A binder variation base on ABOK 457

[enhaut]

Thanks @ everybody for your pointers.

The Cat's Paw; thanks Luca, I was looking for the right english term.

@ Xarax; I have tested the double nipping loop, yes it gives good friction but takes away one knot's characteristic; the capacity to be loosen up efforlessly.

@ SS369 "I believe the performance is better is because the rope is soft/deformable and so closes down to one diameter and smaller."

So true!

I have tried a robust 12mm rope and found that it requires a stopping mechanism.  A good deformable rope will produce the best results.

Cat's Paw binder seems a good working name for this knot!

enhaut

[xarax]

I believe the performance is better is because the rope is soft/deformable and so closes down to one diameter and smaller.

  The poly is soft too ! I do not think that any small difference in stiffness between those two materials can produce such big difference in gripping power. However, your braided nylon may be much more deformable than a laid 3-strand poly - are those the ropes you tried ? 

[enhaut]

I have found a solution for bigger rope; the Cat's Paw has 3 "finger"

[xarax]

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[SS369]

The poly is soft too ! I do not think that any small difference in stiffness between those two materials can produce such big difference in gripping power. However, your braided nylon may be much more deformable than a laid 3-strand poly - are those the ropes you tried ?

I'm sorry that I didn't give an example with more specificity. The "poly" I was referring to is hollow braided polypropylene. Usually yellow in color. I have some in three strand laid also.
It is a waxy feeling plastic and not good for much.     http://www.dakotaangler.com/product/invincible-marine-hollow-braided-polypropylene-rope-keeper-177825-1.htm#seitemdesc
It deforms plenty, but the slickness does not invite confidence and it proves itself to perform poorly here in this application.

SS

[enhaut]

@SS369
Thanks for the link, I see what your are talking about.
It makes me wonder, do I have to try all these kinds of rope to prove test a knot?
I must admit that I am not a connoiseur in this matter.

enhaut

[SS369]

@SS369
Thanks for the link, I see what your are talking about.
It makes me wonder, do I have to try all these kinds of rope to prove test a knot?
I must admit that I am not a connoiseur in this matter.

enhaut

You're welcome enhaut, though I was primarily giving the link to clarify the rope to xarax. 

I don't believe you need to try all these kinds of rope to proof test a knot, though it does help one to understand the strengths and weaknesses of the specimen.
One of the nice things about a worldwide forum is that others can be helpful with this sometimes. 

If you have an offering that you'd like input on using some other kinds of material, that you don't have access to, ask and let's see if we can give you some help.

Keep tangling!

SS

[xarax]

I am offering the bull hitch based binder.

   I have still not made up my mind about this : Does the Cat s paw nipping/locking neck presented in this thread is worth the added complexity to tie, dress and pre-tighten the hitch, in comparison to the humble Cow hitch-based one, or not ? In the mean time, see two new pictures of this hitch, taken while I was trying to answer to this question... However, I think that, as farmers, we do have a new problem : with so many bovines around, the nomenclature of the Cow- and Bull-hitch based knots became crowded, and perhaps it is time to consider the use of some names of other members of the bovinae subfamily : buffalo, bison, yak.... . (1)

1. http://en.wikipedia.org/wiki/Bovinae

P.S. Since the time I wrote this, I had tried many Bull-like two wrap hitches, including various Cow-hitch based ones, placed "belly up" or "belly down" on the surface of the pole. The original, asymmetrically placed Double Ring knot is the simplest and the tightest of the Cow-hitch-based hitches - and it is TIB as well, so there is no reason to use any other.
 

[SS369]

  However, I think that, as farmers, we do have a new problem : with so many bovines around, the nomenclature of the Cow- and Bull-hitch based knots became crowded, and perhaps it is time to consider the use of some names of other members of the bovinae subfamily : buffalo, bison, yak.... . (1)

Would you like to go to ornithological or girding based names? 

I think less can be more in the case of these types of binders, but that is in consideration of the object(s) to be bound and the media to do the binding with.
If you were going to do a binder with say webbing, which form would you gravitate towards?
Or with a slippery material?

With the bull based (lol) binder the added complexity is not so very much. When you make the Larks head, just pass one loop through the other and take it around, then continue.

Does the enlarged nub offer anything real? Can the leverage imparted against the bound material in a sideways pull be of benefit?

SS

[xarax]

   If you were going to do a binder with, say, webbing

   I do not even know if we should talk about knots tied on webbing ! It seems to me that people are too fast to use the same word for two entirely different mechanisms, the first involving almost-1D flexible objects, and the second almost-2D foldable objects. When the material is sooo flat ( or when it can be flattened a lot, and becomes so flat ), the way the fastening works is completelly different from the ordinary knots - something like ori-gami ( folded-paper ), made of long strips... We do not consider an origami-made object to be a knotted object, do we ?

[xarax]

   Does the enlarged nub offer anything real ? Can the leverage imparted against the bound material in a sideways pull be of benefit?

   Yes ! The "enlarged nub" has a certain bulk, so when the wraps press it on the surface of the pole, it is forced to be squeezed a little did, and so, by its turn, it squeezes the ends, too, that penetrate it. That means its "locking" efficiency is enhanced - as we have seen in the case of the "simple-hitch-a-la-Gleipnir". A hitch where both ends can be locked more tightly inside the "nipping/locking" nub is a tighter hitch, it can be pre-tightened more, and so its ability to withstand a lengthwise pull is enhanced.
   By "leverage" I understand the effect due to the increased distance in between the entry point of the Standing End(s) into such an "enlarged nub" and the surface of the pole. Yes, this distance is always welcomed - and I have seen that effect in much simpler hitches, too. During the pulling of the end(s), the part of the nub in between the Standing end and the surface of the pole is squeezed by both sides, and this works like a brake, further inhibiting the slippage of the hitch along the axis of the pole.

