International Guild of Knot Tyers Forum

General => Practical Knots => Topic started by: knot4u on June 29, 2010, 03:14:57 AM

Title: Best Gripping Hitch for Vertical Pole
Post by: knot4u on June 29, 2010, 03:14:57 AM
The application is a slick vertical pole.  What's the best hitch?

I tested the good old Klemheist option on a vertical pole.  It performs quite well, and possibly the best of all knots I've tested so far.  However, as far as I know, there is no practical way to tie this option if there is a load already on the standing end.  The standing end must be passed through the end loop once you wrap the loop around the pole.

EDIT: After testing many hitches, the hitches below are some of my favorites.

Well Pipe (ABOK #504)
(http://i55.tinypic.com/330g0id.jpg)
http://www.oktroop17.org/knots/Pipe_Hitch.html


Klemheist (ABOK #1762)
(http://i52.tinypic.com/20gzl2c.jpg)
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: jcsampson on June 29, 2010, 03:34:19 AM
Why, the "Four-Coil-Ring Fixed-Gripper Coil Hitch," of course!

- http://igkt.net/sm/index.php?topic=1839.msg12495#msg12495

If it doesn't knock your socks off, then you didn't make it right.

JCS
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: dmacdd on June 29, 2010, 01:20:22 PM
The application is a slick vertical pole.  What's the best hitch?


Absent other requirements, and assuming the load is parallel to the pole, why would the simplest not be the best? I offer a coil wound tightly around the pole away from the load, finished with two half hitches around the SP, snugged up against the coil.  I forget the ABOK number for this, but do remember that Ashley calls it the well pipe hitch.

Alternatively, http://davidmdelaney.com/icicle-hitch/icicle-hitch.html (http://davidmdelaney.com/icicle-hitch/icicle-hitch.html)
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: roo on June 29, 2010, 02:50:51 PM
The application is a slick vertical pole.  What's the best hitch?
The number of tests required with different materials, conditions (wet?), pole diameters, rope diameters, loading profiles, taper shape, mood of the tester, etc., makes this a nebulous and hard to address question.  My experience is that that difference in most of these dime-a-dozen hitches is not all that great, especially if you throw enough rope at the problem.  Just pick one that doesn't unwind on you and is easy for you to execute.

By the way, it's "Gripping Sailor's Hitch", not "Sailor's Gripping Hitch".   It's a gripping version of the Sailor's Hitch, not a Sailor's version of a non-existent Gripping Hitch.

Title: Re: Best Gripping Hitch for Vertical Pole
Post by: roo on June 29, 2010, 04:43:18 PM
By the way, it's "Gripping Sailor's Hitch", not "Sailor's Gripping Hitch".   It's a gripping version of the Sailor's Hitch, not a Sailor's version of a non-existent Gripping Hitch.

OK, but many folks on the Internet refer to the knot as the Sailor's Gripping Hitch, for example:

http://www.layhands.com/Knots/Knots_Hitches.htm
http://igkt.net/sm/index.php?topic=1158.0
http://www.skytopia.com/project/articles/knot/knots.html
http://www.survivalworld.com/knots/index.html
http://en.wikipedia.org/wiki/Gripping_sailor%27s_hitch (The Title)

For identification purposes to those references, I'll refer to the knot as the Sailor's Gripping Hitch.
Yes, and they're all wrong.  I should know;  the name originated on the Notable Knot Index.

The only question is who first mis-typed the name. :D
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: roo on June 29, 2010, 05:05:59 PM
So, you invented/formalized the knot? 
The particular Gripping Sailor's Hitch?  Yes. 
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: DaveRoot on June 29, 2010, 06:21:13 PM
A few years ago I was asked to add the "Sailor's Gripping Hitch" to my Hitches page at http://www.layhands.com/Knots/Knots_Hitches.htm (http://www.layhands.com/Knots/Knots_Hitches.htm), based on another website which referred to it as the "Sailor's Gripping Hitch."

But if "Gripping Sailor's Hitch" is the original name then I'll be happy to change my website to make it more accurate.

Dave

Title: Re: Best Gripping Hitch for Vertical Pole
Post by: jcsampson on June 29, 2010, 10:23:43 PM
Quote from: dmacdd
"I . . . remember that Ashley calls it the well pipe hitch."

The "Well-Pipe Hitch" is ABOK #504. You'll find that having more than four coil rings is unnecessary and can sometimes be problematic. Two Half Hitches will get the job done, but it is amazing how a Fixed-Gripper Knot instead of Two Half Hitches (or the Buntline Hitch knot) can noticeably improve the performance of the construct. A Fixed-Gripper Knot can be made tight, be pushed flush into the coil, stay put, actually aid the grip itself, and do the job noticeably better than either Two Half Hitches or (the component knot of) the Buntline Hitch.

