Two by Four knot (or what knot is this)

[X1]

Have you tried tying a Fisherman's Knot or Strangle Bend in monofilament fishing line? Neither are knots I would use in this material which has its own set of knots with generally a lot more wraps.

   I suppose that the first question is a rhetorical one...
   Of course, no fisherman, be him a knot tyer or not,  , would ever use those knots in his monofilament fishing lines !
   However, that was not what I replied to your statement, that :

the Strangle bend in monofilament... is not a knot which appeals for this material because of the difficulty of tying.

   I replied to this "difficulty of tying" . 
   The Strangle bend is very easy to tie, perhaps even easier than the double fisherman s knot (=bend). It was meant to be a bend for ropes, not a fishing knot ! I do not know if it will hold better if tied on monofilament, than a double fisherman s knot(=bend), tied on the same monofilament. And I do not know if it will hold better or worse than the double fisherman s knot (=bend), if both knots are tied on another kind of slippery material, Spectra/Dyneema for example.
   However, my question was not this... I wonder if the fact that a knot holds better or worse than another, " similar"  knot when both are tied on a very slippery material, can be extrapolated in the case where the same knots will both be tied on another, less slippery material.
   Why am I asking this ? Because, if it turns out that we could answer this question in the affirmative, we can test out knots in monofilament, see which knots hold better than the others, and then suppose that the same knots will also hold better than the others when they will be tied on the common materials we use in everyday life. So, we could possibly measure the degree of slippage of knots when they are tied on monofilament, and use the results as a means of predicting a similar behaviour when the same knots will be tied on less slippery materials.

[James Petersen]

Thank you to all who have responded to the original post about the knot tied with two round turns around two round turns. Your replies have all been very informative and interesting, and it is easy to get carried away in discussions about other more or less related knots.

I agree with many of the replies that there are probably better loops and bends for most purposes. I especially like the strangle knot on strangle knot posted by X1. I further agree that the 2x4 knot has some similarities to a variation of the anchor bend (ABOK 1843, if I am not mistaken), I don't really see it as being a variation of that knot -- each part only encircles two diameters of the opposing part.

However, I am still left with the original question, to wit, whether anyone has actually seen this knot described or in use. I had thought that this knot was too simple to have been overlooked, but it seems that may not have been the case.

Thanks again to all who have responded for your warmth and erudition.

[X1]

   I had thought that this knot was too simple to have been overlooked

   You are not alone ! Ashley thought the same thing...
 "I supposed that everything of so simple a nature had already being discovered." ( ABoK. p. 7 )
 
  Who knows how many more "too simple knots" are still hiding under our noses...

[kd8eeh]

I do not quite use this knot, but i use an extremely similar knot, to make rope nets.  The only difference between what i use and what you use is that when i tie it, i have the two loops going the opposite direction to pass through each other, while you use the loops going in the same direction (what i mean by this is that i use two loops like the two loops you would use to tie a cow hitch, while you use two loops like those you would use to tie a clove hitch.).  I also tie it by thing the last carrick bend in abok (i forget the number- it's in the bends chapter and described as the worst possible carrick bend)  and then doubling the loops from there.  When i say net, what i mean is that it is the knot i use to tie together a bunch of ropes in a pattern of squares; at every point where two ropes intersect, i tie one.  There are a lot of knots that do this nicely, but this is my favorite one.  Also, I had never seen anyone else tie it before.

Just a note on this forum: when there are as many knots as there are, it is very hard to remember all of them and use all of them.  Everyone has their own preferences when it comes time to actually tie something, and most other knots are more for fun.  That said, people still do tie all sorts of knots, and those are the people here.  So, when you ask a question like that, it's very, very hard to conclusively determine if anyone else has tied the knot before and described it.  New knots are invented every day, so the fact anyone can even know anything about all the knots our members know of is impressive.  However, those questions are notoriously hard to answer.  I find it better to think about the real question "what would i use this knot for?" and then tell everyone else about it.  Chances are, the knot will have tons of other uses, and tons of similar, equally interesting knots, and those are some of the funnest things to find. 

Also, even if the knot has been tied before, chances are it was not formaly described at any length.  In addition, nothing is ever too simple to be overlooked.  Almost all knots of any theoretical or practical interest are simple, and we have described only a fraction of all of those.

