International Guild of Knot Tyers Forum
General => Practical Knots => Topic started by: xarax on December 14, 2011, 07:17:16 PM
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This is the simplest symmetric bend I know - simpler even than the What knot (ABoK#1406), or the Double Harness bend. I believe that, if set, dressed and tightened carefully and properly, it is a safe bend with most materials. It would be interesting to compare its propertes with those of the more often cited relative, the What knot .
P.S. This bend was devised by Desmond Mandeville, and was named by him as " Tumbling Thief knot ".
See :
http://igkt.net/sm/index.php?topic=3716.msg27342#msg27342 (http://igkt.net/sm/index.php?topic=3716.msg27342#msg27342)
http://www.surreyknots.org.uk/65-tumbling-thief-knot.htm (http://www.surreyknots.org.uk/65-tumbling-thief-knot.htm)
http://www.igktnab.org/km/KM10.pdf (http://www.igktnab.org/km/KM10.pdf)
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I believe that, if set, dressed and tightened carefully and properly, it is a safe bend with most materials.
Any looseness allows the knot to fall into a form that readily rolls apart. The same thing occurs if either of the free ends gets snagged. Far from being safe, this bend based on the Thief Knot (http://notableknotindex.webs.com/reefknot.html) is not even remotely secure.
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Thank you roo,
Any looseness allows the knot to fall into a form that readily rolls apart.
The same can be said for the What knot (ABoK#1406). and, to a lesser degree, for the Sheet bend. This does not mean they are note secure bends...The great advantage of this bend is its outmost simplicity, and the minimum amount of rope bends.
this bend based on the Thief Knot (http://notableknotindex.webs.com/reefknot.html)
Obviously :), this bend is based on the Sheet bend...It is just as its name implies, a symmetric Sheet bend. I do not see any relation with the Thief Knot, figuratively or functionally. If we want to look for some bend that functions with a similar way outside the Sheet bend and the What knot, we might think of the Zeppelin bend. The tails of the Zeppelin bend work like the pivot of a hinge, they are loaded with shear more than with tension or compression forces.
Far from being safe, this bend ...rl] is not even remotely secure.
I have tested this bend with many climbing ropes, and I have found that, on the contrary, this bend is very secure and very strong as well. I understand that, on a superficial examination, this bend does not look secure, because the public equates knot security with complex, tangled structures, and does not believe that so simple a form can be safe. Most known bends are based on interlocked overhand knots, so the fashion pays little attention to simpler bends - like the Double Harness bend, for example. I believe that knot tyers can go further than this...If you want a symmetric bend with a minimum amount of curves, this is the simplest bend you can find and use... provided, as I have stressed in my introduction, that it is "set, dressed and tightened carefully and properly". So, I can say that this bend is depending upon the properties of the knot tyer more than the properties of the rope itself ! :) That should be a blessing for the knot tyer that knows what he is doing and why he is doing this, is nt it that so ?
I advice the members of this forum to study this simple bend, and try to explain its mechanism. We often believe we understand knotting, but our theories, or mental models, are not very satisfactory, and their shortcomings reveal themselves when they are confronted with simpler rather than more complex knot structures. When we attempt to explain a complex knot, we can hide our head under the sand easily, with a lot of blah blah. With a simpler knot like this symmetric Sheet bend, we have to understand more, to be able to analyze the less. Less is more difficult :), but not less safe or less secure!
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I have tested this bend with many climbing ropes, and I have found that, on the contrary, this bend is very secure and very strong as well.
You must not have a very high standard for security.
I noticed that you've glossed over my comment about what happens when either of the free ends are snagged. Have you tried this, Xarax? If so, what happened?
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I noticed that you've glossed over my comment ...
I do not "gloss over comments" by anybody... :) I reply extensively and exhaustively in all comments made by everybody in this forum, (which is a rare thing nowadays... :)), to the point that my replies are often so long, repetitive and sooo boring...
What happens when either of the free ends are snagged. Have you tried this, Xarax? If so, what happened?
I will answer to this question, even if it is evidently a rhetoric one. It happens exactly the same thing as it happend with the WhatKnot (ABoK#1406) ! Is this a rhetoric enough answer ? :)
Many bends are distorted when their free ends are forced to do something they are not planned to do... That is why they call them "free ends" in the first place ! :) It is expected that such a simple construction will be destroyed if its free ends change their position into the minimal knot nub that holds them fast. A simple knot form is more sensitive to even small changes than a more complex one. If the bend is held under constant tension, which is often the case in many applications, and if the ends are left "free", there will be no problem of safety or security in this bend.
As I have said, we have to compare apples with apples, and this bend with the Sheet bend or the Whatknot (ABoK#(1406). Horses for courses.( My reply had touched a number of other points that I believe are also worth noticing :)).
It would also be interesting to try this bend with steel cables, or even electric wires. Besides having one only curve per link, it consumes a minimum amount of rope, a property that might be helpful in some applications.
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This is the simplest symmetric bend I know - simpler even than the What knot (ABoK#1406), or the Double Harness bend. I believe that, if set, dressed and tightened carefully and properly, it is a safe bend with most materials. It would be interesting to compare its propertes with those of the more often cited relative, the What knot .
I can't get this knot to hold at all in thin polyesterline (2mm). I'm able to pull the knot apart in one motion, even with super long tails.
It's better in thicker polyester, but it's still suspect. It slips and stops when the the three-braided structure of the rope is messed up. You need to be careful not to tie this knot wrong, and when you tighten the knot you must pay attention so it doesn't form an unwanted structure.
The structure is very simple yes, just two half hitches. But you are also very close to a fisherman's knot.
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Thank you Hrungrir,
I can't get this knot to hold at all in thin polyesterline (2mm). I'm able to pull the knot apart in one motion, even with super long tails. It's better in thicker polyester
I believe that the problem with the small diameter cord you use, is that you can not manipulate carefully the strands in their correct position relatively to each other, because fingers can not handle such small diameter objects with the precision required here. So, I guess that the root of the problem is not the material, but the scale. I use kermantle climbing ropes 9 - 12.5 mm thick, that I can handle easily ( and I can see what exactly am I doing, without glasses :) ! )
Now, pay some attention to this, please. This is not a bend that works like most of the others we know, where some bight shrinks, and nips a strand that goes through it, and, beyond a certain point, the friction forces prevent the slippage of this strand and secure the tail completely. The mechanism of this bend is depending upon shear more, rather than friction forces. So, if this bend is not set correctly at the first place, and taut in this place right from the beginning, it will not hold better at any time after this - because the pulling of the standing parts do not shrink any bight, to make the friction forces around a strand sufficiently strong to secure the tails. Pulling the standing parts further will make no difference, and an initialy incorrectly set bend - where the shear forces do not act properly as they should - will not hold at any time afterwards, however super long are the tails ! :) I believe that this peculiar property is the most interesting thing, because this bend, as I said, "is depending upon the properties of the knot tyer more than the upon the properties of the rope itself ". Read my lips : this bend works "if set, dressed and tightened carefully and properly". Try larger diameter ropes, and make sure you put the tails in the correct position relatively to each other, so that shear forces would have the chance to act, right from the beginning. Less is more difficult ! :) ( A fair price to pay). That is the nice thing with this bend : if one does not understand it somewhat, he can not tie it at all ! In other words, a blessing from the Knotworld for the knot tier.
Try it with larger diameter ropes, make it hold before the final tightening, and you will see what I mean.
The structure is ... close to a fisherman's knot.
No, not at all. The fisherman knot works in another interesting way : the volume of a stopper can not penetrate through a small diameter bight, because it is larger, bulkier than the diameter of this bight. The two overhand knots serve as two simple stoppers, and, as the tail of the one link goes through the nub of the other, they can not penetrate through each other. The stoppers are depending upon their internal friction forces to remain bulky and not degenerate into a straight line, which could easily pass though. So, a fisherman knot will work, (although not with the same efficiency, of course) even if it is incorrectly tied, and we have only the tail of the one overhand knot going through the nub of the other. The fisherman knot is a superb bend, one of the best we have, just one click below the Zeppelin bend. However, it consumes a lot of rope, in a degree that we can say it is not economical... On the contrary, the symmetric sheet bend is the most economical symmetric bend there is and could be. However, it should only be compared to the ABoK#1406 and the Sheet bend, not to more complex, overhand knot based bends, like the fisherman s knot. Most of the bends based upon interlocking overhand knots work in this easy way we are accustomed to, where you set the bend and you just pull the standing ends until some bights get small enough, and the friction forces upon the penetrating the bights tails get larger and larger, and, eventually, the tails are secured. In short, set it and forget it...With this bend, you have to tighten it first, make sure the tails are at the right place relatively to each other, only then forget it. Something similar happens to the closest relative of this bend, the ABoK#1406, and also, to a lesser degree, to the Sheet bend.
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Did you get your bend to hold when using two ropes of either different materials or of different diameters?
The structure is ... close to a fisherman's knot.
No, not at all. The fisherman knot works in another interesting way :
That's not what I wrote at all. Re read the sentence from my previous post. What I meant is: you are only one step away from the fisherman's kot.
Have you seen the Double Harness Bend? http://www.Layhands.com/Knots/Knots_Bends.htm#DoubleHarnessBend
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Did you get your bend to hold when using two ropes of either different materials or of different diameters?
The material does not seem to matter. I have tried it with using many pairs of two different climbing ropes, which have different sheaths ( nylon, polyester, polypropylene, or a combination of them), and also different cores. However, their properties are more or less similar ( similar stiffness, for example ).
I have not tried it with ropes of different diameters, because I think that its mechanism clearly dictates ropes of the same diameter. The same can be said about the ABoK#1406 - but not for the Sheet bend. Anyway, I see no purpose of wasting the advantages of a symmetric bend, by using it with ropes of different diameters.
Re read the sentence from my previous post. What I meant is: you are only one step away from the fisherman's kot.
Ok. You wrote ;"you are also very close to a fisherman's knot."(sic), and I have misinterpreted it. Anyway, as I said, the fisherman s knot consumes a lot more rope than the symmetric sheet bend.
In this sense, you are also one step away from the Zeppelin bend, which functions in a similar way, using the resistance of the rope to shear forces. The fisherman s knot works in an entirely different way, as I have tried to describe/explain in my previous post.
Have you seen the Double Harness Bend? http://www.Layhands.com/Knots/Knots_Bends.htm#DoubleHarnessBend
Do you mean if I have ever seen a Double Harness bend ? :) It was in the ABoK, the last time I remember... I guess you have seen my post about it, at (1). I believe that the "short" Double Harness bend is, in a sense, even "simpler" a knot than the "long" one, but I can not explain this in a satisfactory way. As it is shorter, it is more compact, and looks more efficient. However, although it is a neat small bend, it can not be compared with the symmetric sheet bend in terms of economy and effective use of a minimum amount of material.
1. http://igkt.net/sm/index.php?topic=2851
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I have tested this bend with many climbing ropes, and I have found that,
on the contrary, this bend is very secure and very strong as well.
!? How on earth did you find it to be "very strong"?
--or secure, for that matter. What were these tests
you claim? --more than some suspended chair, I hope!
My surmise is that when push comes to shove, this knot
will show shortcomings for its brevity --esp. if the joined
ends are not equal in nature. (The careful setting you
suggest implies some uniformity of behavior of the ends
upon loading, which might not be the case, for differences
of surface condition (friction) and elasticity & compression.)
I suspect the one end that might straighten more than
its opposite to lose necessary friction to stay tied.
If you want a symmetric bend with a minimum amount of curves,
this is the simplest bend you can find and use...
Actually, the squaREef knot is the minimal end-2-end joint
(and a good deal more use-tested than this). It also has
an arguably better claim for being some symmetric sheet bend
--in that the original arose from bending a line to a clew,
essentially setting the nature of the bend as a hitch
where if symmetry were to be achieved it would be in
making the hitching line reflective of the clew.