ABOK #505 looks like a great construct, too. Of course, the main problem is that it will likely drop as soon as the connection to it (e.g., the hook) stops pulling, but whether this matters depends upon the application. Its quickness in making and removing could be the very thing needed for an application, so ABOK #505 gets my vote as another satisfying option. ABOK #505 reminds me of the Klemheist, but the Klemheist will sometimes (depending upon the position of the standing part) fail to have an adequate pull on both sides of the coil, which I feel is the main reason why many hitches grip poorly, whether temporarily.

JCS
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: jcsampson on June 29, 2010, 10:30:59 PM
If the gripping performance, on a vertical pole, of the "Four-Coil-Ring Fixed-Gripper Coil Hitch," which I mentioned earlier in this thread, virtually knocked your socks off, then what I am about to mention may downright knock you off your feet:

Try making another Four-Coil-Ring Fixed-Gripper Coil Hitch on a vertical pole, but instead of using the component knot of the Fixed-Gripper Hitch (namely, the Fixed-Gripper Knot) to make your coil hitch, use the slide-and-grip structure of the Fixed-Gripper Slide-and-Grip Hitch. Take your time, dress it well, and push it well into the four-coil-ring coil a number of times, until all of the play has been completely worked out of the structure and it is as flush as possible to the coil on the pole.

Finally, try the slide-and-grip structure of the Fixed-Gripper Slide-and-Grip Hitch Variation to make your Four-Coil-Ring Coil Hitch.

- http://igkt.net/sm/index.php?topic=1839.msg12539#msg12539

Disclaimer: I am not responsible if you hit your head when the gripping performance of this structure knocks you off your feet.

JCS
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: Erickson on July 07, 2010, 07:46:06 AM
Well obviously the "Best" hitch is the McLoughlin Hitch  ;D http://igkt.net/sm/index.php?topic=1764.0

But really, I'd go with an icicle hitch. I've been playing with the Mason Hitch just now and I like the finish on it, one thing I don't like about the Gripping Sailor's Hitch. Actually I think Roo's right,
Quote
My experience is that that difference in most of these dime-a-dozen hitches is not all that great, especially if you throw enough rope at the problem.
Which the Four-Coil-Ring Coil Hitch manages nicely, grippy though it may be.

K-
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: dmacdd on July 23, 2010, 01:48:32 AM
I'm liking the following:

Mason Hitch (my favorite)
http://plotus.dreamhosters.com/MasonHitch.jpg

I tied the Mason Hitch and finished it off tight with a slipped half hitch.  It works quite well, and this knot combination is now on my favorites list.

Hmm.. The Mason hitch as drawn above seems to me to be likely to be less secure than the unnamed hitch at http://davidmdelaney.com/icicle-hitch/icicle-hitch.html, because of the apparently superior way that, in the latter, the SP nips the WE against itself and the pole. It seems to me that the Mason hitch could have the same property simply by insuring (drawing) the WE closer to the pole than the SP in the loop that nips the SP and the WE, contrary to the way the cited drawing shows it.
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: Bob Thrun on July 23, 2010, 10:36:37 PM
The application is a slick vertical pole.  What's the best hitch?

I'm liking the following:

Mason Hitch (my favorite)
http://plotus.dreamhosters.com/MasonHitch.jpg
That would be called a Distel Hitch by arborists.
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: Dan_Lehman on July 23, 2010, 11:32:03 PM
Mason Hitch (my favorite)
http://plotus.dreamhosters.com/MasonHitch.jpg
That would be called a Distel Hitch by arborists.

???  By which arborists?  -- not Mahk Adams, nor do any of the readily
accessible images match this.  As put verbally, the Distel "is like a 3:1
Clove -- AND both ends are loaded.  In this "Mason", it is not a Clove,
and only one end is loaded, with an interesting nip of the end
-- like a Reversed Ossel Hitch.

 :)
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: DerekSmith on July 24, 2010, 01:46:39 PM
The application is a slick vertical pole.  What's the best hitch?
...snip

'best' has numerous aspects, but for ease of tying and excellence of grip I would use the KC hitch http://igkt.net/sm/index.php?topic=542.0 (http://igkt.net/sm/index.php?topic=542.0)

(http://igkt.pbwiki.com/f/KC%20Hitch07%20sml.jpg)

or the Beefed up KC Hitch http://igkt.net/sm/index.php?topic=551.0 (http://igkt.net/sm/index.php?topic=551.0)

(http://igkt.pbwiki.com/f/double%20KC%20sml.jpg)


Remember though, that all these hitches only work well when the cord diameter is significantly smaller than the pole.

