Ring loading is ill-defined (vague)

[SS369]

I think that the term ?Ring Loading? is a very specialized term that only a few rope users grasp the meaning of. Yes, some users of cord may have enjoyed the tag over the years in a small circle of common users.
That said, I believe that there is a opportunity to discuss a more in depth explanation to understand and clarify loading profiles of a eye loop.

In agent-smith?s defense; he brings a lot of work to his discussions/contributions and asks only for considered responses/contributions. And I believe his experience and professional rope employment.

To bring counterpoints is welcome, but without the denigrating remarks (is expected).

So, back on topic, for example; if you have a loop (not ring) that has three different loads applied to it, in different directions, is this ring loading? Will the loaded loop resemble a ring?

Loop loading seems to be more clear and I believe that the common person would be inclined to understand this term more readily.

In my opinion, more specificity is welcomed for this discussion.

SS

[agent_smith]

Thanks to the moderator (again) for calling out bad behavior.

Given the purpose of this section of the IGKT forum (which is to discuss knotting concepts and explorations) - it is puzzling why some individuals choose to engage in belligerent behavior.
I do have faith in the human race - but, the underlying motivations of these individuals calls my faith into question.

Anyhow, I have attached yet another diagram illustrating 3 different loading profiles on the eye of a fixed eye knot.
The timing of this is interesting because I had been in various discussions about appropriate terminology to describe these loading profiles.
My original thoughts centered on 'cross-loading' - and thus 'radial cross-loading' and longitudinal cross-loading' grew from that concept.
Recently, I went back to the drawing board and thought that axial and transverse could also be appropriate.

In any case, the complexities of the English language and engineering terms which guide my thoughts.

The attached image clearly shows the different directions a fixed eye can be loaded.
Obviously, all 3 cant be 'ring loading' - because each is loaded in a different way.
Furthermore, what is the precise definition of 'ring loading' - and if there is a precise definition, how does that definition apply to each of the loading directions I have shown?

Informed and considered replies are always welcome - but bad behavior and offensive replies will be called out.

[Dan_Lehman]

Anyhow, I have attached yet another diagram
illustrating 3 different loading profiles on the eye of a fixed eye knot.
//
The attached image clearly shows the different directions a fixed eye can be loaded.
Obviously, all 3 cant be 'ring loading' - because each is loaded in a different way.

No, you have a specious image, and,
"specious reasoning, however fair,
is like missing a link in a chain of thought
and praxis seeks to pull the chain taut
it becomes apparent what isn't there!"

I.p., your image with 4 biners connected
to an eye is speciously set to render that
eye *round*: LOAD the biners and you will
see ring-loading on the KNOT as the eye
legs running to the knot are pulled in opposition
to each other (as you show in another image),
and matters little about there being additional
points of contact with the eye --the relation of
load to knot is the critical point.
As I said many posts back:
Others know exactly what is
meant, which you show as "l.cross-loading" --i.e.,
loading the eye qua ring such that the knot is
loaded qua end-2-end joint.

--dl*
====

[agent_smith]

In reply to Dan:
Thanks for your comment in relation to my imagined specious reasoning.

There isn't anything of a specious nature here - its simply discussion and I am simply presenting information to show various loading profiles.

I respectfully disagree with your analysis of the circumferential loading profile in comparison to the transverse loading profile.
Note that these are just working titles - as I had previously advanced terms such as 'cross-loading' (with radial and longitudinal directions).

With regard to my image of circumferential loading - I simply set the photo showing only 4 loading directions on the fixed eye.
I could just as easily showed 8 or more loading directions - which does indeed expand the eye outwards.
Consider that one of the multiple loading directions could also be 'downwards' in the axial / longitudinal direction.

These multiple loading points are different to the photo which shows only a transverse / radial loading direction.
The 'transverse' loading profile isolates all load from the SParts.

However, with multiple loading directions within the fixed eye (to induce circumferential loading) - partial loading occurs on the SParts (ie the SParts are not isolated).