As for material efficiency, I doubt that this knot has much if
any advantage in reality, esp. concerning its nature and one's
natural inclination to leave longer tails than one might endure
with something else, such as the dbl. harness bend .
There is a measure of consumed material in which one can
mark exit points of each part and then measure the material
consumed, and put it divided by rope diameter. But this strict
measure omits consideration for material needed to effect (tie)
the knot, and of what might be desired as a safely long tail.
Even with the strict measure, though, I think that the above
knots will prove close.
Which is not to take away from the fascinating working/existence
of this simple knot --a late discovery for me (one that IGKT's late
Desmond Mandeville presented among his "trambles" through
the knotting universe, well prior my awakening to it).
--that subtlety of positioning the tails just so and TA-DA,
a joint is formed!! :D And it's one that "forcibly unties", per the
forces Roo notes --haul on the ends.
--dl*
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It doesn't hold for me in bootlaces and paracord. Also, for such a simply bend, it's rather easy to tie it wrongly. It may be topologically simple, but it's not simple to learn if you know what I mean.
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Thank you Dan Lehman,
Which is not to take away from the fascinating working/existence
of this simple knot --a late discovery for me.
--that subtlety of positioning the tails just so and TA-DA,
a joint is formed!! :D
I start from your last remark - which should have been the first, if your heart were as young as your brain. I am only an amateur neοphyte to the field of knotting, and it is natural for such a person to feel this awe for something that is so wonderful - almost marvelous - as a simple knot. However, when a veteran like you is also able to still feel the same thing, after all those years and all the unavoidable wear time imposes on things, this proves something about him, Ι believe, that should not go unnoticed. So, I take the liberty to repeat my call/request : Publish whatever you have in your notebooks, in an ordered and systematic way, if possible.
!? How on earth did you find it to be "very strong"?--or secure, for that matter. What were these tests you claim? --more than some suspended chair, I hope!
:) No, I have made some small steps beyond that stage, and I am performing more elaborate destructive tests, which I am going to publish in due time. I use a simple hydraulic truck jack, I measure the breaking forces, and I plan to test all the known bends, on a (cheap) 1/2 inch - 12.5 mm nylon rope.
if the joined ends are not equal in nature...this knot will show shortcomings for its brevity.
I have not tested this bend s strength for pairs of different diameter or composition. As I have said, this is a minimal symmetric bend, and is expected to perform only with two ropes of the same diameter and of similar resistance to shear forces. I have seen that the surface friction characteristics, as well as their elasticity would not matter a lot - provided that are similar, as it happens with the most of the common materials. This is a knot that works using shear more than friction forces.
the square knot is the minimal end-2-end joint (and a good deal more use-tested than this). It also has an arguably better claim for being some symmetric sheet bend
Absolutely not ! The square knot works is using friction forces more than shear forces, as most bends do - with the exception of the ABoK#1406 and the Sheet bend. It is not the way we use the bend that relates it with the Sheet bend, but the way it works. And it works just like the ABoK#1406 and the Sheet bend, obviously. It would be nice if Derek Smith would join this discussion, with his explanation of the elementary knot mechanisms in general, and of the Sheet bend in particular. Given long enough tails, if we pull the standing ends of the square knot, it will eventually lock, sooner or later. That is not the case for this bend, the ABoK#1406 and, to a lesser degree, for the Lapp and the Sheet bend(s).
Even with the strict measure, though, I think that the above knots will prove close.
No, because the percentage of the difference, or the ratio of the required lengths, is relatively large and significant, given the small number that represents the length in the case of the symmetric sheet bend. However, I have referred to this property only in passing... It is the beauty of the minimal structure that is worth admiring here, not the economy of the material. I am glad you are still able to appreciate it, whatever excuses you use to "gloss over" this feeling... :) Knotting is more a mental game than a material necessity, and if we lose admiration and passion, we lose the better part of it - AND the desire to explore it further.
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It doesn't hold for me in bootlaces .
It will hold only with material able to resist shear forces, and of circular cross section. That is expected because of the particular way it works, not because of its simplicity. The same will happen with the ABoK#1406, I guess.
Also, for such a simply bend, it's rather easy to tie it wrongly.
Actually, I think that it is easier to do fatal mistakes in simpler things rather than in complex ones. If a thing is depending upon only a few elements and a few relations between thiose elements, even a small mistake is able to decompose the whole structure entirely.
it's not simple to learn, if you know what I mean.
I may add that it is a difficult bend, a bend for the knot tyer, not the knot user, if you know what I mean. "If one does not understand it somewhat, he can not tie it at all ... It is depending upon the properties of the knot tyer more than the properties of the rope itself ".
Less is more difficult ! :)
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This bend is used extensively and successfully in high tensile wire fencing. Though this version is like a collapsed form of it. In fencing terms it is called a "figure 8 knot" I have also heard "figure 8 splice" used, but never bend for some reason.
http://www.agf.gov.bc.ca/resmgmt/publist/300Series/307131-1.pdf
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The so-called "fig.8 bend for cables and wires " (DANGER) shown at (1) has no relation whatsoever with the symmetric sheet bend discussed in this thread. It works only because of the friction forces along the two end line segments of the tails. It does not use the resistance of the material to shear forces, utilised at the two crossings of each symmetric sheet bend tail - where the tail is squeezed in between two rope segments, the strand of its own bight and the strand of the other tail s bight. In the former crossing, the two strands are perpendicular the one to the other, they bite each other, while at the second they move along a (short) segment of an helix, they embrace each other. The "fig.8 cable and wire bend" (DANGER) will almost never work for a flexible rope. In fact, it is the evil impostor of the bend we are discussing here. The symmetric sheet bend should always be accompanied by the skull and bones sign Ashley uses for ABoK#1406, but this "fig. 8 cable and wire bend" (DANGER) should be accompanied with something like the cross sign of a graveyard. ABoK#49 and ABoK1875 show (a part of) the same mechanism of the symmetric sheet bend that is used by simple hitches. However, the whole mechanism of the symmetric sheet bend is more complex/subtle than this, as I have tried to explain by the reference to each tail resisting shear forces, induced on it by segments of its own and the other tail s bight.
Although the evil impostor should never ever be thought of being used as a rope bend, the genuine symmetric sheet bend described in this thread will - most probably - work for cables and wires as well - and very effectively, I believe, ( I have not any knowledge and experience with cables and wires, so I could not test it with such materials - although I am very curious about the outcome of comparative tests, on cables and wires, between the genuine symmetric sheet bend and its evil impostor ).
1) http://www.agf.gov.bc.ca/resmgmt/publist/300Series/307131-1.pdf
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It will almost never work for a flexible rope
I agree with this, it is useless in rope.
I wasn't suggesting it's use for anything else other than monostrand high tensile wire where it excels, it is of very limited use in mild steel wire even.
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I'm surprised that you would think this bend to be considered safe. They claim you should never use the square knot as a bend but I'd much rather use it than this mess.
In my failed attempts to secure it, hauling on the SE's by my three year old rendered it useless. You seem to have actually been able to secure it because you've been able to somehow roll the orange half hitch on top of the white half hitch and give it a VERY false since of security. I simply can't get that to happen in the various materials I've fiddled around with.
Speaking of bends, ABOK 1451 is a damn good looking bend and unties beautifully yet gets no praise around here. Ashley seems to like it.
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I'm surprised that you would think this bend to be considered safe.
I do not think, I know, and I can prove it experimentally ! However, although I am disappointed for not been able to convey to you what I mean by those looong boooring posts, I understand you. Simple things are not easy, they are often more difficult and subtle than we think... I myself was amazed by how surprising safe and strong is this bend ( for ropes of the same diameter and similar material, as it happens with ABoK#1406.)
It happens, even to knot tyers with great experience, to confuse matters, because, after a certain point, they tend to think of knots in terms of other knots, and lose the ability and will to think of knots as rope mechanisms, as structures made of simple knot elements. It is the economy of thought that drives them to this slippery road, where, when they meet a new - to them - thing, they run the danger of seeing past it.
My dear TMCD, this bend has nothing to do with the reef family of knots in general, and the square knot in particular ! I had tried to explain it in looong previous posts...Ths bend is not working because of the friction forces around an embrace of two rope strands, that effectively blocks their motion relatively to each other and secures the tails. This bend is working because the tails are resisting to shear forces that try to bend them, as they are squeezed in between segments of the two bights.
They claim you should never use the square knot as a bend, but I'd much rather use it than this mess.
They are right. You are wrong. :) This bend has nothing to do with the square knot, it is not a "mess", it is a marvellous rope mechanism that you have not understood yet, so you can not tie it...but I am sure you will, eventually, if you tie it correctly an adequate number of times.
you've been able to somehow roll the orange half hitch on top of the white half hitch
Yes, because I tie it carefuly, knowing what I am doing and why am I doing it so, and I place the tails in the correct positions...You obviously do not follow neither my explanation of the working of this bend, nor my picture of the tightened knot, so it is expcted you will fail to tie it. I did not say that it could be easy, did I ? On the contrary, have stressed many times that it is a difficult knot to tie, because oftentimes the less is also the most difficult. However, do not confuse difficulty with insecurity ! There are many things and practices we use everyday that are difficult , but they are safe, if constructed and executed correctly. Do you think that an airplane is an easy thing to make or drive ? Does it gives you a FALSE sense of insecurity ? :)
It is amusing that I have compared this bend with - and only with - the Whatknot (ABoK#1406) almost a dozen of times at those posts, but nobody has ever told a word about their relation ! I guess that people feel shy and uneasy to criticize anything that is in the ABoK, but enjoy and feel proud to criticizing anything that is not ! :) However, everything that was said about this bend could have been also said for the ABoK#1406 and the ABoK#1875 as well.
There are hundreds of good bends out there...That does not mean we will stop examining bends and their mechanisms ! I myself have written many things about the ABoK#1451 and its close relatives in this forum ( search the previous threads). I am not impressed by any interlocked overhand knot - based bend, ( with the notable exception of this rope-made hinge, the Zeppelin bend ), probably because it is expected that, by using the amount of curvature those bends use, we will succeed to secure the tails. I am impressed by the simpler bends, like the ABoK#1406 and the Double Harness bend, because there is something unexpected, almost miraculous, in their efficacy. And the most amazing bend for me is this symmetric sheet bend, a beautiful little knotting jewel...that enlarges, by its mere existence, our view of what really is a knot .
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It may be topologically simple, but it's not simple to learn if you know what I mean.
Xarax won't like me saying this, but it's easy to make from a Thief Knot by shifting the ends, since the bend is just a deformed Thief Knot. But this bend has bigger security and stability problems that have no cure.
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it's easy to make from a Thief Knot by shifting the ends
True. This can be said also for the Sheet bend, and the evil impostor of this bend described in a previous post (Reply#14), In such a simple thing, even a miniscule change makes a big difference. In fact, this "shift of the ends" of the Thief knot produces an altogether new knot - that has no relation whatsoever with the parent knot, as I have tried to explain many times. The "new" knot works entirely diferently, and, if tied properly, of course, this bend is much, much safer than the Thief knot. With yet another "shift", one gets the evil impostor, which, with ropes, do not work at all ! So, can we say that the symmetric sheet bend is a knot that is just a deformed unknot, as the evil impostor essentially is ? :)
this bend has bigger security and stability problems that have no cure.
[this] bend is just a deformed Thief Knot.
True. There is no cure for ignorance. If one does not understand this knot, he can not tie it. And if one believes that this knot is a deformed Thief knot, I am afraid that he has not understood a thing ! :) This phrase, "this bend is just a deformed Thief knot", (sic), made me lough loudly :) ! Thank you, roo.
True : A straight line is just a deformed knot, and a knot is just a deformed straight line. :) :) :)
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This can be said also for the Sheet bend,
False. That would involve re-tucking.
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False. That would involve re-tucking.