Derek
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: knot4u on July 27, 2010, 01:40:28 AM
Remember though, that all these hitches only work well when the cord diameter is significantly smaller than the pole.
Derek

Those hitches in your pics have overlapping loops on the main grip around the pole.  For vertical pole applications, I have found overlapping loops to reduce the grip to the pole in the vertical direction (aka, lengthwise direction).  I suspect that's why most established hitches for lengthwise pull do not have overlapping loops at the main grip around the pole.
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: dmacdd on July 27, 2010, 01:51:28 AM
The Camel Hitch tied for a vertical pole is my new favorite.  Here is the loosened hitch:

It's not the knot that ABok 1741 calls the camel hitch.   That camel hitch has the lower hitches going the other way around the pole, similar to the (unhitched)
http://davidmdelaney.com/icicle-hitch/icicle-hitch.html (http://davidmdelaney.com/icicle-hitch/icicle-hitch.html)


Title: Re: Best Gripping Hitch for Vertical Pole
Post by: dmacdd on July 27, 2010, 04:00:23 AM
OK, is there a common name for the hitch in my pic?

I don't know.  But it's a rolling hitch with two extra turns and one extra hitch.
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: Dan_Lehman on July 27, 2010, 05:10:14 AM
The Camel Hitch tied for a vertical pole is my new favorite.  Here is the loosened hitch:

It's not the knot that ABok 1741 calls the camel hitch.   That camel hitch has the lower hitches going the other way around the pole, ...

OK, is there a common name for the hitch in my pic?

Brion Toss's Rigger's Apprentice has as the Camel Hitch your version, but
with fewer turns -- apparently he didn't notice the difference w/Ashley's.

Note that Ashley shows it pulled the opposite way but notes that
the intent is to hold in either direction; Toss seems to presume just
the opposite-way loading, and shows it as the knot of a noose-hitch.


Frankly, I'd dispense with the final Half-hitch (making the Clove) and
tie off with an Overhand stopper not instead -- MUCH more secure!

Or, finish the knot (at the point of this Clove hitch) with a Reverse Cow
hitch
-- i.e., turn the tail in the opposite direction,
come back around on the away side from the knot (making no Half-hitch),
and then turn around your tail and go around to bring the tail
out through this turn so that the turn/bight nips it against the
lead into this "Reverse Cow" finish.  The nipping is sure, and even
increased by loading the structure's SPart in the direction you show.

(To put this in other words, in this Cow finish, the tail will reach
to the away side of it and finish on the near side; were you putting
oh Half-hitches in the usual way, it would go near to away.  The
loaded part of this "Reverse Cow' will pinch the tail against the turn.)


--dl*
====
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: Bob Thrun on July 27, 2010, 05:32:03 AM

???  By which arborists?  -- not Mahk Adams, nor do any of the readily
accessible images match this.  As put verbally, the Distel "is like a 3:1
Clove -- AND both ends are loaded.  In this "Mason", it is not a Clove,
and only one end is loaded, with an interesting nip of the end
-- like a Reversed Ossel Hitch.

 :)

You are right.  It was not clear in the original drawing that only one end was loaded.  And I missed the way the final tick is done.
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: Dan_Lehman on July 27, 2010, 05:35:14 PM
Nice image!   :)   Yes, that's it (simply described (simply altered one way or another)).
And I think that --esp. for tying to a pole, in contrast to some flexible object--
this structure is less secure under load --to it I'd finish with a stopper,
if not replacing the final Half-hitch with a stopper as said above.
(I don't trust the Clove h. to stay tied.)

Friction hitches can be tricky, and I have some skepticism about them,
in general.  So much seems to depend on materials (structure, fibre,
condition, shape, flexibility, relative sizes) and forces.  I recall using
a Hedden hitch in (I think) half-inch solid/flexible polyester (lubed!)
cable-hauling tape in which it held my weight initially, but on subsequent
attempts to stand on this it slid (!!?).  And recently in playing around
with the ProhGrip / Blake's Hitch, I found that I needed to slightly
extend the spiral of the rope coming into the knot in order for
it to grip and then grip harder w/higher load.  That said, I'll remark
that it seems a piece of common knowledge that with standard
materials of an 8mm? kernmantle rope tied in a Prusik hitch around
11-13mm kernmantle  slippage will occur at some high load.  (It's
of course possible that this "knowledge" arises from one reported
testing.  And in some cases of such testing where slippage is seen,
the testing is done on a slow-pull device that takes a while to build
up force on the slipped knot, but with actual use and some mass
making that load, there'd be no such reduction in force upon the
slippage --rather, some momentum of the load.)

