Author Topic: KNOT TESTING GUIDELINES - is IGKT best positioned to set fundamental guidelines?  (Read 3117 times)

agent_smith

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There has been a reasonable volume of forum discussion about knot testing and indeed, criticism of existing knot test reports.

I have noted that there appears to be a vanishingly small volume of test reports that actually can be regarded as authoritative with relevant and meaningful data.

It seems that, more often than not, knot testers seem to repeat the same old tired mistakes and report data that is either misleading or somewhat irrelevant.

One has to ask the question; "Why?"

...

So I have been giving this matter some thought and I believe that the IGKT has to accept some of the responsibility for this recurrent issue. I am not pointing the finger at any one individual - I am saying that we, as a knot tying community, should have addressed this issue long ago.

We have some really clever people in the IGKT - and there is a remarkable body of knowledge and advancement of the science of knotting - all due to the IGKT.

But, for one reason or the other, when it comes to knot testing and reporting, we seem to lack motivation and focused energy to take a leading role in developing a set of guidelines for knot testing and reporting of results.

At this stage, I am simply asking the question; "Why?"

I guess the question that follows from this is; "What can we do about it?"

...

Mark Gommers
02 July 2018


Dan_Lehman

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There has been a reasonable volume of forum discussion about knot testing and indeed, criticism of existing knot test reports.
I'd say that the volume is more hot air than substance,
which was my point to urging precise comments in the
recent/current thread about a Yachting Monthly article
reporting some rather lame testing.
.:.  We need to keep generating such pointed criticisms,
trimmed by internal debate & Occam's razor, to become
a set of guidelines for future testing (and for appraising
extant test reports!).

Quote
It seems that, more often than not, knot testers seem
to repeat the same old tired mistakes and report data that is
either misleading or somewhat irrelevant.
One has to ask the question; "Why?"
The same question is raised by knots books parroting
the same old nonsense over & over & over, often in
incredible cases --The Encyclopedia of Knots & Fancy Ropework
by "Hensel & Gretel" being maybe the king of crap!

Quote
I am saying that we, as a knot tying community,
should have addressed this issue long ago.
Sometimes it seems to me that this imaginary
community is ascribed to those of more *real*,
active communities (angling, caving, e.g.) who
happen to focus on knots --but often rather
parochially vs. broadly.  And the *broad*-minded
interested parties haven't been good at collecting
the widespread/disparate information and trying
to make sense of it all.

E.g., I am abashed to say that I've not built a list
of extant test reports --an easy thing to refer to.
... lazy ..., "do it sometime (later) ... " ?!
Well, SOMEone has done a bit of this --to wit
(news to me, which I captured w/these remarks)  ::
Quote
Finding a rich lode ?!
Here's the overview, which has citations of so many others!
http://itrsonline.org/wordpress/wp-content/uploads/2016/11/Evans_Truebe.A-Review-of-Knot-Strength-Testing_2016.pdf

Quote
there is a remarkable body of knowledge and
 advancement of the science of knotting - all due to the IGKT.
What advancement do you see?
(I see that in the pre-latest (#138?) Knotting Matters there is
still parroting of the obviously overinflated "knots" count
for our "bible", The Ashley Book of Knots !)

"What can we do about it?"  --see above.
(And maybe a thread for it, perhaps awaiting first
a good set of things to capture in the thread's OP
--so let's run a bit on the comment-&-critique bit
prior to establishing a thread on testing.)

Here's my reaction to the above-linked collection
of test reports.

Quote
>  He commented that we do not need more <knots> testing,
>  but a synopsis of the data already available.

It's great to be looking over the seemingly vast
knots-testing-literature field and trying to make
some sense of it.  But this survey overlooked a
couple of key criticisms of this vastness :

1) test reports seldom show the exact knot/geometry tested
(and common literature is usually pretty vague on such detail
--e.g., in MANY instances, the fig.8 eye knot (nevermind the
pretended distinction of "on a bight"/"rewoven") is shown
only with both ends going out of view, and so no indication
of which should be loaded, which the tail (!).

2) testers don't all have very good knotting skills and tie
things haphazardly.
(A shockingly bad case just came to light for me,
www.yachtingmonthly.com/sailing-skills/strongest-sailing-knot-30247
!  --i.p., note their fig.8s !  Egadz, ...)