No, It is true, because the false of a false is true... :) To say that "the symmetric sheet bend is a deformed thief knot" was as false a statement as it could be...In fact, it was not even wrong, and I doubt that it was even a statement... :)
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I have tried this simple bend in every cord and rope I have that I use for tying and evaluating new to me knots (3mm - 13mm). It works every time I tie it and it is secure.
The way I tie it seems to make it form easier.
See if this works to make it easier for those who may be having a challenge.
Tie a sheet bend, one that has the WE's on the same side, and snug up it a bit. Then take the non-crossed bight's Working End and cross it over it's own Standing Part and insert it down through the opening between the SP and the other's bight. Pull slowly and final tighten.
In firm rope or cord like Titan 5.5 it holds, does not slip at all using my suspended weight and after setting the knot tight I can not shake it loose. It unties easily either by working the bights back and forth or if the tails are long enough, just yanking them.
*I would not and do not recommend this bend for any life endangering activities!*
SS
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I have tried this simple bend in every cord and rope I have that I use for tying and evaluating new to me knots (3mm - 13mm). It works every time I tie it and it is secure.
The way I tie it seems to make it form easier.
See if this works to make it easier for those who may be having a challenge.
Tie a sheet bend, one that has the WE's on the same side, and snug up it a bit. Then take the non-crossed bight's Working End and cross it over it's own Standing Part and insert it down through the opening between the SP and the other's bight. Pull slowly and final tighten.
In firm rope or cord like Titan 5.5 it holds, does not slip at all using my suspended weight and after setting the knot tight I can not shake it loose. It unties easily either by working the bights back and forth or if the tails are long enough, just yanking them.
SS
Holding under a static load or only when the knot is very tight is a very poor standard of security. You seem to admit that any force on the free end makes this bend subject to catastrophic failure.
Describing this bend as secure is a good way to get someone killed, especially when bringing up climbing rope and talking about suspending human weight.
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Thank you SS369,
This is a (rare) case where a video would be of some help, I think, because the exact way one makes those moves you mention, every little detail of the whole knot-tying gesture, matters a lot - given the simple and fragile nature of this bend.
Try to tie it by manipulating the ends of a Thief knot - as roo seems to suggest - and see if it would be easy to you. I myself I am not accustomed to tie the sheet bend quickly, so I start from the beginning, I form one carefully sized bight, I keep the tail and the standing end of this bight crossed, perpendicular to each other, between my thumb and index fingers, and then I work the working end of the other rope with my other hand through and around this bight, as tightly as I can. Much more naive a tying method than yours, of course...
In fact, there is a number of different sets of knot elements we can see functioning in this bend, the pair of the opposed half hitches being only one, the most obvious of them. I see this bend as a more economical, shortened Zeppelin bend, where some parts of the paths the working ends follow, in the Zeppelin bend, are now missing. However, the working ends make a similar journey through and around the knot s nub as in the Zeppelin bend, they just follow shorter paths ! The pair of the tails play here the same role as in the Zeppelin bend : together, they serve as the pivot of a rope-made hinge. ( In the case of the Zeppelin bend, we can actually watch this hinge mechanism more clearly, as we can make the two links of a lose knot revolve around the axially placed pivot ). That is why I say that this bend is similar to the ABoK#1406 and to the Zeppelin bend more than to the Sheet bend or the Thief knot. It is the resistance of this pivot to shear forces, that prevents the whole structure from falling apart. In the Thief knot, we have rope strands that embrace each other, and, as the bights get smaller and smaller, the friction forces get larger and larger, to the point the rope strands can not move relatively to each other any more. We do not have strands at right angles to each other, like we have at the symmetric Sheet bend. In the case of the ordinary Lapp knot and the Sheet bend, we have a mixed situation, something in between the Zeppelin bend and the Thief knot.
Now, in this bend, as each tail is squeezed in between two rope strands, one from each link, they are safely secured in their position. Moreover, I think that a most beneficial thing is the particular way each tail meets the rope strand of its own bight - they are perpendicular to each other, so they bite hard the one the other, and the "dents" that are formed on their surface are deep and very effective in blocking their motion and preventing them to slide through the knot s nub.
I could have described this bend as a more secure Thief knot, because the way the tails bite each other do make this symmetric sheet bend a knot much more efficient than the Thief knot, and the slippage of the tails much more difficult. However, I have not made the mistake roo did, and confuse a topologically similar knot, that could serve as a parent knot in some tying methods, with the outcome of those tying methods. We can tie this bend starting from the Thief knot or from the Sheet bend,as you describe, but the end result is an altogether different animal, indeed. I have called it "symmetric Sheet bend" because the two links resemble the one link of the Sheet bend, but I could very well have called it ABoK#1406 b - as the ABoK#1406 is its closest relative, in appearance as well as in function.
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It is the resistance of this pivot to shear forces, that ...
Is no more "shear" than that of most(?) other knots,
such as Ashley's bend #1452 (or #1408). Making
a big thing of this is misleading. Tails are nipped, hardly
a unique quality; they have axial forces on them as well.
I have tried this simple bend in every cord and rope I have
that I use for tying and evaluating new to me knots (3mm - 13mm).
It works every time I tie it and it is secure.
That's a promising but strictly unhelpful comment --in that
we don't know what, exactly ... . I'd guess that you have
paracord, which some have claimed won't cooperate? (I
guess that I, too, have some, SOMEwhere, but haven't
yet found where.) For getting close to that, I tried some
hollow-braid binding cord as is common w/commercial-fishing
gear, and it holds there as well. It does take careful setting.
And after a fairly good stress w/the pulley (of a sling joined
by the knot), it did succumb to a tug on the tails to capsize
into the opposed-halfhitches form, from which it was then
loosened further. That might be a reason to use this knot,
but I suspect most folks will prefer the carrick bend here.
A main challenge in tying the knot is getting the turn open
enough to correctly position the nipped tail, but open only
minimally, as best possible, to that the nipping doesn't
severely fold the tail into this turn --tricky balancing act,
as tightening the turn much will threaten to mis-position
the tail.
--dl*
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Holding under a static load or only when the knot is very tight is a very poor standard of security. You seem to admit that any force on the free end makes this bend subject to catastrophic failure.
Describing this bend as secure is a good way to get someone killed, especially when bringing up climbing rope and talking about suspending human weight.
Hello roo. Your statement holds true for so many knots, bends and whatevers. A proper knot, for the most part, is one that is dressed to the point it needs to be. Some knots don't need much dressing to hold and some need quite a bit of fairing.
Do you use knots that are knot fully tightened regularly?
I have not suggested this exploration to be used in any manner, I have just iterated the materials I use for my own tying and evaluating.
Regardless of what you are driving at, I found this knot to be secure during the loading and during the flogging of it unloaded. It will stay tied under tension even using 1/16 inch aircraft cable.
I have not said that "any force on the free end makes this bend subject to catastrophic failure."
I did say, "It unties easily either by working the bights back and forth or if the tails are long enough, just yanking them." And this is a property of a good knot, the ease of untying."
Not all knots are best suited to all tasks and it behooves the tyer to be smart and pick wisely.
Under tension it is my belief that it would take a deliberate act to cause it to come undone. My impromptu test did include some tugging and bouncing which took it out of the realm of mere "static load".
No, I would not use it for life endangering activities. For those events I use other more proven affairs.
But that does not interfere with my desire to explore more possibilities.
Did you find anything good about this knot?
SS
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I have tried this simple bend in every cord and rope I have
that I use for tying and evaluating new to me knots (3mm - 13mm).
It works every time I tie it and it is secure.
That's a promising but strictly unhelpful comment --in that
we don't know what, exactly ... . I'd guess that you have
paracord, which some have claimed won't cooperate? (I
guess that I, too, have some, SOMEwhere, but haven't
yet found where.) For getting close to that, I tried some
hollow-braid binding cord as is common w/commercial-fishing
gear, and it holds there as well. It does take careful setting.
--dl*
====
Hello Dan.
To list the sizes, materials and construction of each of the various cords and ropes I have at my disposal is a task that I feel unnecessary without a direct question concerning it, but, I will for you.
Yes, I do have paracord. I have Lacrosse cross-lacing cord, accessory cord, prusiking cord and climbing ropes of many brands. Cheapo poly-something or other from the big box store, hollow braid as well. I have manila rope, sisal, hemp and cotton multipurpose (mostly #72). Even some macrame of varying diameters of some synthetic shiny fibers. And the list continues....
If you want more specified data, please ask. Perhaps in pm as to not dilute the thread any more.
The point is not what I have, but that I use a fairly varied small collection to tie and evaluate some of the knots I encounter here. And that is what the "unhelpful" statement was saying.
Someone offers a tangle that looks interesting, I tie it generally using a select few of the materials available to me. If it has promise I take it to my ad hoc test facility. ;-)
SS
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snip...
It would be nice if Derek Smith would join this discussion, with his explanation of the elementary knot mechanisms in general, and of the Sheet bend in particular. Given long enough tails, if we pull the standing ends of the square knot, it will eventually lock, sooner or later. That is not the case for this bend, the ABoK#1406 and, to a lesser degree, for the Lapp and the Sheet bend(s).
snip...
Hi Xarax,
I would be happy to comment on this knot as it is truly an excellent example of cogging dynamics, and I agree with you that a simple knot is an ideal starting point to examine the machinations of a knot's workings.
However, This is the 'Practical Knots' board, and this is never going to be a 'Practical Knot' and I believe we have a duty not to promote it as such.
While I must agree with you that this exact form of dressing is strong and stable under load, it only takes a tiny tug on one of the ends to convert it into one of the two other massively cogging forms.
Even though it is one of the few knots which 'dresses itself' to the extent that it won't eat any of the tails as it is loaded, it is none the less only safe as a 'cerebral exercise'. To suggest to anyone with less understanding of a knot's functionality than you have Xarax, is I believe, foolhardy and irresponsible.
To that end, if the topic finds itself over in 'cerebrionics' then I will be happy to fawn over it.
Derek
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This bend is used extensively and successfully in high tensile wire fencing. Though this version is like a collapsed form of it. In fencing terms it is called a "figure 8 knot" I have also heard "figure 8 splice" used, but never bend for some reason.
http://www.agf.gov.bc.ca/resmgmt/publist/300Series/307131-1.pdf
The interesting usage brought to us by Benboncan has illustrated an important point reagrding 'cogging'
(http://igkt.net/sm/index.php?action=dlattach;topic=3716.0;attach=6327;image)
Knots which require a rotational element of cogging will probably lock up when made of wire because it flatly refuses to 'rotate' like cordage will.
Derek
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It is the resistance of this pivot to shear forces, that ...
Is no more "shear" than that of most(?) other knots, such as [/i]Ashley's bend #1452[/i] (or #1408). Making a big thing of this is misleading. Tails are nipped, hardly a unique quality; they have axial forces on them as well.
I understand that it is difficult (at least for me) to explain this difference, and it is difficult for a person not trained in engineering to understand it. In the case of this bend, as well as in the ABoK#1406, shear forces, - and the resistance of the pair of tails, functioning as as a rope-made pivot, to them - is paramount. I am not saying that shear forces do not play a role in other bends as well. In fact, they participate in the mechanism of any knot, alongside tensile and compression forces. However, if you manage to see the hinge-like mechanism, you will also see what I mean. Only in those three bends the principal role of shear forces is so pronounced. ( I can also think of a few other knots, like the Anglers loop, for example, where we have a similar situation). Of course the tails are nipped, like it happens in any knot, we could hardly have a knot without this function ! However, in most other knots, we have entangled bights, and the knots remain knotted because the tails are nipped as they pass through these bights, and they can not slip through. When the tails can not slip through the bights, these bights remain entangled, and the knot remains tied. This is a very different mechanism from the hinge-like mechanism of the symmetric sheet bend ( and the ABoK#1406 and the Zeppelin bend ), where we do not have entangled bights, but bights revolving around a common axis, materialized by the pair of the tails.