Also, there isn't much presentation and research made for using some
combination of friction hitches -- e.g., a structure like what is
called the "Camel hitch" but in place of the Clove hitch there is
a Rolling hitch (or other friction hitch) and the load of course is
taken in the usual direction (for what I'll call "away-end" loading
-- that of the Rolling h., e.g.).  As shown in the OP, the loading
is to the "near-end" , as is the Klemheist & ProhGrip.


--dl*
====
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: knot4u on July 27, 2010, 07:20:35 PM
Frankly, I'd dispense with the final Half-hitch (making the Clove) and
tie off with an Overhand stopper not instead -- MUCH more secure!

Or, finish the knot (at the point of this Clove hitch) with a Reverse Cow
hitch
-- i.e., turn the tail in the opposite direction,
come back around on the away side from the knot (making no Half-hitch),
and then turn around your tail and go around to bring the tail
out through this turn so that the turn/bight nips it against the
lead into this "Reverse Cow" finish.  The nipping is sure, and even
increased by loading the structure's SPart in the direction you show.

EDIT:  The pic below is a hitch with the Overhand Stopper finish.  I took the liberty of naming them.  Yes, this hitch is quite secure. To prevent jamming and to make the overhand a little bigger, add a slip on the overhand.  For simplicity, there is no slip shown.

"Gripping Half Hitch"
(http://i27.tinypic.com/2912ayw.jpg)
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: dmacdd on July 27, 2010, 11:28:18 PM

Or, finish the knot (at the point of this Clove hitch) with a Reverse Cow
hitch
-- i.e., turn the tail in the opposite direction,
come back around on the away side from the knot (making no Half-hitch),
and then turn around your tail and go around to bring the tail
out through this turn so that the turn/bight nips it against the
lead into this "Reverse Cow" finish.  The nipping is sure, and even
increased by loading the structure's SPart in the direction you show.

I cannot follow this. I presume it is not this:
(http://davidmdelaney.com/icicle-hitch/icicle-hitch-step-4.gif)
which would, I presume, be said in this context to be finished with an unreversed cow hitch.
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: DerekSmith on July 28, 2010, 09:23:11 AM
Remember though, that all these hitches only work well when the cord diameter is significantly smaller than the pole.
Derek

Those hitches in your pics have overlapping loops on the main grip around the pole.  For vertical pole applications, I have found overlapping loops to reduce the grip to the pole in the vertical direction (aka, lengthwise direction).  I suspect that's why most established hitches for lengthwise pull do not have overlapping loops at the main grip around the pole.

Hi K4u,

Interesting observation, but a strange one - the inclination of the pole should have no impact whatsoever on the forces present in the knot under load, in fact the KC Hitch works perfectly in any orientation.

(http://knotbox.pbworks.com/f/KC%20Hitch07%20vert%20sml.jpg)

The example shown is 3mm polyester braid tied onto a bright chrome pole.  You will notice that under load, the first loop has opened to about 40 degrees and the second has opened to about 10 degrees while the anchor loops have not opened at all.  Load tension causes the first loop to slide along the pole, increasing the angle and so forcing an extension in the cord.  This extension builds significant tension in the cord which increases the grip between the cord and the pole - the greater the load, the more the knot opens and so the feeble friction between the cord and the chrome is increased until the load is met.  If opening the first loop is not sufficient to create ten necessary tension / grip, then the second loop starts to open and on very slippery surfaces, even the third loop may be required to open to generate the required tension / grip.

Sufficient turns should be used so that the last two wraps are not affected when the load is applied - this is the 'root' or 'anchor' of the knot and must be free from any directly applied lateral forces which must all be taken by the expanding loops.  You will see that this is the principle difference between the KC which keeps all 'lengthwise' tension away from the root, while others all take a line to the back of the knot and thereby tend to disrupt the stability of the whole knot.

Derek

Give it a try.

Derek
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: knot4u on July 28, 2010, 04:34:45 PM
Those hitches in your pics have overlapping loops on the main grip around the pole.  For vertical pole applications, I have found overlapping loops to reduce the grip to the pole in the vertical direction (aka, lengthwise direction).  I suspect that's why most established hitches for lengthwise pull do not have overlapping loops at the main grip around the pole.

I made no comment about the inclination/orientation of the pole in your pics.  By the way, I say "vertical pole" in the original post just so it's clear that we're talking about lengthwise loads.

