Best gripping hitch around a tensioned rope

[xarax]

   Best gripping hitch around a tensioned rope. The tensioned rope, the "Main line", is of the same material and same thickness with the one used for the gripping hitch. The loading/direction of the end is close and parallel to the Main line s axis.

   In the attched pictures, I present such a Main line gripping hitch that has recently been devised by SS369, with some minor modifications made by me. In those pictures, I present only a 4+4 nodes/crossing points version. A 3+3 version would also hold, in many circumstances.
   Warning : It is strictly NOT permitted to minors to use this hitch.
   This hitch is NOT proposed as a climbing hitch.
   
   P.S. I have also to make clear that this knot, just like all the knots I have presented in this forum are "Why not" questions, not "How to" answers. For many reasons, we all like to use ready-made things and easy recipes, and we are inclined to do so more often than we should. The knots I have tied and presented in this forum do not address this need. They are more like a play with tangled ropes that may also be exploratory, or not. I try to Live Curious.     

   P.S. ( 2012-1-12 )
  This hitch is well known as the "Rat-Tail stopper" used around tensioned mooring lines. I was not aware of it at the time I first posted it as a friction hitch. I guess that now there is no point for me to try to comment on its effectiveness. 

[SS369]

Good day Xarax.

I just tried this affair out and what I am finding is that it is a little troublesome to tie with the 10.7mm BlueWater DYNAPLUS and the 1/2 inch BlueWater SPEC-STATIC ropes. So, yes rope particulars do come into play with knots.

It immediately made me think of tying two Prusic knots in tandem (one following the other) when I looked at your pictures (thank you for them).

What I expected to find and did was that the set of  "cow hitch" type coils closest to the load did most if not all of the gripping and the rest of the knot basically was along for the ride, so to speak.
I then tried clove knot based arrangements and found that they were very lacking in gripping power for this use. Subject to the ropes I used.

My testing facility for this is probably not as sophisticated as yours, but I did bodily load the contraption to gauge the performance and draw My opinionated conclusion. ;-)))

Didn't bother with photographing any of this.

SS

[xarax]

  Thank you SS369,

   I think that the "classic" hitches are based upon the large areas of contact between the multiple coils and the Main line, or the pole. The hitches I presented in this thread work differently: 1. The ropes strands of the hitch and the Main line cross each other at some points. 2. At a small area around those points, the surfaces of the ropes are deformed. 3.  On the surface of the Main line, these localised deformations, these "dents", act like obstacles that prevent the sliding of the hitch.
   In the ww hitches, we have something like the mechanism that keeps the warps of a fabric in their place, and prevent them from sliding though the wefts. The warps are pushed upon the wefts, and are squeezed in between the other warps. As in the case of the friction mechanism of a fabric, in a ww hitch we do not have the multiple coils and the large areas of contact of a "classic" friction hitch.

[Dan_Lehman]

What is the point for Best gripping hitch around a tensioned rope. ?

I.e., what sort of circumstances does this envision,
and might it be really about the same rope-problem
as tying to some other rigid object?  --pointing to the
qualifier "tensioned", which I take to deny the object-rope's
ability to bend or "dog-leg" and thereby aid gripping.

Another key factor is relative size & nature of cordage
and hitched object --the KC hitch being one favoring
considerable difference in diameters, cordage being smaller.

Not to expect "scientific testing" or anything, but it would
help to know what sort of testing/stressing has been put
to the knots put out for consideration --seems reasonable
to demand of the OP at least SOME sort of testing to at
least find the structure working in some minimal case.

E.g., I'd be surprised if the OP's knots of criss-crossed,
alternating over/under of strands, hitch gripped at all,
in the materials shown (firm, slick, climbing kernmantle)
--for it is roughly a KC hitch, which needs diameter difference
to gain purchase.  Giving this sort of structure (but I tied off
the ends w/a bolwine, for loading) a quick test in old, fuzzed
dynamic 11mm rope around somewhat thinner and much
slicker PMI <Won't-Bend> caving rope, it seems to grip
but with a pulley for loading, I see slippage begin --and
my object rope wasn't anchored in tension, even, so did
bend in sympathy to the hitch's gripping.

The "B hitch" is what Gary Storrick has called a "hitch series"
--repeated half-hitches/turns of alternating handedness-- ;
he believes that with the addition of further hitches, this
should grip on most anything.  That might depend upon
the non-gripping coming from slipping and not from the
cordage being too stiff to turn around the object and bite
(barring some setting that secures the structure until a tight
bite is achieved).