I do not make "a big thing of this", although I admit that I had the hope at least a few people, in this particular forum, would be able to mentally see this difference... Anyway, untill the time we can take pictures of loaded knots made by flexible transparent material ( a flexible plexiglass, perhaps ?), where we can literally see the distribution of forces into the bulk of the material, we can not prove or disprove any of our opposing views, can we ? :)
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Thank you Derek. It is always a pleasure for me to discuss with you about simple, fundamental knotting mechanisms.
This is the 'Practical Knots' board, and this is never going to be a 'Practical Knot' and I believe we have a duty not to promote it as such.
I agree. Let us move it to our brand new Knotting Concepts and Explorations, where it clearly belongs. I see it as an exercise, I could even dare to say a theorem of knotting mechanism. If it would ever be considered a "practical" knot, it would only be in the sense that it can solve a practical knotting problem of an experienced knot tyer, who knows what he is doing and why is he doing this. As I have stressed, it is a difficult knot, suitable for knot tyers only, and it does not take hostages.. :).
it is one of the few knots which 'dresses itself' to the extent that it won't eat any of the tails as it is loaded
Oh ! I forgot to mention that advantage ! :) I thank you for reminding it to me. It might be interesting to mention that the other three bends that work in a similar way - using the pair of tails as a rope-made pivot of a rope-made hinge - also do not "eat" much of their tails during further loading. The shear forces are very effective of inducing a large amount of friction, and block the slippage of the tails.
it is none the less only safe as a 'cerebral exercise'.
May be, but you know how useful have "cerebral exercises" have been , in the course of human history ! :) A cerebral exercise of half a dozen scientists, back at 1964 where most of the knot tyers - indeed, most of the people - in the world were not born, proved to be a hard, material reality a few days ago at CERN...In fact, it was proven to be the reality that gives to all matter its material substance, its mass :)!
I have said that this bend is a difficult bend , and should only be tied by people that know what they are doing, and why they are doing it. In fact, it is a very safe knot, in that it can not be even tied by other people, so no week-end knot tyer would ever dare to tie it... (Just kidding...) I have also said that it should be accompanied by the scull and crossed bones sign Ashley uses for ABoK#1406. In fact, it is not more "safe" or more "dangerous" than ABoK#1406, and I have not read anything in this thread that points to even one subtle difference between those two bends. People are alarmed with the security of this bend more than with the security of ABoK#1406, for one simple reason ; They knew the one, but they have not seen the other ! And the one is there, in their holy book, while the other is not. In short, nothing more than the well known knot tyers conservatism.
The great advantage of this bend is the lessons it offers to us, the widening of our view about bends in particular, and knots in general. I would try to incorporate the mechanism of this bend in more complex, and more easy to tie knots. For me, knots are more a mental game than a practical necessity, so a cerebral exercise is a welcomed thing - and a cerebral theorem, like this bend, is a Knotworld-heavens blessing ! :)
It is amusing that the knots I present is this forum are criticized as too complex or too simple ! I do not know what is the truth, but I
only hope that they are not too boring...
Derek, I know you could explain this knot using your elaborated system of fundamental knotting elements, and I would be glad if you will compare it to its evil impostor, and to the ABoK#1406.
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I would like to ask a question, related with matters discussed in this thread.
We have two knots :
1. On the one hand , the well known Thief knot. It is very easy to tie, very difficult to tie it wrongly, but it is a very slippery bend.
2. On the other hand, the relatively unknown symmetric sheet bend. ( It can be considered as a different dressing of the Thief knot ). It is very difficult to tie, very easy to tie it wrongly, but it is not slippery a bend at all.
The Thief knot is considered to be a "practical" knot, and it is almost never accompanied by the danger/ scull and crossed bones sign of Ashley. The symmetric sheet bend is not a practical knot, and it should always be accompanied by the danger/ scull and crossed bones sign.
The question is : Which one is really more dangerous ? The one that slips even if tied correctly - but it is easy to tie... or the other, that does not slip when tied correctly - but it is difficult to tie ?
My answer is this : the Thief knot has already killed - it will continue to kill, because it slips, and it is an easy to tie bend - many more people than the symmetric sheet bend will ever do... because the symmetric sheet bend does not slip, and it is a difficult to tie bend. So, I conclude that the Thief knot is much more dangerous than the symmetric sheet bend...( and I admit that I have asked this rhetorical question only to intrigue some answers by the (few) participants of this forum... :))
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Although the thief knot is a supposed "practical" knot, the practical-ness of it comes from the trickery it was supposedly used for. It was to potentially indicate that a sailors ditty bag security was violated by the assumption that a reef knot would be tied back instead.
How much it really remains a practical knot is a matter of personal choice.
But if we choose to categorize it as one then in my own opinion a Turks head knot is a practical knot. It has been used as a marker on a ship's wheel.
Just because we talk of it and refer to it in the Practical Board doesn't necessarily make it practical.
I don't use it for anything.
The OP bend could be practical if we found a good use for it in daily life. ;-) I find it meets the requirements of a good discussion knot, to aid further understanding of the forces in play to arrest/resist the linear material's movement.
For me it is not so much that a knot is dangerous or not, it is the tyer who could be the dangerous one. Knots don't kill, people do.
SS
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It is the resistance of this pivot to shear forces, that ...
...Is no more "shear" than that of most(?) other knots,
I use this opportunity to show another interesting bend (see the attached picture), that can be used when we want to connect two pieces of rope in a way that will allow us to disconnect them easily, and then repeat the same cycle many times. Now, this bend works exactly in the same way as the Zeppelin bend, but here the two ends can be separated, yet there remain some untied structures on each of them ( the slipped overhand knots ), ready to be utilized when the ends will be entangled with them again. It is just an example of the few bends that work using the resistance of rope to shear forces more than the other bends do. The symmetric Sheet bend we are talking about in this thread, its closest relative, the ABoK#1406, the "slipped overhand knot bend" in its crossed tails variation, shown in this post, the 2 U s hitches presented at (1), the angler s loop... in all those knots the resistance of the tails, that play the role of a rope-made pivot, is the principle reason those knots, once loaded, remain in one piece.
The tails working as pivots that keep opposed bights together, even if those bights are not hooked the one by the other, that is what characterizes the symmetric sheet bend - and make it very different from the Thief knot, from which it can be derived by a manipulation / different dressing of the tails. I am sorry that the people I have not been able to convince about this fact - which seems rather obvious, but is proven o be not so easily digestible - will miss some of the marvellous qualities of the symmetric sheet bend... and of with the Zeppelin bend, and all the other knots I have cited. We can know how to tie a bend, we can use a bend, we can even appreciate it a little bid, but we can still fail to enjoy it mentally, as an example - or even a beautiful theorem - of the wonderful KnotWorld.
1) igkt.net/sm/index.php?topic=3104
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I would like to ask a question, related with matters discussed in this thread.
We have two knots :
1. On the one hand , the well known Thief knot. It is very easy to tie, very difficult to tie it wrongly, but it is a very slippery bend.
2. On the other hand, the relatively unknown symmetric sheet bend. ( It can be considered as a different dressing of the Thief knot ). It is very difficult to tie, very easy to tie it wrongly, but it is not slippery a bend at all.
The Thief knot is considered to be a "practical" knot, and it is almost never accompanied by the danger/ scull and crossed bones sign of Ashley. The symmetric sheet bend is not a practical knot, and it should always be accompanied by the danger/ scull and crossed bones sign.
The question is : Which one is really more dangerous ? The one that slips even if tied correctly - but it is easy to tie... or the other, that does not slip when tied correctly - but it is difficult to tie ?
My answer is this : the Thief knot has already killed - it will continue to kill, because it slips, and it is an easy to tie bend - many more people than the symmetric sheet bend will ever do... because the symmetric sheet bend does not slip, and it is a difficult to tie bend. So, I conclude that the Thief knot is much more dangerous than the symmetric sheet bend...( and I admit that I have asked this rhetorical question only to intrigue some answers by the (few) participants of this forum... :))
I do not consider the Thief Knot "easy-to-tie" for the inexperienced knot tyer. Most who will tie it are somewhat experienced and very likely aware of its slippery nature. Those with experience are also likely aware that it is unwise to use a "binding knot" as a bend. Thus, we have the "Reef Knot" or "Thief Knot" and not the "Reef Bend" or "Thief Bend". I find it unlikely that the Thief Knot will often be used as a bend and equally unlikely that it is much of a "killer" or very dangerous. I also do not find the OP knot to be very dangerous for the same reasons.
DDK
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I find it unlikely that the Thief Knot will often be used as a bend and equally unlikely that it is much of a "killer" or very dangerous. I also do not find the OP knot to be very dangerous for the same reasons.
I thought the same thing of this insecure "bend" for much the same reasons until SS369 started calling it secure.
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Hello roo,
I'll stand by that statement I made about the OP bend being secure, at least for me. I would not use it for rappelling because there are more secure bends for this and > I don't recommend it for any life threatening activities.
But, I was able to bounce my weight using this bend in a foot loop affair and it did not slip or come undone. I doubt seriously that while it was loaded with my weight that I or another would have been able to cause it to spill. To me it is no more dangerous than any slipped knot that is going to see loading.
Perhaps I get favorable results due to the qualities of the ropes and cords I use.
I see it as no more insecure than the standard sheet bend once dressed and tightened. < My humble opinion, based on my own personal experience.
Heck, even a Zeppelin bend can be flailed loose.
I recommend anyone interested, to get a feel for the mechanics of how it works, to tie it and load it however you see fit and see for themselves.
SS369
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Hello roo,
I'll stand by that statement I made about the OP bend being secure, at least for me. I would not use it for rappelling because there are more secure bends for this and > I don't recommend it for any life threatening activities.
It's secure as long as you disregard all the modes by which it is horribly insecure? That is exactly the kind of muddled and flatly misleading message that is going to confuse and endanger casual observers.
I have a very non-exotic cord in front of me that bounces out of the bend in question almost immediately, even when tightened. Maybe you got the bend tighter in a different rope type, but tightening a knot becomes radically more difficult as rope diameter increases.
Let's set aside rope size and type for a moment. I don't know how you can dismiss the security issue of the bend falling to pieces if either or both of the free ends are so much as touched. The free ends get snagged, stepped on, and dragged on terrain in real life. This is an integral part of security. Even if you naively think the free ends will never see any force, you'd better hope no other person ever tries to tighten your bend for you, because most people tighten bends by pulling all four ends... an act that will eliminate what little security this bend ever possessed.
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I do not consider the Thief Knot "easy-to-tie" for the inexperienced knot tyer.
:)
Most who will tie it are somewhat experienced and very likely aware of its slippery nature.
Listen what "you" say : most of the people who is likely to tie the Thief knot are somewhat experienced, so they will not be killed. "I" say that ONLY people that are VERY experienced is likely to tie the symmetric sheet bend - and, moreover, some of them will not try to understand it, and so they will not be able to tie it :)... So, I say that, in contrast to the Thief knot, only a handful of very experienced people will ever tie this bend, and I an sure no one of them will be killed ... :)
Those with experience are also likely aware that it is unwise to use a "binding knot" as a bend.
I like this distinction, but I am not sure I know what is what... Please, elaborate it a little more. There are a number of knots that can be used in either way, I think...This is an interesting discussion by its own right. Have a look at the binder/bend presented at (1). Is it a bend or a binder ? This is an interesting discussion by its own right.
Thus, we have There are the "Reef Knot" or "Thief Knot" and not the "Reef Bend" or "Thief Bend".
It would be nice if that was the idea behind the selection of the names...but, most of the times, names have little to do with the essentisl characteristics of the knots, they serve as just labels, not descriptions, I am afraid. Is the fisherman knot NOT a bend ? :)
1) http://igkt.net/sm/index.php?topic=3656.msg21375#msg21375
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as rope diameter increases.