To clarify, in the knots of your pics, the multiple wraps around the pole overlap each other.  That's unlike almost all other established gripping hitches.  For example, these other gripping hitches have multiple wraps that do not overlap:  Klemheist, Prusik, Gripping Sailor, Isicle, Distel, Mason, Adjustable Grip, Tautline, Camel, Gripping Clove (pic above), Gripping Half (pic above), Gripping Clove (pice above) and some other gripping hitches.

The overlaps take away some friction from the pole (where the friction should be) and apply that friction to the overlapped portion of the rope.  Further, where wraps do NOT overlap in those other gripping hitches I mentioned above, the load applied to the multiple wraps is transferred throughout the multiple wraps, and the friction to the pole therefore increases.  In your knots, because of the overlaps, that extra bit of friction is non-existent.

By the way, I took the time to test your hitches with various ropes and various poles.  So, even if my theory explanation above is inaccurate, the bottom line is that I have found other gripping hitches to perform better for the application in the original post.  I encourage everybody to test all the hitches in this thread.  It's fun.  Also, I came into this thread thinking that a gripping hitch could not get better than the Mason or the Gripping Sailor's.  However, I now have new favorites, and I'm still looking for improvements.  :)
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: Dan_Lehman on July 28, 2010, 04:53:45 PM

I cannot follow this. I presume it is not this:


I'm pretty sure it's the hitch in the pic above that I call "Gripping Cow Hitch".  Dressed tightly, the hitch is quite secure.  :)

HALF-BINGO!  -- nice to see words interpreted pretty correctly.
"Gripping Cow" doesn't fit, though:  the gripping part is if anything
*Cloved*, just looking at how the tail proceeds, but in this case I don't
think it will much matter; the *Cow* aspect is only in the finish.

dmaacdd has it right but for his last move, where the tail was brought
around not "away" but near to the knot and makes the forbidden
Half-hitch; knot4u goes wrong on the turn but aces the finish.
And, again, it's sort of 6 of one, half-dozen of other, re that turn, perhaps
-- it's the finish orientation that provides the nicely locking/nipping hold.
And in both cases, the loaded SPart (if pulled as shown) puts added
pressure on the nipped tail.  (And I think one could finish with a sort
of Reversed Ossel Hitch, for like nipping.)


Btw, it seems to me --and was so presented by Gary Storrick's site (which
I think remains NA until he has time to devote to re-constituting it)--
that an extended *Cow*-oriented series of Half-hitches does a
better job at gripping than the like *Clove* series (Storrick named
such a structure "Hitch Series", IIRC (Bob ... ?) ).

I like the way this particularly oriented "cow" structure nips the end
within itself --i.e., independent of pressure/proximity to the
hitched object (!).  The stopper finish is also good, but one could
say is dependent upon there being close proximity to the object.

--dl*
====
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: DerekSmith on July 28, 2010, 07:26:49 PM
The overlaps take away some friction from the pole (where the friction should be) and apply that friction to the overlapped portion of the rope.  Further, where wraps do NOT overlap in those other gripping hitches I mentioned above, the load applied to the multiple wraps is transferred throughout the multiple wraps, and the friction to the pole therefore increases.  In your knots, because of the overlaps, that extra friction is non-existent.

Hi K4u,

You have made an interesting observation.  One that at first sight is logically true, but on closer inspection turns out to be the opposite.

The frictional grip between the rope and the pole is a function of three aspects - the coefficient of friction between the rope and the pole - the area of contact - the pressure of contact.  In turn, the pressure of contact is a function of the tension in the rope, which as it wraps around the pole translates into a force in towards the centre of the pole, pressing the rope onto the surface and so increasing the frictional grip.

It is true that by taking one line over another, you are removing its contact from the pole, so it cannot have any friction with the pole, but the twist comes from the fact that there is tension in the line and this is manifest as a pressure onto the line below it which significantly increases the pressure of the lower line onto the pole and proportionally increases the rope to pole friction.  In addition to this 'transferred' friction, there is pressure from the top rope upon the bottom rope which (as you pointed out) causes friction between them, and it is highly likely that the coefficient of friction between two ropes is greater than between a rope and a slippery pole surface, so at each crossing point, the ropes are gripping one another quite strongly and 'locking up' the structure quite effectively (try it, load up a KC and then try to move one of the top ropes).

Derek
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: dmacdd on August 02, 2010, 12:58:15 AM
"Icicle Cow Hitch"

(http://i32.tinypic.com/ejcaq.jpg)

Dress tightly before loading.