Scott says "I just tried this affair out" and that sounds
too singular for the plurality of ideas put forward already!?

In Xarax's bottom-shown structure that comprises a strangle
anchor with then interlocked, opp.-handed half-hitch turns,
and then the seemingly neat "cloverhand" final component,
I'd think that the 2nd component is of no use at gripping,
and the series should be of the cloverhands (my name for
a structure that can appear to be a clove hitch except that
the ends are on opposite side of each other in passing under
the overwrap, and topologically this makes an overhand ).
A risk in the cloverhand is jamming; but it seems a good way
to give more material for a stiff rope to grip, and to gain effect
in that way.

One tactic I've played with for getting more grip of stiff cordage
is lessening the helix angle of turns --not sure though that this
is ultimately (vs "seemingly") successful.  So, where one hitch
might take a single strand and wrap it around an object, the
revision would do this with two strands (though perhaps only
one will bear load, to grip), and thereby opens the helix angle,
and makes resistance to the bending a little less !?

One partial answer to my question of the point of this challenge
is to emply a hitching structure in an adjustable-eye knot, such
as the Midshipman's hitch : there, you see, the structure's S.Part
(I regard the *knot* to be what is hitched to this, and overall
we have a *noose-hitch*) will be loaded into and out from this
knot --out from, as one eye leg--, and so be more tensioned
than in some other cases (but less tensioned than an entirely
separate line such as a shroud, or a mooring line being hauled
tighter by a capstan, looking to be off-loaded onto some
<ack, what's the term here for this structure ? ______?>
other line, maybe to tie the bitter end to bitts, the release
the line onto that anchorage).


--dl*
====

[SS369]

Hello Dan and good day to you.

Quote: "What is the point for Best gripping hitch around a tensioned rope. ?"

Whose to know when a scenario might call for a gripping hitch on a vertical or horizontal line?
I can conjure up a possibility, but ultimately the use is not the real question I think. IMHO the question concerns a knot that has the ability to grip a rigid structure that happens to be a rope. And to discuss what makes it happen citing/sharing examples of things tried so they can be examined, discussed and debunked if needed.

Take a Tyrolean crossing. That is a tensioned rope and there is a need for a gripping hitch, albeit a releasable, slide and grip, gripping hitch. Yes, there are knots in use that have proved sufficient, perhaps not as good as something we're to find exploring this avenue of inquiry.

There might be some safety insuring uses as well that might be employed if the OHSA approved mechanisms are off sight for some reason and a need great enough.

Quote: "Scott says "I just tried this affair out" and that sounds
too singular for the plurality of ideas put forward already!?"

My comment was with specificity to one of the knots portrayed in the most recent pictures, the first one (sort of a "familiar"  response), not the whole thread. Yes, I am guilty of the negligence of failing to indicate that. Sorry.

Back on topic now. The KC hitch is good for rigid surfaces and I have tested it unscientifically in my shop on a 1.5 inch diameter by 6 foot long brass dowel. Using inexpensive 3/16 inch braided nylon it stuck like glue once set. The cord was tied to the ceiling joists, the knot en-wrapping the brass bar. I did indeed add some weight to the bar by pulling down. My opinion is that I could have broken the cord before the grip of the knot.
No, "stuck like glue" is not scientific terminology, but it is gets the point across for the average layperson.

I would expect no one to ever take my word for it and do the tests for themselves before employing Any knot in a safety or life endangering situation.

What is the point in having a forum about knots, their tying methods and their possible uses, if we can't pose a question or three to try and further our understanding of this itty bitty eclectic microcosm we find interesting.

This place/site is about sharing within the brotherhood of knot tyers, correct?   

   1. Promote research into all aspects of knotting
   2. Act as a primary source of reference and consultation
   3. Publish a periodical [?] about knot crafts and related subjects
   4. Form and maintain a library of books, papers, films, photographs and other materials associated with knots. [?] with a view to making information available to Members of the Guild and the general public
   5. Form collection of knots and knotting and work related crafts
   6. Promote and encourage knotting as an element in the education of children and young persons, and as a therapy for those who may benefit from such remedial activity
   7. Further promote the interest in knotting and associated activities, through its members, to the general public

Etc., Etc., Etc..................

Looking forward to yours and others input.

SS

[xarax]

    Thank you dan Lehman,

What is the point for Best gripping hitch around a tensioned rope. ?

  Let us say that we do not know, yet. If there is a successfull rope mechanism, I am sure that we will find an application for it !
  If we bult it, they will come !

pointing to the qualifier "tensioned", which I take to deny the object-rope's ability to bend or "dog-leg" and thereby aid gripping.