As rope diameter increases, it is getting far more easy to tie the knot correctly, so the result is a far more secure knot. :)
The issue with the ends is a real issue, of course, and if one is going to actually use this knot as a bend somewhere, I guess that, being an experienced knot tyer, he will be aware of this obvious fact...I have presented this bend as a simple yet difficult to tie bend - even difficult for experienced knot tiers, as I see now, may be because these people are accustomed to handle things the way they know for years, and they are not ready to try and understand something new...I have said that it is depending upon the knowledge and the dexterity of the knot tyer...and that it should better be compared with the ABoK#1406. Unfortunately, ABoK#1406 happens to be in the holy book, so it is a thing made by god, while this symmetric sheet bend is not, so it is, evidently, made by devil. Brrr... :)
When I say "secure", I only mean "does not slip as easy as other similar bends, tied on the same material", and when I say "strong", I only mean "it does not break as easy as other, similar bends, tied on the same material". Roo gives a more general meaning to 'knot security", and he may be right. If we include all factors that will determine the outcome of a knotting act, like the inexperience or ignorance of the knot tier, the possible disturbances caused by the environment, ( as the disturbance of the position of the tails roo mentions ), the possible change in the loading pattern, etc, then, of course THIS BEND IS NOT SECURE, NOT AT ALL ! Exactly the same can be said for ABoK#1406, and some other knots, marked in ABoK by the scull and crossed bones DANGER sign.
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It's secure as long as you disregard all the modes by which it is horribly insecure? That is exactly the kind of muddled and flatly misleading message that is going to confuse and endanger casual observers.
I have a very non-exotic cord in front of me that bounces out of the bend in question almost immediately, even when tightened. Maybe you got the bend tighter in a different rope type, but tightening a knot becomes radically more difficult as rope diameter increases.
Let's set aside rope size and type for a moment. I don't know how you can dismiss the security issue of the bend falling to pieces if either or both of the free ends are so much as touched. The free ends get snagged, stepped on, and dragged on terrain in real life. This is an integral part of security. Even if you naively think the free ends will never see any force, you'd better hope no other person ever tries to tighten your bend for you, because most people tighten bends by pulling all four ends... an act that will eliminate what little security this bend ever possessed.
Roo, I am am not advocating the use of this exploratory bend to anyone for anything and I have made it clear in two posts now that I don't recommend it for life endangering activities. I am part of a discussion here amongst interested knot tyers and naysayers about the workings of the knot in the original post. I posted that my own method of simple testing this bend disclosed a security (meaning that it did not slip and the connection remained intact) that I would not have thought it had, but it did.
I just now tied it again in 8mm rope( not all that exotic), tightened it up with a yank on both standing parts and then I kicked it and rolled it under my foot. It did not come undone.
So just touching, as you've indicated you can do causing it to explode, does not work for me. Perhaps I am naive in the magic arts.
As for anyone tightening "my bend" for me (!?). I think not.
Beware casual observers. Make sure that you become advanced knot tyers before you tie any knots.
SS
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This bend has lots of drawbacks, I can't believe it's even garnered the attention it has on this board. The average person is in MAJOR trouble if they come here and try to find an acceptable bend and run across this one. Please don't say the average person doesn't come here because I was that average person a while back but I've chosen to stick around and have learned virtually every knot that remotely interests me.
I'll say this, if I were to choose a bend to learn for the average person, it would be the Zeppelin Bend. The Zeppelin Bend is a heavy duty performer and checks off well on most of the criteria a keen eye looks for. It's not a fickle bend such as this one presented by xarax. This bend is terribly hard to tie, unloads at the smallest tug of it's WE's and these facets alone, make this a skull and cross bones bend. This bend would spill/unload in harsh, rugged and extreme working environments such as industrial work sites, military operations etc. The WE's scenario is a strange one too, even though a serious knot tier knows not to tamper with the WE's after the bend's set. Roo has exposed this bend as flakey at best.
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I can think of a practical use for this bend. Imagine you have two ropes. You want to jump down 5 stories into water. You want to slow your fall. You also want to bring at least one rope down into the water with you.
Here's a solution. You anchor one rope at the top where you are. You tie this bend in the OP to join the ropes. You tie the bend such that once tension hits this bend during your fall, the bend will operate to slow your fall. The bend slows your fall by NOT holding, but rather slipping with some friction. The bend comes apart as you near the water, and the lower rope comes down into the water with you.
This experiment could go horribly wrong if the bend actually holds! So, unfortunately, this bend may also be a bad choice for what it does best.
(That's an idea for a new thread: What are practical applications in which one would intentionally want a knot to slip?)
SS369, may I suggest you experiment with this rope in more types of rope? Maybe try less expensive ropes that are more likely to be used in everyday tasks outside of climbing. It seems like you're playing a little bit of the devil's advocate here. That's useful to have another perspective, but it also makes you sound like you're a bit too far out there.
BOTTOM LINE: I may like to use this bend in an application where I intentionally want the bend to slip, but never in an application where I want the bend to hold securely.
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I'll say this, if I were to choose a bend to learn for the average person, it would be the Zeppelin Bend.
We agree on something ! :)
This bend would spill/unload in harsh...environments such as .. military operations
Ooos ! Another advantage of this bend I forgot to mention ! :)
Roo has exposed this bend as flakey at best.
That was the nail ion the coffin of this bend, indeed ! :)
My dear TMCD, you had also forgotten - or perhaps "glossed over" (roo s expression) :) - to mention the same things, when we were talking about the ABoK#1406, remember ? ( the ABoK#1406 that, evidently but unfortunatelly, happens to be IN the ABoK... :)
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The bend slows your fall by NOT holding, but rather slipping with some friction...
I may like to use this bend in an application where I intentionally want the bend to slip, but never in an application where I want the bend to hold securely.
The bend will hold very well, I am afraid, and you will break your spinal chord ! :) This bend does not slip, because it is based upon a mechansm that uses shear forces ; the tails are squeezed hard by segments of rope perpendicular to them, segments that bite the tails hard, and do not let them slip.
Before you jumb, spend some time, please, to read my previous, extensive posts, and try to see if I have any point that you just ddnt get. Also, I would be glad if you actually make some tests ( = experiments) before you put your theory and your back on the line, like the ones I have made...because we all want you in one piece here ! :) :)
P.S. As I have said many times, I do not recomend this bend to people that had never understood or tied it correctly, and so they believe it slips. Moreover, I now tend to believe that this simple bend is like a simple mathematical theorem : one should use it only iff he has understood its logic, but also one could use it only iff he has appreciated its beauty.
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It is the resistance of this pivot to shear forces, that ...
...Is no more "shear" than that of most(?) other knots,
I use this opportunity to show another interesting bend (see the attached picture),
that can be used when we want to connect two pieces of rope in a way that will allow
us to disconnect them easily, and then repeat the same cycle many times.
Yes, joining eyes with such inter-reeving is a nice solution;
I've played around with this in the same way --i.e., using
the eyeknots' tails--, and by using a separate rope for the
reeving. (IIRC, someone published something like this in KM
many moons ago, and that inspired my search, later.)
BUT, trying this with some shopping-bag poly cord (the cheap
things put in clothing-store shopping bags, braided), I've had
the joint pull apart on me enough to lead me to want some
more reeving for any serious work. --making a "square" pass
with each tail (i.e., a turn around the other eye's legs) and
re-tucking should suffice, and double the diameters in compression.
Now, this bend works exactly in the same way as the Zeppelin bend, ...
Actually, if the zeppelin is left a bit loose, there will be more
tension on the tails than in knots where those surrounding
bights/turns are interlocked (compressing the tails within);
this is readily seen in the sheet bend as it shifts under load
(i.e., the "same-side" (tails/SParts) version; the opposite-side
version remains more *square*, and seems less secure).
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I do not consider the Thief Knot "easy-to-tie" for the inexperienced knot tyer.
No, it takes some care in formation, unlike the lookalike
squaREef knot ; its "slippery nature" should be pretty quickly
apparent, upon trying to set the knot!
Those with experience are also likely aware that it is unwise to use a "binding knot" as a bend.
The thief isn't a binder, for sure.
Thus, we have the "Reef Knot" or "Thief Knot" and not the "Reef Bend" or "Thief Bend".
Hardly. We have "fisherman's knot" and that's one of the most
common end-2-end knots around. Let's not pretend that Ashley's
wish for "bend" use was or is as he desired. --or that the supposed
dangers of the reef are a fact : that knot was for decades part
of some marine requirements, though I've heard rumor that it was
observed for a test and ignored in practice. I've not heard actual
reports of its supposed dangers (unlike, e.g., many reports of the
problem of bowlines loosening & failing).
Let's set aside rope size and type for a moment.
I don't know how you can dismiss the security issue of the bend falling to pieces
if either or both of the free ends are so much as touched.
The free ends get snagged, stepped on, and dragged on terrain in real life
Or, let's not : it might be in some case of hawser-joining that
such an easily untied and material-efficient joint is desired,
for some momentary use (hence the desire to un-tie). All
this fear of "falling to pieces ..." on mischief done behind one's
back, so to speak, is pretty much beside the point in such a
case (beyond SS369's rejoinder about how much more durable
his knots are than yours --maybe it's a question of the tyer?).
Now, I doubt that the carrick bend will lose ground to this.
Also, note that this knot is --as is the thief and it's more secure
cousin, the fig.8-- *ambidextrous* (er, both-handed) : for
laid rope, this means that there is a form-wise asymmetry to
the knot; a weaker & stronger side, likely --from the one SPart
turning with, and the other against, the lay of the rope.
(In braided rope we may not care.)
Finally, as for jumping 5 stories and expecting some frictional
magic out of a slipping knot, well, you must be working with
some strange physics on that.
--dl*
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double the diameters in compression.
You mean, in resisting shear forces, double the rope-made pivot s diameter, double the number of diameters...So, I think that those kinds of bends should be tied only on relatively stiff, relatively incompressible material....Perhaps that is a part of the problem some people have when they try to tie the symmetric sheet bend ? ( I have not tried it with laid rope, to see if there are any noticable differences between S and Z ropes...I do not doubt that there will be some differences indeed, but I can not even imagine if it woiuld be beneficial for this bend to have its tails resist to the further twisting - induced by the "cogging" effects -, or not ! :))
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I can think of a practical use for this bend. Imagine you have two ropes. You want to jump down 5 stories into water. You want to slow your fall. You also want to bring at least one rope down into the water with you.
Here's a solution. You anchor one rope at the top where you are. You tie this bend in the OP to join the ropes. You tie the bend such that once tension hits this bend during your fall, the bend will operate to slow your fall. The bend slows your fall by NOT holding, but rather slipping with some friction. The bend comes apart as you near the water, and the lower rope comes down into the water with you.
This experiment could go horribly wrong if the bend actually holds! So, unfortunately, this bend may also be a bad choice for what it does best.
(That's an idea for a new thread: What are practical applications in which one would intentionally want a knot to slip?)
SS369, may I suggest you experiment with this rope in more types of rope? Maybe try less expensive ropes that are more likely to be used in everyday tasks outside of climbing. It seems like you're playing a little bit of the devil's advocate here. That's useful to have another perspective, but it also makes you sound like you're a bit too far out there.
BOTTOM LINE: I may like to use this bend in an application where I intentionally want the bend to slip, but never in an application where I want the bend to hold securely.
SS369, may I suggest you experiment with this rope in more types of rope? Maybe try less expensive ropes that are more likely to be used in everyday tasks outside of climbing. It seems like you're playing a little bit of the devil's advocate here. That's useful to have another perspective, but it also makes you sound like you're a bit too far out there.
Hello knot4u, I enjoyed your little story, but it is not anywhere near the case in my experience with this bend.
