A round turn + U turn jam resistant TIB bowline(not double)

[agent_smith]

Indeed, i had problems to classify various knot structures, but your clever concept of `virtual bowlines`, is more appropriate for nipping structures with geometry that deviates from the simple helical nipping loop, but retains the jam resistance property, serving me well enough, as it extends the scope of the bowline variable, including more structures that would fit in.

I would add that a qualifying requirement is that the nipping structure must also be ‘TIB’.
The full suite of qualifying requirements for a nipping structure being:
TIB
loaded at both ends
jam resistant (although this requirement might be problematic with complex structures such as the #1188 Constrictor hitch).

But the question still stands!! Would i have to strangle the WE to the SPart? In other words, is this knot inherently secure? You claim that it is not, but i want to know which is the crucial factor that excludes it from being so. I have tied all the inherently secure bowlines depicted in your paper, which are based on a simple nipping component, and a more complex collar structure that secures and buries the tail. But what about the opposite, when it comes to a more complex nipping structure and a simplified collar structure, like the one presented here?[i] I do not wish to add more complexity to the knot with extra tail maneuvers,[/i] but i can't help wοndering, if a direct first line of defence would enhance the safety factor, producing an inherently secure knot!!

If the bight structure is left in the standard form of #1010 (where the legs of the collar are straight and continue on to form a parallel bight structure) - retardation of tail slippage is reliant only on the nipping structure.
In my view, additional tail maneuvers are required to boost security.
Examples of such tail maneuvers are found in the EBSB Bowline, Lees Link Bowline and Scotts locked Bowline - all of which are inherently secure.

If further tail maneuvers are required to achieve security beyond the base knot form - for example, an additional strangle around the SPart, this implies the base structure is not secure.
For example, Lees link Bowline does not require further tail maneuvers to boost security - it is inherently secure in its native form.

I am of the view that a ‘Bowline’ with a parallel bight structure in the form of #1010 will (in all likelihood) not be inherently secure.

[eric22]

There is always the chance that someone might post a structure,(Alan Lee is a usual suspect), which could negate or expand all the known theory on bowlines, advancing new concepts and triggering similar discussions.

Hi All, Too much time and energy for me to read what you guys wrote, I don’t quite understand too.
But I do look at your Bowline_with_a_constrictor_ collar_structure_ loose knot.
I make a litter change on the tail, seem like it look nicer this way, see if you like this way or not ?
謝謝 alanleeknots.

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[kost_greg]

@agent_smith post:21

If further tail maneuvers are required to achieve security beyond the base knot form - for example, an additional strangle around the SPart, this implies the base structure is not secure.

if i wanted to use an additional strangle around the SPart, i would not bother exploring more complex structures, I would use instead a simple standard 1010 bowline (or 1013 double), in TIB fashion, with the WE strangled to lock down the structure.

@agent_smith post:21

Examples of such tail maneuvers are found in the EBSB Bowline, Lees Link Bowline and Scotts locked Bowline - all of which are inherently secure.

By the way, i noticed that you have not declared the Ampersand bowline inherently secure!! Are you not satisfied with its locking mechanism which compresses the working end in a neat and effective way, or have you just encountered some vulnerabilities regarding safety?

@alanleeknots post:22

Hi All, Too much time and energy for me to read what you guys wrote, I don’t quite understand too.
But I do look at your Bowline_with_a_constrictor_ collar_structure_ loose knot.
I make a litter change on the tail, seem like it look nicer this way, see if you like this way or not ?
謝謝 alanleeknots.

They say that an image is equal to thousand words, so you choose to speak through your work with fine quality images and videos of your enormous collection of knots and that’s all-important.Thank you for your variation of this knot, looks nice with that slight difference of the tail arrangement, although, i believe it does not alter the overall functionality of the knot. What worries me most, is the constrictor even as a collar structure,which is a known jammer, and i would care for your opinion about if this knot would survive from jamming at maximal loads.

I was hoping to extract a comment from Mr Gommers, because the knot has some resemblance with his EBSB, without the yosemite finish, (also the primary bowline knot, has the WE outside the eye,unlike the EBSB). If it turns out that it does jam, it seems that i have found another bowline knot which is not jam resistant. :o

[kost_greg]

Another virtual implementation of a bowline knot, is illustrated in the following images, along with the corresponding anti-bowline in the last picture, which i usually tend to visualize it, as an additional structure.