As an example, I have tied almost the same knot that you show here, in almost every detail, hundreds of times, yet i have never before tied this knot.  On some level, the fact that something so simple is so often overlooked is one of the greatest things about knots.

[roo]

On some level, the fact that something so simple is so often overlooked is one of the greatest things about knots.

More often the reasons knots are not documented is not because they were overlooked, but rather because they were looked at and rejected for one or more reasons.

That's not necessarily a bad thing.  If all knots are equally covered, you'd soon be so buried in countless tangles, you'd have a much harder time finding good knots.

[Dan_Lehman]

On some level, the fact that something so simple is so often overlooked is one of the greatest things about knots.

More often the reasons knots are not documented is not because they were overlooked,
but rather because they were looked at and rejected for one or more reasons.

How do you support this assertion?
(How does one go about researching this proposition?)

And what do you count as "(not-over-)looked" ?!  --e.g., is it
a matter of publication, or rather some awareness (of we who
are counting) of existence.

We can see, IMO, cases of things in common usage but not in
books (e.g., what I call the "reverse ground-line hitch" binding
hitch of commercial fishing, to bind lines & netting, to attach
netting; yes, the geometry is published, but not this common
application, to my awareness),
and some things well-published in books that aren't found
"in the wild" (e.g., the sheepshank is something foreign to my
observation, and also the interlocked-overhands knots).

.:.  I surmise that the greatest number in our counting will be
of structures simply not considered --we have the infinity of
things on our side, here, or some large number, however one
works "simple" into the counting as a constraint on number.

One should wonder about what sort of process(es) knots endure
in coming to be known, to be part of the state of the practice.


--dl*
====

[roo]

On some level, the fact that something so simple is so often overlooked is one of the greatest things about knots.

More often the reasons knots are not documented is not because they were overlooked,
but rather because they were looked at and rejected for one or more reasons.

How do you support this assertion?

There's not many of us, but knot enthusiasts evaluate thousands of knots and pass on, in my experience 99%+ of them for real practical use.  I've evaluated and rejected the knot in this thread over a decade ago, as an aside.

These thousands of discarded knots far exceeds the number of new knots that are being put to use.  I can't imagine this even being a close call.

[SS369]

There's not many of us, but knot enthusiasts evaluate thousands of knots and pass on, in my experience 99%+ of them for real practical use.  I've evaluated and rejected the knot in this thread over a decade ago, as an aside.

These thousands of discarded knots far exceeds the number of new knots that are being put to use.  I can't imagine this even being a close call.

I feel James posted his offering in the correct place. It was new to him and he could not find reference to it in his searching and I believe he wanted to discuss it.

I also constructed this form of knot, but as a loop and found it to have some merits, although it does jam easily in the cordage I tied it with. But, that is not necessarily always a bad thing, imo.

We sometimes look at various "new (to others)" knots, not because they fail with ropes of yesteryear, but because they may lead to a knot or knots that can work with the upcoming difficult ropes.

This Board is for exploration and if and when an offering is confirmed sufficiently by some consensus it can be entered into the practical hall of fame.

SS

[roo]

There's not many of us, but knot enthusiasts evaluate thousands of knots and pass on, in my experience 99%+ of them for real practical use.  I've evaluated and rejected the knot in this thread over a decade ago, as an aside.

These thousands of discarded knots far exceeds the number of new knots that are being put to use.  I can't imagine this even being a close call.

I feel James posted his offering in the correct place. It was new to him and he could not find reference to it in his searching and I believe he wanted to discuss it.

I also constructed this form of knot, but as a loop and found it to have some merits, although it does jam easily in the cordage I tied it with. But, that is not necessarily always a bad thing, imo.

We sometimes look at various "new (to others)" knots, not because they fail with ropes of yesteryear, but because they may lead to a knot or knots that can work with the upcoming difficult ropes.

This Board is for exploration and if and when an offering is confirmed sufficiently by some consensus it can be entered into the practical hall of fame.

SS

I was replying to a comment by Dan.  I was not intending to weigh in on any of the issues you're discussing here.

[Dan_Lehman]

On some level, the fact that something so simple is so often overlooked is one of the greatest things about knots.

More often the reasons knots are not documented is not because they were overlooked,
but rather because they were looked at and rejected for one or more reasons.

