I take you seriously for much cordage (and, i.p., I got no such security
in a bit of aged shock cord -- something more frictive than new).  This single
HH has to reach around a bit more span than it would in (Round Turn &) Two
Half-hitches (which I've seen slip in 8mm new kernmantle line around a 'biner).

But this HH can be put in so that it is tucked within the closing like structure
of the Anchor Bend (which is a sort of *buried* Half-hitch -- buried/tucked
under that initial turn around the ring).  And this variant is similar in security
to the double-tucked one discussed previously.

Quote
... but the fisherman's bend still holds.  .... Why else would it so often
 be shown with a seizing added to hold the end to the standing part?

Actually, this question can be turned against your assertion of holding:  why is
the knot almost always shown with some further security measure, usually a
seizing (even w/o the added HH) ?!  That is something I only recently came
to tell (and I'll not repeat my books search now, but did such a while back)!

The security of the Anchor/Fisherman's Bend is ever more suspect as the diameter
of the object increases relative to the cordage.  Note that the literature includes
essentially extensions of the Anchor Hitch such as Topsail /Stun Sail Halyard Bends
in which there is an extra turn and at least an extra tucking of the end.  I infer that
the basic hitch proved insecure over time, cyclical loading drawing out the end
unless the end made a u-turn into a 2nd tuck.  (Frankly, I think that a different
tuck than under the initial turn would be better, as it's that initial turn that can
become loose if any slack reaches the knot.)

--dl*
====

Inkanyezi

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Re: Half turn hitches
« Reply #12 on: July 11, 2009, 09:51:15 AM »
I've been revisiting this knot in order to find out its behaviour with different size objects to tie around, and I find the remarks by Dan quite valid.

The knot is not secure when the object has a much larger diameter than the rope. Usually there is not such a big difference in diameters when hitching to a ring, shackle or chain, but if you intend to use it for hanging a swing on a tree branch, you may easily exceed the limits of the knot.

However, if instead of making the two nipped turns forward, they are made by dogging the end around the previous turns backwards in timber hitch fashion, the knot becomes a more secure timber hitch, which is much easier to open than the anchor hitch #1843. The disadvantage, compared to the anchor hitch, is that there may be considerable chafe on the standing part where it exits the knot, as there is much more line that will elongate by the load, but this is due to the larger circumference of the object that it is hitched to, and might not be avoidable. Still, I prefer the somewhat more compact and in my opinion more good looking knot for attaching to a hook or snapshackle.

I don't know whether this knot has been recorded somewhere.
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Dan_Lehman

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Re: Half turn hitches
« Reply #13 on: July 11, 2009, 05:21:17 PM »
I've been revisiting this knot in order to find out its behaviour with different size
objects to tie around, and I find the remarks by Dan quite valid.
(Sometimes my thinking becomes less valid when I look more closely.  :(  )

Different materials should add to the issue -- some slick-hard PP (polyproplylene) rope
seems a good candidate for loosening, with its springiness.

Quote
The knot is not secure when the object has a much larger diameter than the rope.
There was an old (and reiterated) testing of some few common knots by
one of the major (then) rope makers, IIRC (presented by CLDay's Art of Knotting & Splicing
I think), which tested this bend to Two Half-Hitches (sans round turn, I believe)
on both small diameter and medium/large diameter objects:  the results were close
and this knot was the stronger on the larger dia. object.  I conjecture that this is
so because the loading pulls a bit of the tucked end out and then locks and with
some friction on the object maintains a angle to it more nearly tangential, which
is ideally strong; whereas the Two HH probably is slightly drawn off of the object
to more nearly the choker hitch angles and likely the S.Part of this effective
noose structure break where the HHs ever tightly bind around it.  Speculation, here,
but it seems to plausibly fit the results.  (Would that testers took efforts to make
better records -- threads sewn through rope to mark positions, and so on.)

Quote
However, if instead of making the two nipped turns forward,
 they are made by dogging the end around the previous turns backwards in timber hitch fashion,
 the knot becomes a more secure timber hitch, which is much easier to open than the anchor hitch #1843.
The ease of opening maybe is a disadvantage in terms of in-use movement &
loosening vs. #1843 if this latter will hold tension.  Depends on your needs ... ?

Quote
The disadvantage, compared to the anchor hitch, is that there may be considerable chafe on the standing part
where it exits the knot, as there is much more line that will elongate by the load, but this is due to the larger
circumference of the object that it is hitched to, and might not be avoidable.
Right:  it's the amount for the ojbect, not for the extra tuck.  And my comment
just above here is to this concern -- that maybe the #1843 can reduce how much
line goes back into the knot after its loaded!?

Now, what might a bona fide Timber Hitch do if given a round turn (or more)
as Ashley shows? (One might a round turn on the object and have dogging under
both wraps eventually.)  My thought is that the line won't so much be pulling
through this gripping coil but pulling it with it (and setting might be done with
a good load and manual pushing of the coil back towards the object); such a
grip on the line should be pretty strong!?

--dl*
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Inkanyezi

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Re: Half turn hitches
« Reply #14 on: July 18, 2009, 08:56:44 PM »
I couldn't resist trying some more variations, considering the problem of only one pass through the eye of the snapshackle. The buntline hitch is of course good enough, as well as a knot with a constrictor around the standing part, but I was looking for something simpler. Considering a simple half hitch would not be secure enough, I added a round turn under the half hitch, effectively making the Inside Clinch #1845, but without seizings. It is secure when tied in this way. The only negative thing to say about it is that it is quite a bit more difficult to untie than the anchor bend.

I have not yet tried it in slick material, but in ordinary polyester rope, it is quite convincing. Jerks will not make it slip.
« Last Edit: July 20, 2009, 08:54:19 PM by Inkanyezi »
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