Do I really need to take a photo with 8 or more loading directions within the fixed eye to demonstrate this?
Circumferential loading on a fixed eye emulates a rigging plate - which enable multiple connections and multiple loading directions.

[Dan_Lehman]

In reply to Dan:
Thanks for your comment in relation to my imagined specious reasoning.

There isn't anything of a specious nature here

What I point to as specious is the image of the eye
with all the loadings WHEN THE POINT of the term
"ring-loading" --the point from those coining it--
relates simply to the loading of the eye legs in
opposition to each other, hence, qua ends-joint
--which is a straight line through the knot,
irrespective of what occurs farther out : the knot
feels the leg-vs-leg spread of loading.  A paradigm
situation might be belaying from one's tie-in eye
vs. belay loop.  (A rumored case was an injured
climber being helicopter-hoisted by a connection
into his tie-in bowline --not good.)

To this, if one really wishes to complicate things,
one might try including 3-way loading --i.e., keeping
some SPart loading along with eye loading;
and this then is going to change angles,
likely to be seen as going from some rather
extreme, "a different animal" state to what
might be more accepted as within-possible-range
of eye spread (say, angle range 40..90deg?)

Just as one might prefer to separate degree
of jamming at within-safe-working-load forces
from that coming only at higher, nigh rupture
forces.


 - - - - - - - - - -

A separate but worthy area of investigation is the
handling of varied-direction/-state forces upon
mid-line eye knots :: it's all well and good that
some testing is done on some state of the
butterfly, e.g., loaded eye-vs-a-SPart
(pick one ; but know that it's an asymmetric knot
and the one is a bit different from the other!),
AND THEN loaded *through*, end-2-end.
The first loading can be seen as a particular
(maybe not so good...) setting of the knot
for its next loading.
Going from A-loading to B-loading might work,
but not so much so going from B-loading back to A's.

(To this thinking should come some notes about
when such variance is expected, or at least possible;
there might be cases where loading falls only within
some limited variance where problems won't arise.)

--dl*
====

[agent_smith]

In reply to Dan:

WHEN THE POINT of the term
"ring-loading" --the point from those coining it--
relates simply to the loading of the eye legs in
opposition to each other, hence, qua ends-joint
--which is a straight line through the knot,

The POINT of my starting this thread topic was simply to elicit informed discussion about the vagaries of the term 'ring' loading - particularly within the broader context of the different loading directions on a fixed eye. The term ring implies a circle or something that is round.

I mean, what is the ordinary dictionary meaning of the word 'ring'?

Now - there is nothing offensive or belligerent in wanting to elicit discussion about the term 'ring' loading. I noted that there was no body of research or other technical papers exploring the concept of 'ring' loading. It s highly likely that this is the only topic thread on the internet where the term 'ring' loading is being discussed.

Dan - you may find comfort in visualizing a transverse/radial loading direction on a fixed eye - that forces the 2 eye legs into 180 degrees opposition. And thats fine, you are perfectly entitled to your own opinions and conceptualizations.

I however, am of the view that the term 'ring' loading is not the best descriptor for your conceptualized loading direction (which is a transverse direction).
As stated, what is a 'ring' and what is its commonly understood shape?

In my view, the term 'ring' loading is more akin to circumferential loading (hoop stress) where the eye of a fixed eye knot is expanded outwardly in all directions.
There is nothing offensive with holding a view that 'ring' loading is not the best use of the English language.

At present, I am leaning more towards the term 'transverse' loading (superseding my earlier term 'cross-loading' in the radial direction).
Transverse loading isolates all load from the SPart.
There is also axial loading (which is aligned longitudinally with respect to the SPart). Axial loading induces force on the SPart.
Transverse loading of a fixed eye isolates load from the SPart.

And then there is circumferential loading - which expands the fixed eye. Circumferential loading does not fully isolate load from the SPart).

Dan, you may dislike these terms - and that's your prerogative.
Knotting terminology has its roots from ancient sailing times and has evolved through several important books eg Ashley Book of Knots (ABoK), The Art of Knotting and Splicing, etc.
It is now 2020 and I think it is time to revisit some of these long held beliefs and concepts of terminology.