How do you support this assertion?

[A.] There's not many of us, but knot enthusiasts
[B.] evaluate thousands of knots and
[C.] pass on, in my experience 99%+ of them for real practical use.
[D.] I've evaluated and rejected the knot in this thread over a decade ago, as an aside.

True, we are a small group; but do folks such as us
even matter --what WE do/don't, so what?
Ashley has published some of his whims, but to what effect
that, even?  --that he published what Day christened "Ashley's Bend"
and which publication has been now echoed elsewhere,
does it make a dent in the Wild?

Re B, that's a powerful figure, which I doubt.  I'd count now
some 2000 --just a rough guesstimate, with some actual
counting of *segments* of the work-- knots for myself
that are (self-)recorded and figure maybe another 25-50%
(ha : I've a low standard!) not so?  I really wonder that many
others can do as much, and then of what the overlap is.

Re C, "pass on" first manifest in me as "give to", but you
mean "ignore", "pass by"!

Re D, yes, this sort of knot one would expect to have seen
some hands & consideration play.  Can't say that I did so.
 

[kd8eeh]

I would like to be able to make a difference in the wild, even if it seems impossible.  The Guild does not exactly advertise; i went years before i found out about this group, and i am sure there are several knot tiers who know nothing about anyone else like them.  Also, to learn knots of their own means, these people may provide invaluble new viewpoints on knots.  I would say our best chance to educate more people would be to go to schools, and teach knots.  Besides which, an education is hardly complete if someone lacks such crucial skills as how to tie a bowline.  Personally, i think that organizing something like this http://igkt.net/sm/index.php?topic=4141.0 is our best option.  In this way, we could appeal to vast audiences of students, and perhaps even impact "the wild".  At the very least, we could get the guild's name out there a little more, and appeal to those who are already interested.

[James Petersen]

After looking more carefully at ABOK, I realize that I gave the incorrect number (ABOK 1406) for the knot that led me to discover the knot that is the topic of this thread. The correct number should have been ABOK 1407, which Ashley characterizes as "at all times unpredictable." Having doubled each of the round turns, I arrived at the current knot, which is to the extent that I have experimented with it, at all times predictable, easy to remember, and secure -- bordering on impossible to untie if heavily loaded, especially in frictive material and shock cord.

It occured to me that if I were to take this single-round-turn bend/loop (one arrangement of the whatknot (ABOK 1407), and pass the working end under the standing end on each cord, I would end with four additional variations, two of which turn out to be two strand Matthew Walker knots -- an overhand knot on an overhand knot. So one could argue that ABOK 1407 and the two strand Matthew Walker are members of a group of knots having a round turn with or without a tuck on each turn.

Having doubled each of the round turns in ABOK 1407, I arrived at the knot which is the subject of the current thread.  X1 was so kind as to post pictures of similar ans related knots (the strangle bend, the trefoil bend, and the clove hitch bend -- have any of these been officilally described? If they haven't, they deserve to be). I would propose that these knots bear the same resemblance to the 2x4 (two-round-turns) bend/loop as the Matthew Walker bears to the whatknot (ABOK 1407) -- the most basic form of the knots in each group start with round turns and progress to more complex forms when the working end rides over or is passed under a previous turn or turns in the same cord.

round turn > overhand knot

round turn on round turn (ABOK 1407) > Matthew Walker knot


two round turns > clove hitch
                > strangle knot
                > constrictor knot
                > picket line hitch
                > etc.

two round turns on two round turns      >   strangle bend
                                        >   clove hitch bend
                                        >   etc.


Also, if only one of the round turns is doubled, we arrive at an knot that seems equally as predictable, very stable, and perhaps nearly as strong as the two-round-turns bend/loop, although I prefer the loop variant in the photo.
                                               

[James Petersen]

After more fiddling with tying the two-round-turns loop, I realized that there are actually eight possible configurations, with four being mirror images of the other four. Those where the working end passes over the round turns before passing through the center tend to sit more squarely when loaded, while those where the working end passes through the center beginning on the same side of the knot sit more diagonally.

Up to this point, I don't know which kind of loop is stronger. But this weekend, I got myself set up to start testing the strength of the knots. I plan to test them in various types of string and small cordage, including small diameter shock cord.