In my first post in this thread I wrote that I have tried this affair in cords and ropes from 3mm - 13mm diameters. I failed to mention the material and compositions, sorry. The ropes are varied in that regard, laid, double braided and kernmantle in cotton, poly( different mixes), nylon, etc. Since that writing I have tried repeatedly using more "exotic" materials such as stainless steel 1/16 inch aircraft twisted cable, 1/2 inch (twisted) manila, leather lace, tarred netting cord, hemp craft cord, 550 paracord, 1.4mm venetian blind cord, 10 lbs. monofilament fishing line and 1/4 inch chain. To date the only lines that gave me trouble tying were the chain and monofilament and that was in the tying.
Once tensioned they all held except for the mono and cheap cotton #72 twisted utility line that broke when I stressed it. I did not tension to breakage the leather or the hemp craft cord. The others I didn't bother to try breaking either.
I suspect that you are having a tough time tying this correctly and I don't recommend that you use this to ensure your safety when you "jump down 5 stories into water". You may do well to just jump with both pieces of rope however inexpensive they are.
Seriously now, I am not advocating the use of this exploratory bend for anything at all. I have only evaluated it for myself and found it to be as I have written. I am surprised that some have found it to be otherwise. I find it to hold well under tension and interesting that the simplicity of it works.
I suggest that the "average person" read the thread (including the opinions of the safety or lack of it), tie the bend, evaluate it for what it may be worth to them and do with it as They choose. I am under the impression that some people, members included, are here to learn things (and read some interesting ditties), discuss things and have a good time. I hope you are.
Bring to the thread your experience with this and other knots. Be sure to include a situation that you would like a bend to slip and perhaps we can help figure out what may be the best for that application.
As for being a devil's advocate, nah, not truly.
Sincerely.
SS
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I just now tied it again in 8mm rope( not all that exotic), tightened it up with a yank on both standing parts and then I kicked it and rolled it under my foot. It did not come undone.
So just touching, as you've indicated you can do causing it to explode, does not work for me. Perhaps I am naive in the magic arts.
As for anyone tightening "my bend" for me (!?). I think not.
I didn't ask you to step on the knot or kick it. Step on a free end while pulling! You keep avoiding this obvious mode of catastrophic failure, and pretending it's a non-issue, as shown by your last line that indicates your willful blindness to this issue.
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All this fear of "falling to pieces ..." on mischief done behind one's
back, so to speak, is pretty much beside the point in such a
case
That "mischief" might just be someone trying to help. And the complete degradation of the bend due to mild forces on the free ends need not happen "behind one's back" unless you think every snag, dragging, footstep and whip of a free end around an object occurs behind your back. It's not a minor point, or beside the point. It's the pin of this grenade.
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I have tried repeatedly using more "exotic" materials such as stainless steel 1/16 inch aircraft twisted cable
I believe that, if this bend will ever be used for a practical purpose, it would be most probably used on wire ropes - or on very thick, large diameter solid or double braided ropes. However, I myself have nor the tools and instruments, neither the knowledge and experience to perform tests with such "exotic" - but ordinary, every day life s nevertheless - materials. I am sure that the evil impostor of this bend, the "fig. 8 knot for cables and wires" (1) is, and would be very easily proven to be, inferior, by far, to the symmetric sheet bend... So, if the former is well known and utilized by the industry, why would the later remain totally ignored ?
Now, the point made by Dan Lehman about this bend being (very ?) sensitive to the helicity/handedness of the laid ropes ( S or Z ), would also apply to the wire ropes. I fact, with common two layer stranded wire ropes, the situation is even more complicated, as we have ordinary lay ropes and lang lay ropes...I have no clue how exactly, and how much, the particular helicity/handedness of a laid rope would influence the security and strength of a symmetric sheet bend tied on it, so the question about the two layer stranded wire ropes is rocket science for me... :)
1) http://igkt.net/sm/index.php?topic=3716.msg21487#msg21487
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All this fear of "falling to pieces ..." on mischief done behind one's
back, so to speak, is pretty much beside the point in such a
case
That "mischief" might just be someone trying to help.
And the complete degradation of the bend due to mild forces
on the free ends need not happen "behind one's back" unless you
think every snag, dragging, footstep and whip of a free end around
an object occurs behind your back.
It's not a minor point, or beside the point. It's the pin of this grenade.
I think you need to get out of your armchair and see some
real rope at work. The scenario I hypothesized has to do with
stout rope in use, which doesn't brook of any "mild forces"
interruption. E.g., I just pulley loaded (hmmm, 100# force?)
[per Roo's note of omission : 1/4" ropes, laid + braided]
a round sling joined with this knot & the zeppelin; now, I've
tied 25# barbell wgt. to the tail of the upper cord --which I
took to be the more vulnerable one--, and even with a small
drop of this load, the crusty old knotted rope holds; a few
more, bigger drops, and now the half-hitch form is pulled
out of position. Going to the other tail seems more resistant,
but I don't want to attribute that to orientation vs. the ropes.
Note that in these tests only the tied-above SPart is under
tension, the lower SPart is free, and its tail is loaded, or
only the other rope's tail (& SPart) is.
Now, what I mused I think would see a carrick bend put in,
and the OP knot has an uphill battle to supplant that; but it
might, per some users.
--dl*
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It's the pin of this grenade.
:) I like this metaphor. Actually, I think that, if this bend is really very easily untied - when one pulls the free end of one link towards the standing end of the other -, then this is a property of great practical importance ! A bend that can be untied easily, even while it is heavily loaded, is a very useful bend indeed. Roo, you are trying to persuade the members of this forum that this might be a practical bend after all, while I proposed to move the thread to our new 'Knotting concepts and explorations' forum ! :) I can even imagine some hunting and military applications based on this property (traps, etc.), so even TMCD would be satisfied. Brrr.... :)
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I think you need to get out of your armchair and see some
real rope at work.
Here we go again. Nobody in this forum does real rope work, except Dan. ::)
The scenario I hypothesized has to do with
stout rope in use, which doesn't brook of any "mild forces"
interruption. E.g., I just pulley loaded (hmmm, 100# force?)
a round sling joined with this knot & the zeppelin; now, I've
tied 25# barbell wgt. to the tail of the upper cord --which I
took to be the more vulnerable one--, and even with a small
drop of this load, the crusty old knotted rope holds; a few
more, bigger drops, and now the half-hitch form is pulled
out of position. Going to the other tail seems more resistant,
but I don't want to attribute that to orientation vs. the ropes.
Note that in these tests only the tied-above SPart is under
tension, the lower SPart is free, and its tail is loaded, or
only the other rope's tail (& SPart) is.
So what size is this rope that endured a 100 lb initial loading (if I'm deciphering you correctly)? Do you really think that is representative of common human strength setting of a bend in either medium or larger-size rope?
Either way, 100 lbs of intial load might be a great deal of initial strain for a tiny rope, or a negligible inital strain on a large rope. I find that I can easily destroy the form of the bend with forces on the free end in the high ounces to low pounds range after a typical setting load in small rope. I estimate it's closer to the ounces range.
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I can think of a practical use for this bend. Imagine you have two ropes. You want to jump down 5 stories into water. You want to slow your fall. You also want to bring at least one rope down into the water with you.
Here's a solution. You anchor one rope at the top where you are. You tie this bend in the OP to join the ropes. You tie the bend such that once tension hits this bend during your fall, the bend will operate to slow your fall. The bend slows your fall by NOT holding, but rather slipping with some friction. The bend comes apart as you near the water, and the lower rope comes down into the water with you.
This experiment could go horribly wrong if the bend actually holds! So, unfortunately, this bend may also be a bad choice for what it does best.
(That's an idea for a new thread: What are practical applications in which one would intentionally want a knot to slip?)
SS369, may I suggest you experiment with this rope in more types of rope? Maybe try less expensive ropes that are more likely to be used in everyday tasks outside of climbing. It seems like you're playing a little bit of the devil's advocate here. That's useful to have another perspective, but it also makes you sound like you're a bit too far out there.
BOTTOM LINE: I may like to use this bend in an application where I intentionally want the bend to slip, but never in an application where I want the bend to hold securely.
Hi K4u,
The point with this knot is that it does NOT slip - it is completely secure in the form presented in the op.
However, it is one of three configurations this knot can be dressed into, the other two both cog easily.
And this is another point - they do not slip, they cog, and with this knot it is rotational cogging as well as linear cogging. Two things lead from this - first - both sides of the knot run (cog) through simultaneously, so if one end runs out first, the whole knot falls apart, irrespective of how long your descender cord is. The second issue is that rotational cogging does as its name implies, it rotates the cordage, i.e. it twists it. If this twisting gets too extreme the cord will twist up and lock its progress through the knot, effectively blocking your descent...
If the cordage was long enough to reach the ground, I would use a knot I would be prepared to put my life on - Carrick bend etc. The point being made repeatedly is that this knot is dangerous. I have to fully agree with Roo, there are so many ways this knot could be converted into a cogging form, it should never be contemplated for anything other than a thought exercise on 'how knots work.
Derek
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three configurations this knot can be dressed into.
there are so many ways this knot could be converted into a cogging form
Actually, there are many more incorrect ways one can dress this knot, but I will not enumerate them here. That is why the knot is difficult to tie, because the possible errors are many ! However, there is ONE way that is 100% correct, is nt it that so ? :) ONE correct way that can lead to one secure knot - i.e., a knot that that does not slip- is enough for me. :)
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I just now tied it again in 8mm rope( not all that exotic), tightened it up with a yank on both standing parts and then I kicked it and rolled it under my foot. It did not come undone.
So just touching, as you've indicated you can do causing it to explode, does not work for me. Perhaps I am naive in the magic arts.
As for anyone tightening "my bend" for me (!?). I think not.
I didn't ask you to step on the knot or kick it. Step on a free end while pulling! You keep avoiding this obvious mode of catastrophic failure, and pretending it's a non-issue, as shown by your last line that indicates your willful blindness to this issue.
roo
Willful blindness is a bit dramatic in this particular post, don't you think? You're being a bit specious with me considering I do not give advise to use this bend. I believe you are making a exceedingly large issue of it by your continuing to pound away at the keys on it. It has been said already.
I have written that I loaded this bend with my own weight(175 lbs.), bounced on it using a foot loop affair and it held. The tails were approx. 3 inches long. I noticed no slippage and it certainly did not come undone. I believe this test, simple as it is, imparts more force on the rope than the method you've espoused here a few times (rods, foot and knees).
I have just now repeated the simple foot loop test and while suspended I gave one tail (longer now so I could wrap it around my hand) a tug and I stayed above ground.
I think that there a few bends and a few "secure" knots as well that fit your grenade pin pulling metaphor.
I kicked and rolled of my own volition. Sort of didn't think I needed clearance on that.
I like the fact that it can be spilled relatively with some ease when its load is released, just the same as the bell ringer loop can once you're done with, let's say, a truckers hitch use. Both hold while under loading.
I'll reiterate my experience. It holds loaded in the ropes and cords I used to evaluate it. It held in cords I would not use it with. I would not be using it for life endangering/rescue work! And it is an exploratory knot for the use of discussion.
As for using rope for real work (though that statement was aimed at Dan), I do use rope for work perhaps a bit more than most here. Yes, a presumption, but I feel justified.
As for my willful blindness, I generally do not have others doing my rope work or tie the knots I will be using unless I feel confident they know how and have shown me so. Occasionally I even teach someone a knot or two.
Would you feel much better if this thread was moved to the Explorations Board?
SS
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And is this knot so difficult to tie??
If you can tie a sheet bend, do so relatively loose . Then take the wend of the uncrossed bight and insert it into the opening between the uncrossed bight's sp and the crossed bight where they are close, then grab the two sp's, nothing else, and give them a yank.
It is no more difficult than the sheet bend.
SS
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Tie a sheet bend, one that has the WE's on the same side, and snug up it a bit. Then take the non-crossed bight's Working End and cross it over it's own Standing Part and insert it down through the opening between the SP and the other's bight. Pull slowly and final tighten.
I'm able to make the knot hold in 2mm polyester with this tying method. I'm not able to make the knot slip one bit by using arm power.