So, sadly, a survey of much knots testing is a dive into
muddy waters; much of the stuff is pretty worthless, IMO.
And it would be nice to get some better ideas of WHERE
--which should lead to theories of Why-- knots break.
(In the aforementioned Yachting Monthly report, it is
MOST peculiar to see a fig.8 eye knot breaking in one
of the eye LEGS --I can't raise a theory to figure this! ??



Cheers,
--dl*
====
« Last Edit: July 03, 2018, 09:34:58 PM by Dan_Lehman »

agent_smith

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Please read this very carefully before hitting the reply button!

Of all the current and future knot testers in the world; where do they go to find one coherent and clear set of instructions to guide them in their knot testing efforts and report writing?

At risk of pressing this issue to hard - is the IGKT best positioned to take the initiative and address this matter?

I acknowledge and understand that the IGKT is a loosely cemented community - with no particular agenda to solve this matter.
However, we do have on board a few very talented individuals who do possess very specialized and technical level knowledge about this subject.

QUESTION: As it currently stands, knot testers such as Thomas Evans, Grant Prattley, Dave Richards, Richard Delaney; The various would-be testers from Climbing and Yachting magazines; et al - where exactly do they go to find information to guide them?

ANSWER: Nowhere! There is nowhere to go and there is nothing to guide them other than their own personal view of how to test and report.

QUESTION: Just because 'we' (ie interested members of the IGKT) can assist the knot testing community, does that mean 'we' should?

QUESTION: Who actually cares?

QUESTION: Should 'we' do nothing - and just allow the present status quo continue?

QUESTION: Am 'I' (ie the individuals reading this post) prepared to do something to alter the current status quo?

...

Mark Gommers

NautiKnots

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...where exactly do they go to find information to guide them?

ANSWER: Nowhere! There is nowhere to go and there is nothing to guide them other than their own personal view of how to test and report.
The Cordage Institute and the IEEE would be good sources to search for testing procedures of cordage and knots.

agent_smith

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From NautiKnots:
Quote
The Cordage Institute and the IEEE would be good sources to search for testing procedures of cordage and knots.

No they aren't! (And this could be a source of irritation to you when you read this). These entities wont be able to explain 'what' to test. Do not misunderstand my meaning...I do like testing authorities and I like the cordage institute. They do valuable work. However, they are not knotting experts - knot tying is not their core business.
For example, if I contact the cordage institute and asked them; "How do I tie and test the offset overhand bend?" - they will not be able to respond.

Can you show me exactly where they describe in detail how to tie and test knot specimens in order to produce relevant and meaningful data?

I think you are confusing MBS break testing of ropes and cordage with physically tied knot specimens.
The cordage institute do not publish documents that specifically deal with knots, knot geometry and loading profiles of knots.

Here is a link to fibre rope testing from cordage institute: http://www.ropecord.com/cordage/publications/docs/CI1500.pdf

« Last Edit: July 06, 2018, 01:08:36 PM by agent_smith »

NautiKnots

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That's a pretty quick summary dismissal.

I didn't say anything about any specific tests performed, nor about what they attempt to determine, merely that these two organizations' publications would be worth searching for topical research.

For example, https://ieeexplore.ieee.org/document/6859564/, in which the researchers used a knot-tying machine in order to assure the uniformity (and, presumably, correctness) of their test samples.

agent_smith

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I am concerned that the concept behind my original post is going to bog down and evaporate.

NautiKnots - your bringing the cordage institute and IEEE into focus is appreciated but in the end - of no actual use.

These organizations do not publish technical information about knot structure and form - they focus on the machinery that produces a force and the accuracy of testing/sampling methods.

Can you not see this?

For example, lets say I wanted to test #1410 Offset overhand bend.

These institutes wouldn't know anything about the following:
[ ] effects of rotation
[ ] where to position different diameter ropes within the knot structure
[ ] correct use of naming terms (eg 'offset' versus 'flat' or 'one-sided')
[ ] jamming threshold
[ ] instability threshold
[ ] low stretch versus dynamic ropes
[ ] use of ABoK numbers to positively ID a knot

Same goes for any other knot you can think of...eg #1053 Butterfly eye knot.
These institutes wouldn't know or publish information about 'eye loading' versus 'through loading' versus different dressings (eg crossing the SParts as they enter the core versus parallel SParts etc etc.