The nipping structure follows the Z/S chirality this time, as mentioned previously, from left to right accordingly, with two nested loops, where the left (Z), is placed twisted within the right (S), while the returning eye leg, forms the bight structure with the following pattern ~ down, up, down, up, through the two nested loops, from a conventional point of view, as shown in the first or second image, stabilizing the whole structure.

This time, the anti-blocking turn/mechanism,is the extension of the SP, which ensures the jam resistance of the knot, while the on going eye leg, tightens up the front collar and clamps the two legs of the bight component.

The TIB condition also stands in this nipping structure, and the TIB version of the knot is created if the WE is tucked back through the collar of the bowline, plus similar results could be achieved, using an S/Z nipping component.

Perhaps the knot does not win the beauty contest of knots, especially the TIB version, but it certainly does its job very well.

PS: The collar of the anti-bowline tightens up from the SP this time, while the U anti-blocking turn, is the extension of the on going eye leg (the opposite)

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[agent_smith]

Answering a previous post:

By the way, i noticed that you have not declared the Ampersand bowline inherently secure!! Are you not satisfied with its locking mechanism which compresses the working end in a neat and effective way, or have you just encountered some vulnerabilities regarding safety?

I do not regard the Ampersand Bowline as [i]inherently secure[/i]. It is obviously an improvement over the Simple (#1010) Bowline - but not an improvement to the point where it could be regarded as [i]inherently secure[/i]. And this is in no way intended to be disrespectful to Xarax... I would comment that he didn't specifically intend his Ampersand Bowline to be employed in life critical applications (eg as a tie-in knot for rock climbing). It is a fine creation, but it does not match the inherent security of (for example) Scott's locked Bowline or Lee's link Bowline or my EBSB Bowline.

The nipping structure follows the Z/S chirality this time, as mentioned previously, from left to right accordingly, with two nested loops, where the left (Z), is placed twisted within the right (S)

To be nit picky, your nipping structure is S/Z (not Z/S).
Also, Z is ‘right’ and S is ‘left’.

…

Otherwise, nice effort - keep up the good work

EDIT: Improved attached image quality

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[kost_greg]

Thank you agent_smith

I do not regard the Ampersand Bowline as inherently secure. It is obviously an improvement over the Simple (#1010) Bowline - but not an improvement to the point where it could be regarded as inherently secure. And this is in no way intended to be disrespectful to Xarax...

I do not think that a submission of opinion has anything to do with being disrespectful to anyone, if it is supported with valid arguments.Additionally, this very opinion always counts, especially when it comes from an experienced knot tyer and a professional user of knots employed in life critical applications (tie-in knots for rock climbing).But, to be honest,your answer surprises me a little, i guess i am missing something here, maybe a view from a climber’s perspective.

What i do know so far, from the co-creators of Ampersand Bowline, Xarax and Alan Lee, is that the knot has been load-tested extensively to near rupture forces by both of them, and it has been found to be a very secure, stable and jam resistant structure.Perhaps a comment of the original creators would enlighten the situation about the use of this particular knot in life critical applications, of course if they feel appropriate of doing so.

According to my point of view, i have tied the knot countless times and i think that the last tuck of the WE provides more than enough constriction with this squeezing effect from the nipping component with three rope diameters in it, resulting in a very stable supersafe TIB knot.

Furthermore, i have incorporated this technique in bowlines with less stable nipping structures, and found that it works fair well.In some cases , there is the possibility of extra-tucking the Ampersand, gaining further more security, although i believe it is not an essential move.I repeat this is purely my opinion.

To be nit picky, your nipping structure is S/Z (not Z/S). Also, Z is 'right' and S is 'left'.

I have attached an image with the initial structure of the previous knot.The left loop (when you face the picture), is a Z loop and the right loop, is an S loop according to your theory, so i call it a Z/S structure.This is the image i was refering to in my previous reply, from left to right (the WE is at the right side when you face the picture). If you consider it from right to left, then it is an S/Z structure. I guess it is a matter of definition.