The term ring loading is absent from ABoK, and other noteworthy books. Then again, many of our more modern knotting concepts are missing from these previous publications (because the world has advanced somewhat). I think the term 'ring' loading likely has its roots in this IGKT forum - and propagated (somewhat).

EDIT NOTE:
An image of circumferential loading is attached.

[DerekSmith]

Hi Mark,

Thank you for starting this thread.  It has merit, both in reaffirming what the majority of contributors understand by this term, plus it gives us the opportunity to dispel muddled and/or erroneous concepts.

So, my opinion on the term 'Ring Loading', pertaining to fixed loop knots, and one which I have found no reason to modify, is as follows:-

1. Ring loading is a simple and well understood term which has a single variable aspect.
2. There are not 'classes' of Ring Loading, but there are degrees of Ring Loading.
3.  Fixed Loop knots are cordage Force Machines which transpose and translate forces between the loop legs and the primary load bearing SP.
4.  Ring Loading is defined by the angle subtended by the two loop legs.
5. When the loop legs are parallel, the subtended angle is zero and there is no, ie. 0% Ring Loading.
6.  When the loop legs are diametrically opposite, the subtended angle is 180 degrees and the knot is experiencing 100%, i.e. fully  Ring Loaded.
7. When the loop legs subtend and angle of 120 degrees, both loop legs and the SP are potentially subjected to equal tension loads.
8. At subtended angles above 120 degrees, the forces required in the loop legs needed to balance the SP load, rise exponentially to multiples of the applied SP load.
9. All knots respond to applied forces, some are capable of resisting change, while some are liable to capsize.  By way of example, THE Bowline is reasonably stable to low levels of Ring Loading ( ca 20 degrees and less), but is at high risk of failure at high levels, while other knots such as the Carrick Loop retain their stable structure.
10. All loop knots can experience Ring Loading (an angle subtended by the loop legs).  To factor this into our knot usage, we need to be cognisant of the impact of divergent force vectors and be familiar with the response our knot structures have to applied loads.

As a footnote - it does not matter how a force has become originated in a cord, it only matters to the knot what the force and its vector are - AS THEY ENTER THE KNOT.

I hope that you can now agree that Ring Loading is neither 'Ill defined' nor 'vague', and that the concensus of opinions are in agreement and at odds with your posted contentions.

[Keystoner]

Good Lord. 

[agent_smith]

in reply to Derek Smith:

Ring loading is a simple and well understood term which has a single variable aspect.

I personally disagree. And there is no ill will, no angst and no belligerence in the concept of disagreement.
Its simply that I hold a different view to you (and I am entitled to hold different views).

There are not 'classes' of Ring Loading, but there are degrees of Ring Loading.

I respectfully disagree - and the purpose of starting this discussion topic was to elicit informed discussion.

When the loop legs are parallel, the subtended angle is zero and there is no, ie. 0% Ring Loading

And here I prefer the term 'eye legs' - because only a loop can have a particular chirality (left-handed or right-handed) - the fixed eye of a knot does not have chirality (eg the eye of #1047 F8 has no chirality). Again - this is my theoretical view...
In any case, this type of loading profile has never actually been described in technical detail by knot book authors.
I had advanced the term 'axial loading' (and earlier - longitudinal loading).
In advancing such a term - it is simply discussion - it is not belligerent or offensive. The whole point of this section of the IGKT forum is to engage in technical discussions about theoretical knotting concepts (without fear or favor).

When the loop legs are diametrically opposite, the subtended angle is 180 degrees and the knot is experiencing 100%, i.e. fully  Ring Loaded.

And here I would respectfully disagree in the application of therm 'ring' (which - in the ordinary dictionary meaning means a circle - or round).
I prefer to conceptualize this type of loading as transverse loading (and my earlier term was cross-loading in the radial direction).

All loop knots can experience Ring Loading (an angle subtended by the loop legs).

