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”
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.
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
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. 
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.
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
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.
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.
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.
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.
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.
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?
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.
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
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
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.
Let me try again --though I expected that “Strangle knot” alone
was sufficient (Ashley #). 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 ; 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).
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.
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!
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 agree.