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[agent_smith]

The S/Z was in reference to your bottom image (anti version).
The top image is Z/S. I should have been more clear.

With regard to my statement that the Ampersand Bowline is not inherently secure…I stand by that comment.
For example, I would not use the Ampersand Bowline as a tie-in knot for climbing/mountaineering applications (which are life critical).

The Ampersand Bowline gradually works loose with cyclic / pulsing loading events in some EN892 ‘half’ and ‘single’ ropes.
Your comment that the knot has been ‘load tested’ means what exactly?
The default ‘pull-it-till-it-yields’ type of test reveals nothing.
What matters most is the knots stability and security under cyclic/pulsing loading events, and slack shaking.
s stated, in some types of EN892 ropes - the Ampersand Bowline gradually works loose.
Because of this fact - it does not get over the finish line to be regarded as inherently security.

If you require further proof of this - I suggest you test it yourself with (for example) an Edelrid ‘Corbie’ 8.6mm EN892 certified climbing rope. Subject the knot to multiple vigorous cyclic / pulsing loading events - in conjunction with slack shaking and observe what happens…

[kost_greg]

Your comment that the knot has been 'load tested' means what exactly? The default 'pull-it-till-it-yields' type of test reveals nothing.

Personally, i do not possess a tensile test rig device to perform the default ‘pull it till it yields’ type of test, hoping that i shall obtain and set up one soon enough, because i think it is a very important test for an in depth analysis of a particular knot. And yes, i know/have seen, that pushing a knot to its limits, can reveal many things, such as the response of the knot to linear loading, tail slippage issues, jamming thresolds, how much deformation is induced and if the knot retains its initial shape, how easily it can be untied after rupture occurs e.t.c.

If you require further proof of this - I suggest you test it yourself with (for example) an Edelrid 'Corbie' 8.6mm EN892 certified climbing rope. Subject the knot to multiple vigorous cyclic / pulsing loading events - in conjunction with slack shaking and observe what happens...

The concept of cyclic/pulsing loading events in conjuction with slack shaking, sounds very important but a little ambiguous to me. I don’t have a dynamic rope with these specifications, but if i had, i don’t see how i could possibly replicate the failure mode of the Ampersand bowline that you have reported! However, if i ever get one of those, i shall certainly re-ask you about the specific parameters needed to run those cyclic/pulsing loading or slack shaking simulations and not only for the ampersand, but for other knots that i am interested in.

[agent_smith]

In relation to the typical mindset of pull-it-till-it-yields tests:

because i think it is a very important test for an in depth analysis of a particular knot

In my experience, the default mindset of pull-it-till-it-yields/breaks actually proves very little. But if you wish to pursue this standard line of thinking - I would suggest that you would need a specific objective in mind. Using a control - you could examine the effect of a change in geometry. For example, you could pull #1010 till it yields say 5 times. Then, repeat with #1010 Bowline but add 1 extra rope diameter inside the nipping loop (I suggest making it 'slipped' is the easiest method). Pull it 5 times till it yields. Compare results.

The concept of cyclic/pulsing loading events in conjunction with slack shaking, sounds very important but a little [b]ambiguous [/b]to me.

How so?

I get the distinct impression that there is some underlying motive here - what is it I wonder?

If you are after a precise ISO definition of how to undertake cyclic load testing of a knot - you will be disappointed.
Same goes for slack shaking and flogging…there is no precise standard that I can point you toward for absolute precision.

Where does that leave you?

It seems that you may find some difficulty in conceptualizing some homebrew style tests of knots.
In my case, I have several different EN892 and EN1891 certified ropes - which presumably gives me a slight advantage in terms of testing with human rated fall-arrest ropes.
When I have tied the Ampersand Bowline (for example) in 8.5mm and 8.6mm EN892 rope, and then subjected it to vigorous slack shaking, I have found that the knot grdually works loose.

How do i define vigorous slack shaking?
Hold the knot in your hand and rapidly shake it about - back n forth, sideways and up and down.

How do i define cyclic loading (of an eye knot)?
Hold the eye in one hand and the SPart in the other - now subject the knot to repetitive pulses of tension followed by slack, followed by tension again (and so on).
Each pulse cycle is just a sudden burst of force using hand strength. You can try 2 to 3 pulses per second by hand…

After doing this for a period of about 1 minute, I find that the Ampersand Bowline begins to loosen.