I would re-word this is follows:
The eye of a fixed eye knot can be loaded in a number of different directions as follows:
[ ] axial loading
[ ] transverse loading
[ ] circumferential loading
Again - in conceptualizing the loading profiles in this way - it is not an example of a mental deficit or a lack of professionalism or any form of belligerence. It is simply a discussion and an expression of views in accordance with the spirit of this section of the IGKT forum.

I hope that you can now agree that Ring Loading is neither 'Ill defined' nor 'vague', and that the concensus of opinions are in agreement and at odds with your posted contentions.

I would like to express to you that I disagree - and that it is okay for me to disagree.
There is also an underlying tone in your narrative which does not accord with the spirit of this section of the IGKT forum.
For example, using sentence structure such as 'consensus of opinion' and... 'at odds with your posted contentions' - is using what I call 'social proof' to back your contention'.
The reference to 'consensus of opinions' isn't necessary.
You could simply state - my personal view is.... (enter your view).

And nothing is at 'odds' - its just discussion.
Keep in mind what the purpose of the IGKT is.

I will have more working photos of various loading profiles on the eye of a fixed eye knot at some stage....

[DerekSmith]

in reply to Derek Smith:

Ring loading is a simple and well understood term which has a single variable aspect.

I personally disagree. And there is no ill will, no angst and no belligerence in the concept of disagreement.
Its simply that I hold a different view to you (and I am entitled to hold different views).

There are not 'classes' of Ring Loading, but there are degrees of Ring Loading.

I respectfully disagree - and the purpose of starting this discussion topic was to elicit informed discussion.

Mark, I totally applaud your right to hold a view different from mine (and from the majority of other posters) - indeed, sometimes the lone voice can even be right...

Equally, I fully support your desire to elicit informed discussion, as indeed do I.

When the loop legs are parallel, the subtended angle is zero and there is no, ie. 0% Ring Loading

And here I prefer the term 'eye legs' - because only a loop can have a particular chirality (left-handed or right-handed) - the fixed eye of a knot does not have chirality (eg the eye of #1047 F8 has no chirality). Again - this is my theoretical view...
In any case, this type of loading profile has never actually been described in technical detail by knot book authors.
I had advanced the term 'axial loading' (and earlier - longitudinal loading).
In advancing such a term - it is simply discussion - it is not belligerent or offensive. The whole point of this section of the IGKT forum is to engage in technical discussions about theoretical knotting concepts (without fear or favor).

Yes, we have had this discussion at length before and I understand that you prefer to rename the loop as an Eye, equally, you will remember from our many discussions that my preference is to call a loop a loop.  However, it is my hope that you will be able to focus on the issue here as per your original post, of Ring Loading, and can perhaps put to one side what we each personally choose to call a loop in order to be able to concentrate on the aspect of exactly what is 'Ring Loading'.

I fully respect that the views you are promulgating are not intended to be " belligerent or offensive", and I equally expect that my own opposing views are not taken by your good self as being either belligerent or offensive.

As you know from our previous discussions, I never step beyond discussion about theoretical knotting concepts, and rely on you to execute our discussions without fear or favor in both directions.

When the loop legs are diametrically opposite, the subtended angle is 180 degrees and the knot is experiencing 100%, i.e. fully  Ring Loaded.

And here I would respectfully disagree in the application of therm 'ring' (which - in the ordinary dictionary meaning means a circle - or round).
I prefer to conceptualize this type of loading as transverse loading (and my earlier term was cross-loading in the radial direction).

Yes, I have read, as you previously posted, your preferred terminology.  However, simply restating it does not offer me any reason to change from my preferred use of the term 'ring'.  It is usual in discussion to offer alternative perspectives in order to sway a contra opinion, I am afraid a simple dictionary definition has no relevance to this highly specialised process and has not swayed my opinion.

All loop knots can experience Ring Loading (an angle subtended by the loop legs).

I would re-word this is follows:
The eye of a fixed eye knot can be loaded in a number of different directions as follows:
[ ] axial loading
[ ] transverse loading
[ ] circumferential loading
Again - in conceptualizing the loading profiles in this way - it is not an example of a mental deficit or a lack of professionalism or any form of belligerence. It is simply a discussion and an expression of views in accordance with the spirit of this section of the IGKT forum.