   Correct, up to a point. Because some bending, local deformation of the absolutly straight line, would be inevitable.

Not to expect "scientific testing" or anything, but it would help to know what sort of testing/stressing has been put to the knots put out for consideration --seems reasonable to demand of the OP at least SOME sort of testing to at least find the structure working in some minimal case.

   Oh, as I have said already, I prefer OPT (other people s tests !)
   I used some 10-11 kernmantle climbing ropes, and hang the weight of two people sitting on two quite heavy wooden chairs, and jump on them ! About the same test performed upon my "Pretzel" bowline, with equally satisfactory results. But a reason that I present those hitches here is to persuade somebody to test them in an "scientific" "experimental" way... And to provoke some "theoretical" examination and discussion, like the one we are doing now...
 

I'd be surprised if the OP's knots of criss-crossed, alternating over/under of strands, hitch gripped at all, in the materials shown (firm, slick, climbinkernmantle)
--for it is roughly a KC hitch, which needs diameter difference to gain purchase.

   I am glad I will surprise you !   However, I was surprised, too... The central idea came from SS369, and a climbing mechanism he showed to me. It is essentially the same mechanism that keeps the warps into the fabric, making them go over/under the wefts, and squeezed between other warps . See my attempt for an explanation at (1). As I have said there, D.Smith, or Ashley with the 1755, could have well discovered this hitch, had he replaced the pole by a rope.
   You should tie this ww hitch as I show it : In my pictures, the planes of the alternative half-coils are inclined to something like 45 degrees. It is interesting to see how the gripping power is decreasing with the less inclination. If the half-coils are not close to each other, the hitch will not hold, that is evident, because the Main line will not be squeezed enough by going over and under and in between the crossing strands.
 

.
The "B hitch" is what Gary Storrick has called a "hitch series"
--repeated half-hitches/turns of alternating handedness-- ;

   Thank you for this information. I am not aware of thiis work, I have to find the source and read about.

  One tactic I've played with for getting more grip of stiff cordage is lessening the helix angle of turns --not sure though that this is ultimately (vs "seemingly") successful.

  
   Congratulations ! You spotted this most interesting future of this hitch ! Varyng the inclination of the half-coils relatively to the Main line axis do change the gripping power, that is for sure, because, after some point,it vanishes altogether ! But how much ? And which is the optimum value ? ( I believe there would be one or two optimum values, but this should be a mater of very careful experiments ...)

though perhaps only one will bear load, to grip

 That is a most important point . No ! Both legs of the hitch should grip the same, and this symmetric position and loading of them would be much beneficial for its gripping power . How do  know it ? I do not !  :)I "feel" it, and I wait somebody to look at this matter.
We had a lengthy discussion wit SS369 on this , but we have not reached any conclusions. I insist that the legs should be loaded evenly, so the one in not more straight / aligned, and the other more helical. SS369 is not sure about it. I also want to have the two legs of the hitch braided in a symmetric patten, so that the legs get in touch with the man line alternately, the one after the other, to prevent the one of them have a continous helical contact with the Main line,while the other get around them.
   When the one leg have a large, lengthy helical contact with the Main line, when the hitch is loaded, the contact with the man line can drag the hitch unevenly- and deform it. It's very interesting to explore the differences f the various weaving pattens to the gripping power ! My conjecture is that the symmetric alternative pattern would be the better. But who is going to prove or disprove this experimentally ?

1) http://igkt.net/sm/index.php?topic=2191.msg16938#msg16938
    http://igkt.net/sm/index.php?topic=2191.msg16992#msg16992

[Dan_Lehman]

Quote: "What is the point for Best gripping hitch around a tensioned rope. ?"

...
 IMHO the question concerns a knot that has the ability to grip a rigid structure that happens to be a rope.

Well, that begs the question, or should move to merge
with the more general topic of hitching to a rigid object,
rope or otherwise.

Take a Tyrolean crossing. That is a tensioned rope and there is a need for a gripping hitch,
 albeit a releasable, slide and grip, gripping hitch.

Okay, not so familiar with this, but if one needs to haul tighter
a taut line with the hitching line, to then tie off the hitched line,
that fits the bill (as I had mused re the mooring line & capstan's
tightening (and it is "stopper" that is used for the hitching lines)).

Quote: "Scott says "I just tried this affair out" and that sounds
too singular for the plurality of ideas put forward already!?"

My comment was with specificity to one of the knots portrayed in the most recent pictures,
the first one (sort of a "familiar"  response), not the whole thread.