Interestingly, when i perform the same type of homebrew tests using Scott’s locked Bowline - it does not work loose.
What does this mean?

The same can be said of the EBSB Bowline - it does not work loose.

Now, again - would I use the Ampersand Bowline as a tie-in knot for rock climbing?
Answer = No.

…

I’m not sure how much more value I can add to this thread?

[kost_greg]

Thanks for the suggestions in relation to the pull it till it breaks type of test, as well as for the definitions of cyclic loading and slack shaking and for the detailed guidelines of performing these tests. I appreciate all the usefull information that i can get and i tend to absorb it, since i am a newbie to all these. For some time time now, i thought that there was some sort of device generating such cyclic loading oscillations, and it’s good to know that such tests can be performed only by hands.

How so?

I get the distinct impression that there is some underlying motive here - what is it I wonder?

I consider this comment unrelated to knotting!Since when does a query about a test procedure, which i totally ignore, conceal underlying motivation? If you don’t approve the word ‘ambiguous’ replace it with the word ‘unknown’. What is obvious to you, may not be for some others!Seek somewhere else for underlying motives, not in my replies, if you feel like doing so.

Now, again - would I use the Ampersand Bowline as a tie-in knot for rock climbing? Answer = No.

Yes!I think we have finally got this after three iterations of this statement (or similar) needed in all of your very last three replies!You made your point crystal clear from the very beginning, since i raised my initial question and i do respect your opinion based on your subsequent well-documented replies.Have you sensed some weakness of understanding here and you keep looping this?That’s somehow noticeable and worthy of query!

I'm not sure how much more value I can add to this thread?

Very or none!It depends on the nature of your comments!

[agent_smith]

I consider this comment unrelated to knotting!Since when does a query about a test procedure, which i totally ignore, conceal underlying motivation? If you don't approve the word 'ambiguous' replace it with the word 'unknown'. What is obvious to you, may not be for some others!Seek somewhere else for underlying motives, not in my replies, if you feel like doing so.

And how is this comment related to knotting science? You are extrapolating a meaning which is completely far removed from my curiosity. If you don't approve of the phrase [i]underlying motive[/i] , you may replace it with "thought process".

Yes!I think [b]we [/b]have finally got this after three iterations of this statement (or similar) needed in all of your very last three replies![b]You made your point crystal clear[/b] from the [b]very beginning[/b]

I'm pleased that you can see my viewpoint - however, is it necessary to overtly re-emphasize it? Your line of questioning is probing from several different angles about the security of the Ampersand Bowline - and each time you do this, I simply reply in kind with my viewpoint.

It depends on the [b]nature [/b]of your comments!

With that remark, I will assume that the [i]nature [/i]of your comments are made in good faith. I wish you all the best in your examination of the Ampersand Bowline and other explorations.

[kost_greg]

Last but not least, a helical nipping structure with a U anti-blocking turn, stabilized as a bowline knot, is shown in the following images.The first line of defence has been strengthened, since it is connected directly with the SP, while the front collar (near the eye), which clamps the legs of the bight structure, although it forms a sharp inverse turn, i believe it would survive from maximal loads, due to the other U turn of the nipping structure just before the on-going eye leg.
The result is a stable, secure, jam resistant, virtual bowline, whose TIB version is illustated in the last image.

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[kost_greg]

From the previous nipping structure, if we pass the WE down through the first loop, then we get the Tresse bowline, presented by Alpineer in the following thread, https://igkt.net/sm/index.php?topic=4321.msg26983#msg26983, another interesting, strong, stabilizing mechanism, whose gripping power might be compared with similar function structures such as the constrictor, but being more prone to jamming at maximal loads.

The nipping structure of another bowline knot, that worths to be mentioned, is shown in the first image, along with the WE passing through it.It can be derived from the previous one, if we follow another path for the SP to avoid the sharp turn of the first one. But does this mat structure look familiar? I did not know its name, but i have located it in the following link, as a Dines arthroscopic knot, analyzed by Xarax as capsized adjustable hitches. https://igkt.net/sm/index.php?topic=4107.msg24631#msg24631.
Capturing the SE with the returning eye leg, can lead to the following attached images of the corresponding bowline, in front, back or TIB fashion accordingly, if the tag end is tucked back through the collar.

