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…
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
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.
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.
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*
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
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
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
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
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 ?
Thank you Derek. It is always a pleasure for me to discuss with you about simple, fundamental knotting mechanisms.
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.. :).
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.
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.
I would like to ask a question, related with matters discussed in this thread.
We have two knots :
- 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.
- 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… :))
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
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.
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
I thought the same thing of this insecure “bend” for much the same reasons until SS369 started calling it secure.
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
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.
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 …
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.
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 ?