By pulling the working ends, I will hear a "click" and the knot capsizes into a form where I can pull the knot apart by pulling the standing parts.
As for a pin of the grenade, I would rather use a slipped sheet bend. If I have bulky working ends (example: tied stopper knots), then the knot can't be pulled totally apart. The sheet bend is also tried and tested for different sized diameters, different types of materials, one tuck simpler to tie, harder to tie wrong and the "pin of the grenade" is optional.
I would not be using it for life endangering/rescue work!
If you would not be using the knot for life endangering work, you should probably not use it where there's something of value involved either. Why risking damage on your car because of a failing knot, when you can use a perfectly safe knot instead?
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Willful blindness is a bit dramatic in this particular post, don't you think? You're being a bit specious with me considering I do not give advise to use this bend. I believe you are making a exceedingly large issue of it by your continuing to pound away at the keys on it. It has been said already.
You keep wrongly calling it secure despite several people noting what happens to the bend when a free end (working end) sees force, by snagging for example.
I have written that I loaded this bend with my own weight(175 lbs.), bounced on it using a foot loop affair and it held.
Why do you keep going back to this while ignoring the easiest mode of failure? It sure looks like willful blindness so you don't have to retract your security claim.
I have just now repeated the simple foot loop test and while suspended I gave one tail (longer now so I could wrap it around my hand) a tug and I stayed above ground.
ibid. You know the easier mode of failure. Pull one standing part while pulling a tail. When the parent line tension resumes or starts, say goodbye.
I kicked and rolled of my own volition. Sort of didn't think I needed clearance on that.
More avoidance of the elephant in the room.
I like the fact that it can be spilled relatively with some ease when its load is released, just the same as the bell ringer loop can once you're done with, let's say, a truckers hitch use. Both hold while under loading.
And nobody uses a bell-ringers loop like a bend or describes it as a secure bend.
I would not be using it for life endangering/rescue work!
But you keep insisting that it is secure.
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I've tied it in cordage with different sized diameters and different materials. The dark cordage is made of polypropylene and is thicker than the white cordage. The white cordage is polyester.
It seems to hold well, but further testing is needed.
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I've tied it in cordage with different sized diameters and different materials.
I hope not as soft and of such a small diameter as the ones shown in your pictures ! :) To clearly see what you are doing, and to be able to handle the strands with the care and the precision required, I suggest that you start from rather stiff, incompresseble materials, with LARGE diameters ( not much thiner than your fingers... :)). When you will be accustomed to such ropes, then you can proceed and try to tie it with ropes of smaller diameter. Anyway, as I have said many times, this bend is obviously begging for large diameters, and hard, solid ( not hollow braided, for example ) ropes.( My tests were mostly done with 9 -12.5 mm climbing kernmantle ropes, and 1/2 inch nylon solid braid rope. Static kermantle climbing ropes, being so stiff and able to retain their round cross section when they are subject to shear forces, are probably the easier and safer material which one can use, when he starts learning this bend.
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Xarax,
Is there anyway you could post a video of your tying method for this particular bend because I can't seem to consistently get it set properly. I think it's a good looking bend but the security issues AND tying issues are a concern, a video would be appreciated.
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The sheet bend is also tried and tested for different sized diameters, different types of materials, one tuck simpler to tie [and] harder to tie wrong
All very true...but does the common Sheet bend slip LESS than this bend ? I think not, because the tails there are not as effectively interrupted, in their effort to slip and free themselves out of the knot s nub, as it happens in this bend. Here we have both tails squeezed in between two strands of rope, and, on top of that, each tail is most effectively squeezed by a rope strand at a right angle (perpendicular) to it... That is, we have strands that bite other strands hard, and so make deep 'dents" in the skin of the tails, that penetrate deep into their body - and those dents act as obstacles that block/prevent slippage.
Does the common Sheet bend is stronger a knot than this bend ? I think not, because the common Sheet bend is a highly asymetric bend, and one of the two links will be loaded more and will break first, long before the other reaches the same limit. Symmetric bends are better suited to equalize the forces and achieve higher breaking strengths than asymmetric ones.
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Is there anyway you could post a video of your tying method for this particular bend
Oh, my dear TMCD, my method is dumb! ( I can not even tie a f... Sheet bend quickly enough !) You have to ask SS369 to do this, ( I already did ... :)), because his method is clever - and I see that Hrungrir already uses it, and has good results....Although I think that the tying method is of much importance here, I also strongly believe that the problem people have has more to do with an inadequate understanding of the mechanism that prevents the tails to slip out of the knot s nub. Also, it is recommended that you better start from a stiff, hard, solid core rope, with as large a diameter as you can handle ! :) ( It also depends upon the size of your fingers and your corrective lenses... :)
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I've tied it in cordage with different sized diameters and different materials.
I hope not as soft and of such a small diameter as the ones shown in your pictures ! :) To clearly see what you are doing, and to be able to handle the strands with the care and the precision required, I suggest that you start from rather stiff, incompresseble materials, with LARGE diameters ( not much thiner than your fingers... :))
Hei xarax!
By using the tying method of SS369, I was able to tie your knot in 2mm polyester in my very first attempt. By using his tying method, the working ends fall correctly in place when pulling the standing parts. The bend seems to hold well in this form.
When it comes to diameters, the cordage in the picture is the thickest I have at hand right now. I'm not sure what the diameter is, but you get an idea when you see my fingers. The polyester is somewhat soft yes, but you won't find cordage which is much stiffer than polypropylene.
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Is there anyway you could post a video of your tying method for this particular bend because I can't seem to consistently get it set properly.
I don't have a video, but I have a picture of the tying method.
I tie a sheet bend. The white cordage is parallell and the dark cordage is making the half hitch.
Then I retuck the working end of the white cordage as described by SS369 and shown in the picture. Tighten the knot by pulling the standing parts only.
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Willful blindness is a bit dramatic in this particular post, don't you think? You're being a bit specious with me considering I do not give advise to use this bend. I believe you are making a exceedingly large issue of it by your continuing to pound away at the keys on it. It has been said already.
You keep wrongly calling it secure despite several people noting what happens to the bend when a free end (working end) sees force, by snagging for example.
I have written that I loaded this bend with my own weight(175 lbs.), bounced on it using a foot loop affair and it held.
Why do you keep going back to this while ignoring the easiest mode of failure? It sure looks like willful blindness so you don't have to retract your security claim.
I have just now repeated the simple foot loop test and while suspended I gave one tail (longer now so I could wrap it around my hand) a tug and I stayed above ground.
ibid. You know the easier mode of failure. Pull one standing part while pulling a tail. When the parent line tension resumes or starts, say goodbye.
I kicked and rolled of my own volition. Sort of didn't think I needed clearance on that.
More avoidance of the elephant in the room.
I like the fact that it can be spilled relatively with some ease when its load is released, just the same as the bell ringer loop can once you're done with, let's say, a truckers hitch use. Both hold while under loading.
And nobody uses a bell-ringers loop like a bend or describes it as a secure bend.
I would not be using it for life endangering/rescue work!
But you keep insisting that it is secure.
roo, I don't know why you are being so semantically inclined here. Yes, I said the knot was secure and I described my method of arriving at that conclusion. No, it did not take into account every possible scenario that could cause it to spill. That is one of the things a forum discourse can be helpful with.
Care in rope work is a must and always will be and you can load this page with all manner of what ifs and whatnots, so if you drag and snag during your testing that is fine. I did not, though I did do a second test as I wrote and tried to pull one free end (working end) to cause it to spill. It didn't.
You are taking one-liners and making a case where there is no case to make. I said that this knot was secure in My tests. Get it through your head that I have no intention nor am I recommending this to anyone for use in anyway. Capishe??
With your attempt at bullying here to force an admission from me I believe it is you who are behaving like the elephant in the room.
The analogy of the bell ringer loop was to indicate, not to you only, that it can be a helpful thing that one could easily untie a bend such as this. Not that I am suggesting that the BRL be used as a bend. But there may be some-such a thing in the future.
The original poster and another forum member has indicated that he has tied it and found it to hold and not slip one bit using his arm power.
I still think that in the scenario of my test/evaluation that my statement holds.
No, I won't be using it for life saving or anything like that, there are better knots, but I have said this repeatedly for the sake of the reader who may misinterpret anything. Or a member who reads only what he wants to so he can bully and argue.
The whole thing has been blown out of proportion, by you, considering that from the get-go this has been a discussion about the workings of the offered bend. If you didn't take the stance you do most often there might be more contributors to these discussions. And they might learn something useful.
If you want to be right, you're right, but I am not wrong.
Please consider no more clever rejoinders and join the discussion in the way it was meant to be because you are seriously derailing the intent of the topic.
If you have anything else to say to me personally, I would appreciate that you do so by the personal message option. Thank you.
SS
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you won't find cordage which is much stiffer than polypropylene.
That is why I have recommended a kermantle climbing rope...
Also, I suspect that this bend is sensitive to the helicity of the laid rope, in a quite subtle way, with possible consequences I can not predict... It would behave somewhat differently if tied with an S or with a Z rope - but I myself do not know yet which would be more secure and/or strong, and why...
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Thank you Hrungnir for the picture and the better way of describing "my" method. ;-) After reading my own post describing how I did it, it made sense to me and I hoped it would be useful for someone else. Sometimes it goes like that with verbal descriptions.
And yes you may be correct that one could use a better knot to save their car or truck from damage, but for me I can not think of a time when I have had to use a bend during that kind of activity. Just my experience.
SS
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No, it did not take into account every possible scenario that could cause it to spill.
This is some progress.
Acknowledging these scenarios as security problems will help others from learning them the hard way.
The second, less obvious security problem arises from slack shaking that causes looseness that can again cause the bend to assume its free-rolling form.
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The analogy of the bell ringer loop was to indicate... that it can be a helpful thing that one could easily untie a bend such as this.
the BRL be used as a bend. But there may be some-such a thing in the future.
Perhaps the bend shown in (1), and a reply to it in (2) , were somehow lost in the exchange of opinions- or of what else is exchanged here :) . Have a look at it. It is a secure bend, it can be tied and untied easily, and also has an additional advantage, that might be proven to be useful/practical : One can keep the slipped overhand knots tied on the ends of the two ropes, and hook and then un-hook them, the one with the other, using their tails as pivots. In shorts, another rope-made hinge, just as the Zeppelin bend - but not as economical in material use. I think that it works in a way similar to the symmetric Sheet bend ( or "ABoK#1406 b', if you like... ), that is, it is depending upon the resistance of the tails - that, taken together, play the role of a rope-made pivot - to the shear forces, induced on them by the tension of the perpendicularly placed bights.
1. http://igkt.net/sm/index.php?topic=3716.msg21527#msg21527
2. http://igkt.net/sm/index.php?topic=3716.msg21543#msg21543
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This thread proves this bend is not simple.
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this bend is not simple.
We enter into a very complex subject here, knot4u ! :) What is "simplicity' is debatable, and it is not a simple matter at all, that is for sure ... I use the word in a restricted, quantitative sense, that has to do with the number of elements , and the number of relations between elements, an entity has. You know Newton universal gravitation equation, Maxwell s equations, ( in their antisymmetric tensor form), Einstein gravitational field equations... They are "simple", in that they relate a few quantities with a few relations, yet, in a broader sense they are not simple, not at all !