In my view, this structure can not jam for two main reasons. Firstly, because of the existence of the U turn component which grips the front collar from one side and holds it, while the helical mechanism of the SP, pushes this very collar down preventing it from closing around itself.

But, this function of this helical SP component, creates a sizeable slack in the collar, which is located to the point where the on-going eye leg exits from the nipping structure and that is a drawback, at least from an aesthetics point of view. Therefore, the knot should be pre-cinched very well, (especially the collar), in the first place.

The Dines knot, illustrated in first image, can be considered as an adjustable mechanism which can capsize to this knot presented also here, https://igkt.net/sm/index.php?topic=6373.0, or a Samisen bowline without the tucking of the tag end.Additionally, it can capsize to the Chinese/loop, a well secured, more of a decorative (or practical) loopknot, which has also been tied by Alan Lee, presented in the following link as cross loopknot. https://www.youtube.com/watch?v=xM-oqzQ4cvs&t

Furthermore, a form of this knot as a bowline is presented here, which features some interesting knotting aspects.

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[kost_greg]

An eskimo Dines variation of the previous bowline is shown in first image, which somehow works out the slack problem, in that the helical mechanism, is now a function of the on going eye leg, hence the pressure to the collar is being reduced.

If we induce some light transformation to the Dines knot, we end up with the following bowline structure, illustrated in images 2,3,4 in a loose front and back view. This new nipping structure of same topology but different geometry configuration, completely eliminates the slack collar problem, retaining the jam resistance property and the Tibness of the knot. The TIB version is obtained, if the WE is tucked back through the bight component (no room for illustration).

Could these TIB nipping structures be used as two wrap hitches? The answer is positive and it can be confirmed in the following link https://igkt.net/sm/index.php?topic=4739.msg30591#msg30591.
A great series of two wrap tight hitches is presented in this thread by Squarebanksalaska, while focusing on second hitch 3, we can make out the exact same nipping structure with the bowline presented here.

The Dines knot, as a two wrap hitch, is the reverse of the hitch 3 of Squarebanksalaska.

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[kost_greg]

The Dines knot, as a starting base knot, appears to be a very interesting and productive structure. Two bowlines and two capsized knots have been derived from it, as well as it can be used as the starting point of the EHL2 tying, another end termination loopknot analyzed in this thread (reply#3, second photo)
https://igkt.net/sm/index.php?topic=6382.msg42996#msg42996.

There is one more knot illustrated in the attached images, in a loose, front and back view, that can be tied straight from the Dines with en extra tuck, shown in detail in first image. It is a symmetrical Zeppelin-like structure with no overhands in its core nub. Some might recognise this mat pattern as the Bad Brother’s bend or Valentine’s tightknot, by Luca or Valentine, (i am not sure who the original creator was), with the difference that it is transformed here into a loopknot.(reply#50, third and fourth image, link provided) https://igkt.net/sm/index.php?topic=4090.msg31980#msg31980.

[kost_greg]

The relation between the first and second structure, is that they are topologically equivalent and one can be transformed to the other. For example, the first knot, shown in first image, is a 206 crossing knot based loop, or a Samisen bowline presented in this thread, (Xarax illustrates the TIB version in his image),
https://igkt.net/sm/index.php?topic=6316.msg42451#msg42451.
Now, if we flip the collar, which clamps the working end, towards the Standing part and transform the bight structure of the returning eye leg into a straight line, we end up with the form shown in the second image.

Is this new knot structure related anyhow with the previous stuff? I believe it is the Dines knot with a clockwise twist of its helical component and a helical pretzel-like, jam resistant bowline knot is derived from this configuration, shown in the next two images, if we capture the SP with the WE.

This new nipping structure, which is TIB and loaded at both ends, as a two wrap hitch, is the reverse of the hitch 2 of Squarebanksalaska https://igkt.net/sm/index.php?topic=4739.msg30592#msg30592.

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[kost_greg]

                                           [u]TIB and Eskimo versions of the previous bowline[/u]

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