[SS369]

   If you were going to do a binder with, say, webbing

   I do not even know if we should talk about knots tied on webbing ! It seems to me that people are too fast to use the same word for two entirely different mechanisms, the first involving almost-1D flexible objects, and the second almost-2D foldable objects. When the material is sooo flat ( or when it can be flattened a lot, and becomes so flat ), the way the fastening works is completelly different from the ordinary knots - something like ori-gami ( folded-paper ), made of long strips... We do not consider an origami-made object to be a knotted object, do we ?

I don't necessarily feel we should be limited in this discussion, as long as it is germane to the OP.

Webbing gets tied and used many places. I am sorry (only here conversationally) that I view some things from a climbing use perspective and others may not... It is close to my heart and I am passionate about it.

A grass bend is in the realm of webbing and had its use, though maybe in olden days.

Some electricians use webbing to pull wire bundles through conduits and might actually have to use a knot.

To salvage a ratcheting web tie down that has been cut could use a knot too.

I'll do my best to not throw limits on this, the OP's thread, it could lead to an idea for a new thread! 

SS

[xarax]

   A grass bend is in the realm of webbing and had its use

  My point is that the thing : (ordinary) knot = "grass bend", tied on rope, is an altogether different thing - mechanism / works very differently, than the (origami) "knot" = "grass bend", tied on webbing ! I know it sounds odd to people who read the past and current literature on knots, and can not "see" the entirely different distribution of tensile and friction forces inside and on the surface of the materials, the different way those 3D objects deform in space under heavy loading, etc. - but it is true nevertheless ! 

 

[SS369]

   A grass bend is in the realm of webbing and had its use

  My point is that the thing : (ordinary) knot = "grass bend", tied on rope, is an altogether different thing - mechanism / works very differently, than the (origami) "knot" = "grass bend", tied on webbing ! I know it sounds odd to people who read the past and current literature on knots, and can not "see" the entirely different distribution of tensile and friction forces inside and on the surface of the materials, the different way those 3D objects deform in space under heavy loading, etc. - but it is true nevertheless ! 

No disagreement with rope and grass behaving differently or grass and webbing differing slightly. But, there are different types of webbing materials and construction styles and these do behave at least similarly to ropes and are used as (part of a system (maybe climbing or prusiking)  ) with knots in them.

If this is an undesired tangent of the conversation, let it fall by the wayside if you please.

Since I have webbing and use it, I like to explore those possibilities. Along with rope.
I even try these constructs using laid rope to see if there are quirks with its use.

SS

[Luca]

Hi xarax,sorry for the extreme lateness of this reply

  Luca, I suppose you have tried those three variations, shown again in Reply#5 here[ http://igkt.net/sm/index.php?topic=4821.msg31427#msg31427 ], for some time now. If you would like to evaluate them, what grade, from 1 to 10, would you give to them ?
  I prefer the first one, and, if the rope is very sleek, I entangle the Tail ends with one "twist" : the result seems a rock-solid hitch - the only problem is how one unties this thing !

At this point I think you have done your trials, and have derived your own conclusions...
I personally have tried these binders using them around a bulky stack of old newspapers, and around some piles of large diameter with respect of the diameter of the rope used,so I have not yet tested them in a real "mid-air situation".
It is quite difficult,maybe especially as regards the two binders based on the Clove hitch,to make sure that the hitch component remains well compact:the problem is that, by pulling the free ends to tighten the binder around the object, the two "round-turned" components of the Clove hitch tend to stay loose,with consequent loss of time (and possibly also of patience ...) in searching the way to tighten ...
The Prusik version is perhaps a little faster and more intuitive to realize, but the described situation is not much improved(but I have to remember that these three binders are born from a precise request of Kieran http://igkt.net/sm/index.php?topic=4631.msg29976#msg29976 , so these binders have been designed to be realized only once, and then reused many times without ever having to untie and re-tie them).
In any case, at the time of that thread, to overcome the problem described above, I had thought of entrusting the "bite" around the tail ends exclusively to the round-turned components of the hitch, leaving slack the "bridge" that unites them,and using this same "bridge" by pulling it(unless one decides to use the knot upside down, with the "bridge" which in this case remains in contact with the surface of the wrapped object) in order to take the opportunity to unite and further tighten the two round turns ... do not know to what extent it is a good idea, but apparently it seems to work!
Or (but in this case the surface of the wrapped object must be large enough to allow it) the two round-turned components can be moved away from one another for than allows the length of the "bridge" ,to create two distinct points where the tail ends are nipped.
OK,I realize that I'm not answering your question ... well, the fact is that I can not do it!
The Prusik version seems a little more "easy" to dress and set,and the tail ends form angles of 90 degrees at the time of entering through the hitch component,but I am not able to quantify which of these binders maintains tension better than others, I think that depends a lot on how one succeeds to dress and set them(it's a struggle!) and the materials used.
Using the Prusik binder as described at the beginning of the post, I tighten this binder by pulling both the tails using only the(poor!) force of my arms,without using any sort of mechanical advantage,so I never found it difficult to untie it.
Trying to keep compact the knot's nub of the Prusik component, I think it's very hard to make sure that the two external turns of the Prusik are gripping at the same level of the two interior turns,so I do not know how much it's worth it compared to the use of a simple Girth hitch!

                                                                                                                        Bye!