So, the alternately wrapped KC structure.  --and in ropes similar to
those pictured, both in nature and relative diameters.  Alright, then
there are three of us in the same ballpark on that.
(I'm not going to bother trying to use either the new-seeming
--though chronologically, but not usage-wise, plenty old-- PMI
*Won't-Bend* (my rejoinder to "EZ-Bend", its flexible kin), or
aged & used & "cable-like" Bluewater ropes, in which 3-diameter
bending meets resistance!!

The KC hitch is good for rigid surfaces and ...

Got anything tapered for it to try?
(A long marlinespike might be the best test.)

What is the point in having a forum about knots, their tying methods and their possible uses,
if we can't pose a question or three to try and further our understanding of this itty bitty
eclectic microcosm we find interesting.

But itty bitty is also the resource base to be chasing these questions,
or else what's the point?  And if itty bitty is even an amount beyond
visible benefit, that's a point to note in regard to expending efforts.

--dl*
====

[Dan_Lehman]

though perhaps only one will bear load, to grip

 That is a most important point . No ! Both legs of the hitch should grip the same, ...

I think you missed my point : for a structure of a coil with
twin parts, have only one of them be load-bearing, the other
serves qua spacer to reduce the helix angle (think of the
Klemheist  somehow loading only one of its twins, or of
the ProhGrip having a twin inserted).  --so, I wasn't remarking
about the above knots.'

It is (or was) an opinion of Franz Bachmann (has some kind of
engineering background) given to me that he expected twin-loaded
coils to be less gripping than single ones.

But we must keep clear how dependent knots can be upon materials,
and to try to not think in the common terms of "this *knot* is ..."
but "this **material so-knotted** is ..." .

--dl*
====

[xarax]

   I think you missed my point : for a structure of a coil with twin parts, have only one of them be load-bearing, the other serves qua spacer to reduce the helix angle
   It is (or was) an opinion of Franz Bachmann (has some kind of engineering background) given to me that he expected twin-loaded coils to be less gripping
than single ones.

   But in a double line coil, the angle/inclination is in fact increased, not reduced, since a point in one line, after a 360 degrees turn, is two diameters, at least, apart from where it had started, not one. Am I missing it again ?
   However, I think you got mine. The two interlinked, crossed coils, should bear the same loading, if we do not want to end up with a deformed plait.Their
angle/inclination should be the same, I think, but SS369 is not concerned about that. I have a soft point in symmetry, so I would prefer a plait that is symmetric initially, and retains this symmetry even after its loading, as the ww hitches shown in the pictures. 
   

[Dan_Lehman]

   I think you missed my point : for a structure of a coil with twin parts, have only one of them be load-bearing,
the other serves qua spacer to reduce=>widen the helix angle

   But in a double line coil, the angle/inclination is in fact increased, not reduced, ...

No, my mistaken wording.  Yes, the nearly complete circle is spaced
farther apart, with the twin cord between the cord whose helix we're minding.

--dl*
====

[knot4u]

I tested the knot in the original post.  I differ somewhat with what Xarax said.  I don't think the hitch is that simple.  I don't think it's that simple to tie, and I don't think it's simple in its operation.

This hitch is not directly comparable to just about any hitch I know.  It does not behave like a combination of Half Hitches, Overhands or Round Turns.  It's kind of a new category with the way it behaves.  I haven't quite put my finger on it precisely.  I did talk about the related KC Hitch here:
http://igkt.net/sm/index.php?topic=542.msg17072#msg17072

I have to be honest and say this knot is not of great interest to me.  That's not a slight against the knot.  That's just more of a comment about me.  When I see a hitch, I imagine at least one application where I can use it.  Currently, I can't imagine any application where I would prefer this hitch over some other hitches I know.  Again, that's not to say the hitch is impractical because it may prove to be useful to me for an application in the near future.  Who knows?

[xarax]

   Thank you, Knot4u,

  I don't think the hitch is that simple.  I don't think it's that simple to tie, and I don't think it's simple in its operation.
   This hitch is not directly comparable to just about any hitch I know.  It does not behave like a combination of Half Hitches, Overhands or Round Turns.  It's kind of a new category with the way it behaves.  

  I agree 100% with all of these !   However, conceptually, when we see this hitch as nothing more than a 3 string braid/plait, where the central string remains straight, it starts to look simpler. And the way we weave those two strings around the central one is following an easy pattern. If we use both hands, moving them in a somewhat mirror symmetric way around the Main line, after some time we can learn to tie it very quickly.
  