Actually, this holds extremely well with a downward load without the bottom cow hitch, as I have found by extensive experience with
(http://davidmdelaney.com/icicle-hitch/icicle-hitch-step-4.gif)
which lacks only that bottom cow hitch.
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: Dan_Lehman on August 02, 2010, 05:13:01 AM
Actually, this holds extremely well with a downward load without the bottom cow hitch,
as I have found by extensive experience with <photo of relatively fine/small cord
on a smooth object> (!!).

Whoa, that simply cannot be:  if you take a strict, little-wiggle parallel
away-from-coil pull, it can hold; but much of any angle to this pull
and that skinny tail will go screaming out of the non-existent nip as the
hitch's collar is pulled away from the object!  Do Not Pass GO !

--dl*
====
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: dmacdd on August 02, 2010, 07:13:34 AM
Actually, this holds extremely well with a downward load without the bottom cow hitch,
as I have found by extensive experience with <photo of relatively fine/small cord
on a smooth object> (!!).

Whoa, that simply cannot be:  if you take a strict, little-wiggle parallel
away-from-coil pull, it can hold; but much of any angle to this pull
and that skinny tail will go screaming out of the non-existent nip as the
hitch's collar is pulled away from the object!  Do Not Pass GO !


You mean like this? (See attached photos.)

It holds very well at angles from 0 to 40 degrees on my marlinespike with 1/16" / 1.6 mm braided nylon cord.  (About 10 lbs force in the photos from my right hand.)

It holds very well at angles from 0 to 40 degrees on a 28 mm wood dowel with 1/8" / 3.2 mm hollow braided nylon cord.
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: dmacdd on August 02, 2010, 08:26:05 AM

You mean like this? (See attached photos.)

It holds very well at angles from 0 to 40 degrees on my marlinespike with 1/16" / 1.6 mm braided nylon cord.  (About 10 lbs force in the photos from my right hand.)

It holds very well at angles from 0 to 40 degrees on a 28 mm wood dowel with 1/8" / 3.2 mm hollow braided nylon cord.

I just tested it with a half hitch continuing around in the same direction as the main body of turns. (This looks like a rolling hitch (ABoK 1734) with extra turns before the finishing half hitch, but the pull is in the opposite direction to that on the rolling hitch. k4u had a picture of this earlier in this thread.).  It holds well to 90 degrees, and just as well at small angles.

So I would have to advocate something other than the hitch shown in the photos in my previous posts here. I'll change my web site. 

I continue to like the well pipe hitch as being the most obvious simple smooth pole hitch -- six or so turns away from the direction of load then a clove hitch around the standing part with the tail.  If you want to make it secure against jerking, you can make a multi turn buntline with six or so turns away from the direction of load then an inverted clove hitch around the SP with the tail.
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: Dan_Lehman on August 02, 2010, 07:07:25 PM
Actually, this holds extremely well with a downward load without the bottom cow hitch, ....

Whoa, that simply cannot be:  if ... .  Do Not Pass GO !

You mean like this? (See attached photos.)

It holds very well at angles from 0 to 40 degrees on my marlinespike with 1/16" / 1.6 mm braided nylon cord. ...

Okay, yes, it can hold when carefully dressed & set; but it's
critical to get that tail nipped just so, rather than inevitable that it
will hold -- and a big danger lurks of spilling.  (If one can get the tail
positioned more towards the coil and against the collar/cross-part
then it will be further nipped --and at many angles-- by the SPart.)
But I'm concerned about intermittent loading and less-careful dressing.

In sum, there is a rope-on-rope nipping that can be effected, even with
the relatively large object; but the structure is not a good one to employ
in such cases.   Whereas some of these others, where the rope-on-rope
nipping is effected deliberately and more surely/stably, are sure bets.
(Along the lines of thought here, one might consider the Ossel Hitch on
a spar (i.e., an object approximately 3-5x rope diameter) vs. this same
hitch in reverse (pulled by the tail) --the former won't hold as space
opens where nipping  should occur; the latter nips in the rope tangle,
independent of the object.)

 - - - - - -

There can be subtleties of dressing & setting of these friction hitches.
I found one case where the ProhGrip/Blake's wouldn't grip but slide
until I loosened it such that there was some greater spiral at
the start and less turn -- i.e., the angle of incidence was more
towards the  parallel and away from the perpendicular.

It seems to me that loading the near end of the coil will work
better, as loading the away end can bring pressure against the
coil without tightening it (as the SPart bears into the coil), whereas
on the near-pull structures, the extension of the coil occurs with
a tightening effect on it.

--dl*
====
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: Dan_Lehman on August 09, 2010, 04:59:22 AM
   What is a -slippery- vertical pole ? The shank of an eye-less oversized hook.  :)  Should we try fishing knots, that tie lines to hooks, as gripping hitches, possibly better than the above ? Just a -naive- quick question.