We can easily say that a tetrahedron or a cube, for example, are the simpler Archimedes polyhedra. However, our evaluation might depend upon the machine and the language we use to describe them. We can actually count simplicity, by counting the number of bits and bytes a particular computer, with a particular program that is able to describe a thing, will use. (Computational complexity : A relevant web book, at (1) , and a simple article, at (2)). But what happens with another computer, and with another compute language ? In some computers and some computer languages a thing can be described with a shorter, more economical in bits and bytes program than another thing, so we can argue that the former is simpler than the later... but, in some others, the order of simplicity count can well be reversed ! And the matter can be vastly more complicated than that, because brains evolved to understand the difference between a cow and a tiger, not between the symmetric sheet bend and the ABoK#1406 ! For a cat, a mouse is a much simpler thing than either a tetrahedron or a cube, that is for sure. :)
In the field of knots, to count complexity in an objective way, should we include only the geometrical elements of a knot, or also the steps - tucks or whatelse -, we have to follow to tie this knot ? Should we count only the 3D geometrical elements of the tied knot, or also the physical mechanisms needed to keep this 3D machine in a static equilibrium ? A knot simple in geometrical elements count, but complex in physical mechanisms count, is it a simple or a complex knot ? You tell me... :) At the end of the day, what counts are not semantics, but our lives... and lives, being so short, should better be interesting to live. This bend is an interesting thing, and when we learn interesting things, we feel we live longer... :)
1) http://www.cs.princeton.edu/theory/complexity/bookWebNov06.pdf
2) http://pespmc1.vub.ac.be/COMPLEXI.html
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The second, less obvious security problem arises from slack shaking that causes looseness
Could you plese elaborate on this a little more ? ( - because I think I do not understand this statement ). You mean the removal of slack during the dressing and tightening phase, or the possible generation of slack in a taut knot ? You mean the slack of the ends, or of the bights ? Is there such a "slack shaking" if the bend is kept tightened under constant load ?
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Hi Xarax,
I just noticed that if you start out with my "small fancy bend" and pull out each working end one "step" (I don't know the technical term for a rope crossing), then it becomes a stable version of your symmetric sheet bend. But if the WEs are shifted to a different orientation, then it unravels like a thief.
Mike
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Thank you Mike,
...if you start out with my "small fancy bend" and pull out each working end one "step" then it becomes a stable version of your symmetric sheet bend.
Right. (I had not noticed that....) So, this points to yet another, (somehow indirect...) way to tie this bend ! :)
What a difference a tuck can make ! :)
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Ashley shows a number of "Single Carrick" mats, as he calls them, but not the mat upon which the symmetric sheet bend is based ... and I really wonder why. His ABoK#1440 mat is only a tuck different - in fact, it is quite easy to confuse those two ( I myself have confused them in my previous post, which I have edited now). Based upon this superficial resemblance, I call the mat that leads to the symmetric sheet bend "ABoK#1440 b".
Now, I have discovered that we can tie the symmetric sheet bend starting from this mat, the ABoK#1440 b, - and not tying the Thief knot or the Sheet bend first, and only afterwards, by slight modifications of those bends, arrive at the symmetric sheet bend. I have tried this approach because I think we do not pay due respect to this genuine, elementary bend, if we tie it by first tying some other knot- similarly looking but in fact do different, as the Thief knot or the Sheet bend. ( And because I was not able to follow the SS369 clever method... :)) So, I tied the ABoK#1440 b mat with kermantle ropes (as shown in the picture - notice that the openings are about one rope diameter wide), I closed my eyes, and then I start pulling the standing ends, slowly. Abra Cadabra ! The mat closed into a perfectly symmetric symmetric sheet bend, without consuming much of its tails. Some other time I had to hold the tails in place, by my thumb and index fingers, while I was holding the standing ends by my other fingers. I have discovered that the kermantle material has a kind of "memory', and if one keep tying and untying the bend with the same ends of the same ropes, these ends 'remember' , in some sense, the final form they had in the previous tying. So, it is easy to tie the bend again and again, starting from the ABoK#1440 b mat, and just pulling the standing ends, without even holding the tails in place.
I take the liberty to ask the other members of the forum to try the same procedure, with the materials they use. I have no doubt that the method will not work with softer materials, and it will confront the peculiarities of the twisted strands of the laid rope. However, it would be interesting if it works with other materials than stiff kernantle- and I guess/hope it will work also for wire rope.
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As far as the OP knot is concerned, to me at least, it does not matter what knot you tie to get to the end result because with other knots you will encounter equivalent tying along the way. I have tied it as the Carrick mat and as an additionally tucked Sheet bend, both end up as the same pre-tightened configuration. Also, I do not feel there is a need to tighten slowly by pulling the SP's, in fact I have repetitively consistent results in the "exotic" and not at all exotic cords and ropes by just yanking them swiftly apart.
And this does work with wire rope (1/16 inch) as I have indicated in a previous post and remains steadfastly intact under tension.
SS
Edited due to someone-who-sleeps-while-I-don't-s edit. ;-)
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the Ashley drawing is not the same as what is being tied in the photograph.
My dear SS369, we live in different continents, so I am sleeping while you are not ! :) The picture of the mat of the symmetric sheet bend I posted was correct - but it is based upon the mat I now call "ABoK#1440 b" - and not on the original ABoK#1440 ( as you rightly spotted ) ( I have edited my previous post, and, because I lost the original text somewhere, I had to re-write it from the beginning...Sorry, have another look at it, please)
My point is that we can start from the "ABoK#1440 b" Single Garrick mat, and tie the symmetric sheet bend easily, without having to hold the tails not to slip while we pull the standing ends, iff we tie it with the same ropes and the same ends again and again, in a stiff material. It seems that some stiff materials "remember" the form they had in their previous loading -may be because they are temporarily deformed in some way - and so they are easily, almost automatically driven to the same form they had taken previously. Had you noticed anything like this, with the plethora of materials you use ?
P.S. The ABoK#1440 "Single Carrick" mat is one tuck different from the symmetric sheet bend s mat, the "ABoK#1440 b"- so it is no wonder that it leads to the Sheet bend - which is one tuck different from its symmetric cousin.
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E.g., I just pulley loaded (hmmm, 100# force?)
[ in roughly 1/4" (6mm) laid + braided cords ]
a round sling joined with this knot & the zeppelin; now, I've
tied 25# barbell wgt. to the tail of the upper cord --which I
took to be the more vulnerable one--, and even with a small
drop of this load, the crusty old knotted rope holds; a few
more, bigger drops, and now the half-hitch form is pulled
out of position. Going to the other tail seems more resistant,
but I don't want to attribute that to orientation vs. the ropes.
Note that in these tests only the tied-above SPart is under
tension, the lower SPart is free, and its tail is loaded, or
only the other rope's tail (& SPart) is.
So what size is this rope that endured a 100 lb initial loading
(if I'm deciphering you correctly)? Do you really think that is
representative of common human strength setting of a bend
in either medium or larger-size rope?
Touche' . Trying the knot in 3/4" laid ropes (PP + Poly-Dac),
the exercise shows Roo's point --manual setting doesn't make
much difference to these particular not-so-flexible ropes. Now,
it might be that some setting assistance is available in a device.
Or, maybe some knot-holding device is used (tape, seizing).
Again, I'm reaching for some use in which the knot's appeal
is (a) efficiency of material, (b) simplicity of tying (yes, with
some learning of setting/dressing), (c) relative strength (this
remains to be seen; I think there are issues that affect ...),
and (d) ease of untying (by hauling on ends, to capsize-loosen).
And against the better-known carrick bend, I think there's
an uphill battle.
Re (c), two issues --perhaps at times connected-- are the
*ambidextrous* nature (both-handed; which the Fig.8 has, too)
of the knot, and the potential for *race conditions* to lead
to imbalance in loaded geometry --i.e., one SPart stays
more straight than the other, sharply bent (which might
result from differences in surface condition --slickness).
Whereas the carrick bend has the SParts staying more
each-to-its-own-side business & formation; capsizing from
the lattice form can be problematic in mixed cordage, but
once dressed, loading shouldn't introduce biases.
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But to the issue of practical knots, I defend this knot's
presence under that title in that it presents a possible
joint, with the brevity of the sheet bend, square knot,
& grass bend , which can be used for small tasks of little
consequence (albeit perhaps w/no more to recommend
it than *variety* --but maybe the forcible loosening ).
One could see all this captured under a theoretical remark
put under the ...Explorations... heading, too.
--dl*
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After reading the latest installments here I went to the shed and got an old worn and hard bull rope of .75 inches. I tied it using the method I have described earlier, all in hand and yanked it tight as I could fast. I did not fiddle with slow dressing as I don't seem to need to do this with this knot (even with the smallest of cords).
If I can get through my soggy yard in the days to come I will tie this in a loop fashion around a tree and using my truck I will see if it turns loose under a load that I can not approximate by hand and leg.
SS
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This bight can serve as a rope-made pin for the "grenade" :), that, if pulled, can release the corresponding tail, and untie thebend - as mentioned in Reply#53 (1). I can not predict if there will ever be a practical use for this trigger...but many quick-release mechanisms are utilized for safety/security purposes.
1. http://igkt.net/sm/index.php?topic=3716.msg21551#msg21551
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The symmetric sheet bend would be more stable with a Zeppelin-type tuck, although this makes the bend less simple. The tucks also make the SSB look more like my "small fancy bend". :)
Mike
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The tucks also make the SSB look more like my "small fancy bend". :)
Yes, because we get fig.8 shaped links, and the bend becomes an interlocked fig. 8 bend (1). One tuck more, in a one-tuck bend, is too much , I am afraid ! :) On such simple a thing, adding something, however small,, is equivalent of subtracting almost anything else...because this bend has not much more, than its outmost simplicity.
1) http://igkt.net/sm/index.php?topic=3148.0
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I have tied the symmetric Sheet bend and the What knot - GrassBend (ABoK#1406-ABoK#1490) with various elastic and springy cords. Big advantage for the WhatKnot-GrassBend ! While the elasticity of the material tends to push the tails of the symmetric Sheet bend in the wrong place, and the knot to degenerate into its evil impostor, it helps the tails of the WhatKnot-GrassBend remain in the correct place - and the knot to close into the secure form, and not degenerate into a loose Thief knot. ( The springy elastic material seems to be at least as helpfull - and perhaps even more... - for the GrassBend, as the - commonly used fot this bend - flat semiflexible material.)
So, if you have an elastic, springy material, you better tie the closest relative of the symmetric Sheet bend, the WhatKnot -GrassBend (ABoK#1406 -ABoK#1490).
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The ingenious knot tyer Desmond Mandeville had found a way to arrive at the "Symmetric Sheet bend" ( which he had also met, and had named "Tumbling Thief" bend ) by a certain re-arrangement of a Carrick mat. See the attached picture. I have copied this image from the chapter " Trambles ", written by Geoffrey Budworth, at : History and Science of Knots, World Scientific, 1996, p. 306
In the same book, p. 316, one can find many references to Desmond Mandeville s work, some of which was published in Knotting Matters.
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I think that the method "sheet bend adding a tuck'" is much easier
There are many ways a knot can be tied, and the "Symmetric Sheet bend" / "Tumbling Thief bend", although the most simple symmetric bend possible, is no exception. The series of moves shown by Desmond Mandeville is not supposed to be an "easy" tying method, of course - it is a manipulation and transformation of one particular Carrick mat ( the a ) to another ( the e ). D. Mandeville had built a whole "mini-universe" of known and unknown bends, by performing similar manipulations / transformations. To be able to explore the hidden relations between apparently different knots, and arrive at any one of them starting from any other, by a series of similar "moves", seems fascinating to me. In a sense, all the thousands of practical knots are but a limited number of them, plus a certain sequence of such "operations". That is all what science is about, an effort to "reduce" the apparent multiplicity / infinity of phenomena to a small / limited number of simple "elements" - to "make everything as simple as possible, but not simpler". :)
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Two pictures of a Tumbling Thief knot, after hard loading : I use to haul a horizontal line taut by a Trucker s hitch, then step and jump on it, and then I repeat the procedure a number of times, until the nub of a bend in the middle of it becomes rock-solid... It seems that the more the bend is tensioned, the less vulnerable to any accidental release and "insecure" it looks ( even to people that do not understand how the friction between two adjacent lines is greatly enhanced by their local saddle-shaped deformations ), while the easiness of its untying remains exactly the same.