Of course, you have already stated exactly this before, and although simply restating your opinion does not offer any meat to this discussion, I do not take this to be a form of mental deficit or any form of belligerence.  As you say, this is a discussion and expression of views, which I respect and encourage your contribution to its furtherance.

I hope that you can now agree that Ring Loading is neither 'Ill defined' nor 'vague', and that the concensus of opinions are in agreement and at odds with your posted contentions.

I would like to express to you that I disagree - and that it is okay for me to disagree.
There is also an underlying tone in your narrative which does not accord with the spirit of this section of the IGKT forum.
For example, using sentence structure such as 'consensus of opinion' and... 'at odds with your posted contentions' - is using what I call 'social proof' to back your contention'.
The reference to 'consensus of opinions' isn't necessary.
You could simply state - my personal view is.... (enter your view).

I fully respect your right to disagree - it is after all the purpose of this forum to post and share opposing opinions.  However, as to your objection to my using the term 'consensus of opinion', I am offering it as a means of furthering discussion by offering it as a fact that at the current progression of this discussion, the majority of opinions posted are at odds with the opinion you are offering for discussion.  When only opinion is available and in the absence of facts, then I see no problem with reminding ourselves that your narrative does not meld with the numerous opinions held in contradiction to your own.

However, as I have previously stated, I find no problem with you holding a lone opinion, as sometimes the lone voice is the only one seeing the truth for what it is.  But in this instance, I think it is going to take a little more than simple repetition to sway others opinions and I look forward to following your further constructive discussions on this interesting subject.

Keep in mind what the purpose of the IGKT is.

I do not believe that we are discussing the purpose of the IGKT.  However, as one of the founders who pushed for the creation of this discussion board, I remain fully cognisant of its purpose, which I am certain we will all keep in mind.

[DDK]

I prefer to focus on the knot and describing the loading as offset.  If I were to test a loop knot for offset loading, there might not be a loop (let alone a ring) to be found.

[DerekSmith]

I totally agree DDK, the knot is not aware of what the cordage is doing beyond a cm from its entry point, it only knows the force and directional vectors as they enter the knot.  Whether the cord is attached to a loop, or an anchor a kilometer away is of no interest to the knot, so we should disregard how the cord obtained its force and directional vectors and concentrate only on how they affect the knot.

[agent_smith]

Mark, I totally applaud your right to hold a view different from mine (and from the majority of other posters) - indeed, sometimes the lone voice can even be right...

And here I see (again) the use of language that is completely unnecessary.

the majority of opinions posted are at odds with the opinion you are offering for discussion

Hmmm - social proof again.
Derek, there is a very small audience (in comparison to the entire world).
And some of this very small 'audience' have been warned by the moderator to desist from personal attacks.
The English language is complex and it is possible that the word 'ring' is understood and conceptualized in different ways.
To be clear - I understand the word 'ring' to be a thing of circular or round shape.
Eg a ring that is worn on a finger, a circus ring, the symbols of the Olympic games - in my view, are all circular in shape.

I also note that the concept of change can evoke strong feelings in some individuals - and in some cases, trigger outrage. Clinging to terms published by Ashley (published some 75 years ago) may not be as relevant today as is was then. Some concepts were assumed or implied - probably because of deep tradition.
For me, I embrace change and do not fear it.

And for me, if a person says; "Heh, ring load that eye knot"
My response would be - "Can you be more specific please?"
"In which direction would you like me to 'ring' load that eye?"

However, as I have previously stated, I find no problem with you holding a lone opinion, as sometimes the lone voice is the only one seeing the truth for what it is.

I had to chuckle at your use of certain language (again).

Actually, while pondering my assigned 'lone' status - I might post a quiz for you - with images of various loading profiles on the eye of a fixed eye knot. You would have the (lone) option of providing answers.