I've been surprised to see some that do, i.e. some hooks
that have no eye (though sometimes something of a
different shape at hook's unsharp end).

But, no:  consider that fishing knots can be set with high
relative (to tensile, to expected loading) loads; not so with
rope (conceivable, but no practically the case).  And then
consider also that those fishing knots aren't expected to
UNgrip and be repositioned.

--dl*
====
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: Dan_Lehman on August 09, 2010, 07:15:41 PM
Note that those "eyeless" hooks are not simply straight shanks
-- they have that flattened knob on the end, at an angle.

Some of these knots sure look dubious re strength, IMO -- in
that there is that hard, 1-diameter turn of the SPart going
through coils that aren't tightened by loading, only setting!?

One of the Strangle forms --roughly the center image-- has the
end exiting beneath where it would normally cross over the
shank --wonder if this is intended or some artistic invention?

--dl*
====
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: knot4u on August 09, 2010, 10:56:02 PM
I wonder, on a vertical pole with square cross section, would the same task be more or less difficult ?

That's MORE difficult, at least with the hitches I've tried from this thread.  The friction is concentrated primarily on the pole corners.  The square pole also experiences more stress and wear because of the hard forces at the corners.

In contrast, the round pole experiences uniform friction (and more friction) on the entire circumference of the pole where the rope makes contact.  Also, there is less wear.
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: SS369 on August 09, 2010, 11:23:36 PM
Perhaps I missed it while rereading this thread, but are we looking for a hitch that is permanent? Or one that must endure all manner of tugs and cycles of loading/unloading? Be able to be relocated along the pole?

I recently had to remove a pump from a very deep well and the pipe (could be considered a vertical pole) was a very slick, moist plastic. I used a Prusik that was formed using a bowline as the base knot to fasten the working and standing parts together. I opted for three coils in 3/8 braided nylon rope.

The knot performed admirably and I was able to "inch" it up after getting the pump to break loose. I had the use of a come-a-long to do the initial grunt and from there on out man power did the rest. Not once during the 300 feet of pipe did the knot fail to grip, at least that I could discern.

It gets my vote, all things considered.

Scott
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: SS369 on August 10, 2010, 01:36:00 AM
Hi knot4u,

It is the first slide and grip I usually think of and it seems to always work well for the odd jobs I run into in the field of construction.  Works on irregular shapes pretty well too.  If you make a loop of some secure type first to bind the rope to itself and then use the loop to make the hitch.
And no way to install it backwards. ;-)
If I have to do another well pump removal, I will try to remember to try a Klemheist.

Tonight I tried the Prusik on a piece of polybutylene pipe I have in my dungeon (knot lair). I tied it using some recoil starter rope ( very tough cord) and tried valiantly to make it slip and though I had a tough time with anchoring the pipe, I used considerable strength and it did not slip. Was easy to untie even.

Scott
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: Dan_Lehman on August 10, 2010, 10:12:55 PM
... an ordinary snell knot, with no strangle knot buried underneath the snelling "envelope".

You're confused:  the Strangle knot is what all of these
images show that fit this general mold -- there is only a simple
knot "buried" within a Strangle, if you want to talk that way
-- but they all have it (it might take a partial unwrapping for the
simple knot's crossing to become visible, but it's there).

And in my note above, it was a similar difference in artistic presentation
that temporarily threw me off -- perhaps one could so dress the knot
and with deliberate setting have it hold, but otherwise it rolls around
into proper Strangle form.

And all this surprise at the knot not holding so well is precisely as
I explained:  in fishing line, one sets knots at much higher relative
loads; in rope, that potential is seldom realized, and the knots must
tighten under load a good deal beyond what is set.

--dl*
====
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: Dan_Lehman on August 11, 2010, 04:17:22 AM
My impression is that there are two distinct general patterns, and not just one.
In the first, in the ordinary snell knots, the lines buried under the ( many, at least 7) snelling turns run parallel to each other, they do not cross. The many turns is their mode of securing the tail.
In the second, in the twisted eight knots, the lines buried under the ( few, mostly 4) snelling turns form a strangle knot, they cross. The strangle knot is reinforced by the overlapping riding turns. The crossed ends are their mode of securing the tail.