   No other friction hitch, climbing hitch, whatever, comes even close with the anti-slippage power of this hitch ! If I want to be 100% sure that my hitch will not slip, I will use a 4+4, or even a 5+5 nodes ww hitch, and then I will sleep like a baby.
 

[SS369]

Back to you Dan.

Quote:
The KC hitch is good for rigid surfaces and ...

Got anything tapered for it to try?
(A long marlinespike might be the best test.)"

I will try this suggestion if I find a suitable taper or make one.

But that's for the thread on the KC hitch.

 

"Quote From SS
What is the point in having a forum about knots, their tying methods and their possible uses,
if we can't pose a question or three to try and further our understanding of this itty bitty
eclectic microcosm we find interesting.

Answer by DL

But itty bitty is also the resource base to be chasing these questions,
or else what's the point?  And if itty bitty is even an amount beyond
visible benefit, that's a point to note in regard to expending efforts."

And so we of Itty Bitty Land are the resource base? We are expending energy and efforts are being made, at least by a few members, but we wax intellectually, eventually to wane.

I think the point is being sailed around and around. The IGKT purports to be an authoritative body of all things knotty and so I ask, "Where are the results?" "Where's the data?" "Where are the graphics showing the knots of the world?"

Just because we talk loudly, does not mean anyone is going to listen.

Who has some Real data out there?

SS

[SS369]

Good day Xarax,

This B hitch has some good qualities, but I personally am finding drawbacks to choosing this over another.
In my own opinion, if a knot is too fiddly to tie or will exhibit an inherent insecurity, then it only gets cursory use and in most likely will be just a exploratory spring board.

I find this series of hitches and bends subject to instability in that if you don't set it just right Or the load is cyclical, then they slip.

For the bend to work much better it needs to have a significant ratio of rope to rope diameters and the smaller one be the B.
Using my anaconda-like, new Bluewater ropes, I have challenges like those indicated above. So those eliminate the use of this structure with these ropes. Rope qualities are a big consideration that can influence the choosing or devising of a knot.

I may be wrong and not having a accepted test facility to scientifically confirm this, I find there may be an optimal limit of nipping loops that will actually do the "work". The rest may supply support in keeping the orientation(s), otherwise just along for the ride.

>>>I think this needs to be tested more and on an actual already tensioned rope as the thread begs.<<<

There is a big difference between a hitch being applied to a tensioned rope and one that the hitch will be applying the tensional load to the main rope after setting.

So a test for this could be horizontal or vertical. The rope as tight as one can safely get it. Tie the hitch of choice and test its effectiveness.

I personally would opt for a vertical set up and then tie a foot loop in one end of the rope to be used for the hitch, then tie the hitch and use my body weight to load the hitch (slow loading and bouncing too). The hitch's SP (the load) should be swung through a series of angles away from the Main rope, IMHO.

If it passes this lightweight test it can go to the next round of the Knot War.  ;-)

SS

[xarax]

   Thank you SS36,
 
   First, I have to say that I see no opponent, whatsoever, in the "best hitch around  a tensioned rope" "Knot battle" !  So, the ww hitch will win hands down !  

  For the bend to work much better it needs to have a significant ratio of rope to rope diameters and the smaller one be the B.Using my anaconda-like, new Bluewater ropes, I have challenges like those indicated above. So those eliminate the use of this structure with these ropes. Rope qualities are a big consideration that can influence the choosing or devising of a knot.

  Of course ! If a rope can not be bent around one rope diameter, you just forget those hitches ! Perhaps to be able deal with such anaconda-type ropes, we have to feed up the loop opening itself, to pass the tails through the nipping loops, as Dan Lehman suggested, but I have not tried those variations. (1)

There is a big difference between a hitch being applied to a tensioned rope and one that the hitch will be applying the tensional load to the main rope after setting.

   Yes, indeed. I am more interested in the "difficult" case, that of a tensioned Main line. A solution to this problem would have many applications , that anybody can think of. But I see no enemy approaching, so I feel confident about the outcome !  

I personally would opt for a vertical set up...

   Yes, that is what I have done, also because I can not do otherwise, even if I should to, with my high teck two-chairs-hang-from-the-ceiling-of-the-kitchen laboratory ! Perhaps the next level would be more telling, but I find very difficult, technically AND conceptually, to reach it...I mean, persuade the housewife to sit with me and my son on those chairs...
  
1) I do not know if the real anacondas can bend their body around a one anaconda body section diameter, or not...Can they, for example, constrict effectively a female anaconda that way ?