However, it is my hope that you will be able to focus on the issue here as per your original post, of Ring Loading, and can perhaps put to one side what we each personally choose to call a loop

Actually, the concept of an eye is pertinent to the broader understanding of how it (the fixed eye) can be loaded.
The eye of a fixed eye knot has no particular chirality.
So when I am load testing (a fixed eye) I wont have to repeat the tests for an 'S' chirality eye and then a 'Z' chirality eye (because it doesn't exist).
I could load the fixed eye in a transverse direction - so that the SParts are isolated from load - and the legs of the eye are loaded in opposition (although this is not quite 'offset' loading as would occur with a 'bend').
Or, I could apply a circumferential load - to expand the eye in multiple directions simultaneously. In this case, the SParts are not completely isolated from load.
If I load the eye axially (longitudinally with respect to the SPart) - the SPart is maximally loaded - and both legs of the eye are subjected to 50% of the load in parallel.

I do not believe that we are discussing the purpose of the IGKT.  However, as one of the founders who pushed for the creation of this discussion board, I remain fully cognisant of its purpose, which I am certain we will all keep in mind.

No - you misunderstood my point - although I could have worded this better.
I meant this IGKT forum - this very section of the forum - where people can engage in technical/theoretical discussion.
Although I have found (from past experience) that you sometimes have difficulty in remaining polite and avoiding thinly veiled comments that are intended to devalue or denigrate opposing views.

Part of my underlying reason for wanting to commence discussion (apart from the high probability that the term 'ring' loading was originated in this forum or via certain individuals inhabiting the IGKT forum) - was due to the 'Mobius Butterfly'.
This derivative of #1053 Butterfly has some very interesting properties and is also 'TIB'.
It appears that this particular fixed eye knot can be loaded in a number of different directions with impunity.

...

One thing I really like about this IGKT forum is that the moderators are quick to call out bad behaviour (unlike in other social forums). There is guardian angel watching over this topic thread..

Typos corrected...

[DerekSmith]

Mark, I refuse to be drawn into a sensless heated argument with you by your use of implied threats.

To draw this discussion back to the issue at hand, I will reiterate my previously stated ten points.  If you have any arguments or perspectives that might be useful to help me consider an alternative opinion, then I would appreciate reading them, but I do not wish to see any further off topic innuendo, or implied threats of divine retribution.

1. Ring loading is a simple and well understood term which has a single variable aspect.
2. There are not 'classes' of Ring Loading, but there are degrees of Ring Loading.
3.  Fixed Loop knots are cordage Force Machines which transpose and translate forces between the loop legs and the primary load bearing SP.
4.  Ring Loading is defined by the angle subtended by the two loop legs.
5. When the loop legs are parallel, the subtended angle is zero and there is no, ie. 0% Ring Loading.
6.  When the loop legs are diametrically opposite, the subtended angle is 180 degrees and the knot is experiencing 100%, i.e. fully  Ring Loaded.
7. When the loop legs subtend and angle of 120 degrees, both loop legs and the SP are potentially subjected to equal tension loads.
8. At subtended angles above 120 degrees, the forces required in the loop legs needed to balance the SP load, rise exponentially to multiples of the applied SP load.
9. All knots respond to applied forces, some are capable of resisting change, while some are liable to capsize.  By way of example, THE Bowline is reasonably stable to low levels of Ring Loading ( ca 20 degrees and less), but is at high risk of failure at high levels, while other knots such as the Carrick Loop retain their stable structure.
10. All loop knots can experience Ring Loading (an angle subtended by the loop legs).  To factor this into our knot usage, we need to be cognisant of the impact of divergent force vectors and be familiar with the response our knot structures have to applied loads.

Derek

[SS369]

Gentlemen, we are getting repetitive and basically going nowhere.
Terminology has been a bane of this society for a long time and I?m not sure that a consensus is forthcoming.
I personally feel that more distinct descriptors can help with the describing and defining of a fixed eyeloopring that is loaded.
One can describe how the loading(s) can and will effect the core and what may happen during loads that are not evenly applied either slowly or with sudden jerks.
We must remember that quite a few members that come here are not knot efficienados and can learn what the common parlance means via pleasant discourse.

So, please notch it back a bit and help others to understand better as we travel this path.

SS369