I began doing some strength testing on one of the strings I had planned to use to test some knots, and to my dismay, having carried out the same test 30 times, found that it broke anywhere between 3.7 - 8.0 kg, averaging 5.87 kg.  The length of the string under testing was approximately 40cm. With that much variation in the breaking strain of the string, how many tests should I conduct on the string without knots until I have what would be an acceptable average breaking strength? Or would it be better to test a longer length of string each time? And how many times would I have to test each knot? Or would it be better to simply try to find a more consistent string? Any thoughts or guidance would be greatly appreciated.

[X1]

   

would it be better to simply try to find a more consistent string?

   My gut feeling tells me that if you should use a thicker cord, of a larger diameter - say, of 1/4 of an inch, at least. In such a cord, a minor local default would not be able to play a major global role, and your results will be more consistent. You can plot them, and exclude the one or two that may happen to lie way outside an expected smooth, dense bell curve. 20 results per knot per material would be more than enough I guess - provided you will be careful to dress the specimens with the same way, and load them with the same (very slow) pace.
   If you use a solid braid rope, you will not have to test the mirror symmetric knots, and your segments will remain round. Easily flattened ropes can lead to very different results - because most probably they will not be flattened at the same points, to the same degree. The more individual characteristics and "memories" a material can have, the more different the results that it is likely to generate. To address this issue, I have thought of using nylon ropes. Nylon can be stretched a lot, so it would probably produce more consistent results - because the distribution of tensile forces inside the knot s nub would be more balanced, and any local maxima would be spread and smoothed out, on a larger area.
   I believe that comparative tests are always more useful. It would be great if you could test your knots against the golden standards of bends - the Zeppelin bend, the Water bend and the double 8 bend.
   At last, a knot tyer that does not only TALK about his knots, but TESTS them ! A miracle !  Good luck !

[James Petersen]

   I have completed a small test of the two-round-turns bend/loop (I originally called it the 2x4 -- not sure what I was thinking, because 2x2 would have been more logical). I used 3 strand fairly loosely Z-laid nylon twine, each strand having 10 filaments. Over the course of the tests, the twine had an average breaking strength of 34.98 kg. I tested only the bend form of the knot and in only one configuration -- that with both round turns following the lay of the twine.  As X1 suggested, I tested other knots as well, including the zeppelin bend, the water/tape knot, and the figure 8 bend.

   Testing was carried out by first loading the twine until it failed. Next, the four knots were tested -- the zeppelin bend, the two-round-turns bend, water knot or tape bend, and the figure 8 bend. I followed this  procedure throughout the testing to (hopefully)  mitigate any gradual variance in the breaking strength of the twine.

   The two round turns bend can be made in several ways in relation to the lay of the rope or twine. I tested it with the round turns made in the direction of the lay. That is to say I tightened the lay of the first twine until a round turn formed then doubled it in that direction. The second line was laid parallel and the round turns were made around the first line in the same direction. I had originally planned to test knots tied with the other two orientations -- one set of round turns with the lay and one against the lay, and both sets or round turns against the lay --  but I found that they ran in all instances and stopped testing them with the current twine.

   I first discovered this knot while fiddling with ways of tying the bowline and was/am most interested in it as a loop knot, but I thought I would start out by testing it as a bend. I plan to do further testing as a bend in braided line before starting testing as a loop in both twisted and braided line. Since a variation of the knot can also be tied with one round turn on two round turns, I feel it is probably better to refer to them as 2x2-round-turns bends/loops and 1x2-round-turns bends/loops.

   All of this having been said, the results were as follows:

Average load at failure:

twine........................34.98 kg
zeppelin bend ................27.15 kg  or ........77.63 %
2x2-round-turns bend ........70.95 kg  or ........70.95 %
figure 8 bend................31.10 kg  or ........88.91 % -- amazing!
water/tape bend..............24.25 kg  or ........69.33 % **

** The water bend slipped badly in 6 out of 20 tests, two of which later jammed and failed at the knot, which were included in the data. The other four instances were left out of the data for the average failure load for the knot. The average is based on the other 16 tests.

   Overall, I was impressed with the performance of the 2x2-round-turns bend as tested, in the medium it was tested. I hope to do further tests in other media, specifically, in tighter-laid synthetic and natural cordage and in natural and synthetic braided cordage.