Let me try again --though I expected that "Strangle knot" alone
was sufficient (Ashley #<whatever>).  In the square page of knot
images that you posted above,
 the top-left knot is a (Double) Strangle knot; it's seemingly parallel
 ends in fact cross, but not in this image -- they will do so in setting;

 the 2nd-from-top-left is <who knows>; it you slide it off of the
 object, it can be manipulated into a *Fig.12* knot (where this
 nomenclature takes "Fig.8" and adds to it as one end turns
 around the other before being tucked out through the loop
 formed at the other (u-turn) end of the structure (the initial
 member would be the Overhand, then Fig.8, Fig.9, Stevedore
 (Fig.10) ... and so on.
 In some thin, finely braided cord around a pencil, this knot
 didn't even hint at holding; in the Fig.12 orientation, and set
 firmly (given small size of material), it grudgingly imparted
 some resistance, but slid pretty easily;
 BUT, then loaded in the opposite direction --as you have
 suggested for the Strangle-- , it held surely (this taken immediately
 from the hard setting and loading of prior test) !?  Interesting;
 but I'd suspect though well gripping, it is not strong;

 Left-center is a Double Overhand knot which will tend to draw
 up into a Strangle (as depicted to its right).  Note why I favor
 "Strangle" as the base for the nomenclature and not "Overhand":
 looking at the full overwraps, one matches their number to the
 name, for "Strangle" (and for "Grapevine") --as the base knot
 has one, in contrast to the Overhand which has zero (and so
 a "Double Fisherman's" = a "(single) Grapevine", the latter
 having the easy wraps-count match, unlike the former).

...in fishing line, one sets knots at much higher relative loads; in rope, that potential is seldom realized, and the knots must tighten under load a good deal beyond what is set.

Quote
I agree. But there are some rope knots, like the constrictor, and in a lesser degree the strangle knot, where the riding turns keep the accumulated tension of the crossed ends constant, and, as a result, we have a highly tensioned, jammed, knot.
???

You completely miss the point:  it has nothing to do with the knot,
but with the relative force vis-a-vis breaking strength in setting it!
Yes, the Strangle will hold those 50#-force you impart:  now, in fishing line
of suitable strength not to have broken, that's rather close to the
maximum strain it can take; in rope, nowhere close.  (Okay, it's not
the breaking strength per se -- snap a magic wand on any gripping
knot and raise it's material's strength by 100 and it doesn't then
slip; but you get the idea -- fishing knots get set to a pretty high
percentage of the force they are going to see,
and to have the same condition for rope you would need to
take some quite unusual setting method.

--dl*
====
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: Dan_Lehman on August 12, 2010, 09:40:14 PM
the top-left knot is a (Double) Strangle knot; it's seemingly parallel
 ends in fact cross, but not in this image -- they will do so in setting;

No, there is the picture of a snell knot. The double strangle/ double overhand /double eight knot is shown in the bottom left picture.  No, they will not cross. They will not cross underneath the snelling turns, and get compressed by them as in the double, or quadruple, strangle knot. It is a standard snell knot, see the many web pages that have methods if tying it, and pictures of tied hooks with it. When the line is transparent enough, you can see the lines running parallel to the hook s shank.

Togologically, the knots are the same.
I find it impossible to believe that the top-left form can
be set tightly and maintain its apparent form -- those ends
must bear against something when they are set, and then
from which the tension is delivered to the overwraps;
and what they bear against is each other (as there is
nothing else).  Now, you go find your supposed photos
of actual snells that contradict this!

--dl*
====
Title: Re: Best Gripping Hitch for Vertical Pole
Post by: knot4u on December 28, 2010, 08:36:14 PM
The "Well-Pipe Hitch" is ABOK #504. You'll find that having more than four coil rings is unnecessary and can sometimes be problematic. Two Half Hitches will get the job done, but it is amazing how a Fixed-Gripper Knot instead of Two Half Hitches (or the Buntline Hitch knot) can noticeably improve the performance of the construct. A Fixed-Gripper Knot can be made tight, be pushed flush into the coil, stay put, actually aid the grip itself, and do the job noticeably better than either Two Half Hitches or (the component knot of) the Buntline Hitch.

The Fixed Gripper is awkward in this situation (i.e., replacing Two Half Hitches in Well Pipe Hitch).  Once the Fixed Gripper is set, it's a pain to perform additional tightening, which is almost always a good thing to do.  For reference, here is the Fixed Gripper (aka, Derived Hitch):
http://igkt.net/sm/index.php?topic=1839.msg12495#msg12495

In comparison, tying the Well Pipe by using Two Half Hitches (or Buntline) allows easy additional tightening.  It's also easy to remember even after months of not tying this knot.

I continue to like the well pipe hitch as being the most obvious simple smooth pole hitch -- six or so turns away from the direction of load then a clove hitch around the standing part with the tail.  If you want to make it secure against jerking, you can make a multi turn buntline with six or so turns away from the direction of load then an inverted clove hitch around the SP with the tail.

I agree.