These institutes tend to focus on dry technical information that pertains to the tensile force producing machinery, statistical sampling methods, pure MBS break testing, and accuracy of reporting. It is generic in nature and not specific to knot geometry. Pulling knots to failure (by itself) is not and should not be the sole focus of testing!

If I wanted to test #1410 offset overhand bend, I would find little information from these institutes that would guide me in how and what to specifically test.
« Last Edit: July 03, 2018, 05:14:47 AM by agent_smith »

NautiKnots

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These organizations do not publish technical information about knot structure and form - they focus on the machinery that produces a force and the accuracy of testing/sampling methods.
Perhaps you'd be more interested in Feasibility of Knots to Reduce the Maximum Dynamic Arresting Load in Rope Systems.  This paper is an introductory exploration of how a select few knots affect shock absorption and tensile strength in Technora cordage under dynamic load.  It is specifically aimed at fall-arrest systems for climbing and safety use.  Is this not the type of study you're hoping to see?

Quote
These institutes tend to focus on dry technical information that pertains to the tensile force producing machinery, statistical sampling methods, pure MBS break testing, and accuracy of reporting. It is generic in nature and not specific to knot geometry.
Are you saying that testing technique, accuracy, and statistical sampling methods are unimportant?  If so, I disagree. 

Quote
Pulling knots to failure (by itself) is not and should not be the sole focus of testing!
I agree, and have repeatedly said so myself.  Before setting out to "test knots", one should first state what one hopes to learn, and then construct test(s) that will yield the desired information in a meaningful way.

Quote
If I wanted to test #1410 offset overhand bend, I would find little information from these institutes that would guide me in how and what to specifically test.
But you will find lots of information about testing standards, and about how others constructed and performed their experiments in order to produce repeatable, statistically significant results that can be extrapolated to real-world applications.

Yes, it is meaningless to perform statistical analysis on knot tests if you don't know how to tie the knots.  But, it is also meaningless to perform statistical analysis on knot tests if you don't understand testing methodology or statistics.

agent_smith

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NautiKnots,

I am dumbfounded by your posts.

Either you are on a campaign to declare that; "No, the IGKT is not the entity to play a key role in guiding knot testers"; or, "Allow the present status quo to prevail"; or "the cordage institute and IEEE are already addressing the issues I have raised and therefore it is a non-issue"; or some other agenda which is obscure to me.

Your link doesn't work:
Link: https://link.springer.com/article/10.1007/s40870-015-0015-5
And what exactly are you trying to prove with this link?
This paper examines the use of knots as mechanisms to reduce the impact force of a fall.
In the paper, the F8 eye knot (#1047) is poorly dressed.

Again - why did you post this link? What are you trying to prove? And why?

I am wondering if you actually understand the nature of the issues I have raised?

NautiKnots

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I am dumbfounded by your posts.
Then I am afraid I cannot help you.

Quote
Either you are on a campaign to declare that; "No, the IGKT is not the entity to play a key role in guiding knot testers"; or, "Allow the present status quo to prevail"; or "the cordage institute and IEEE are already addressing the issues I have raised and therefore it is a non-issue"; or some other agenda which is obscure to me.
I choose Option 3. 
  • I think the IGKT can play a key role in guiding knot testers.
  • The Cordage Institute and IEEE are not knot testing institutions (to be more general, I'm not aware of any institution dedicated to testing knots - IGKT included).
  • I think it's wrong to say that there is nothing to be learned from the CI or IEEE (or other journals).  They may not be big on knots, but they are big on rigorous, scientific testing.  The IGKT is very knowledgeable about knots, but not about testing.  If one wants to give useful guidance on knot testing, one will need to understand both.

Quote
Link: https://link.springer.com/article/10.1007/s40870-015-0015-5
And what exactly are you trying to prove with this link?
Again - why did you post this link? What are you trying to prove? And why?
I'm just pointing out that there are people out there testing knots in rigorous ways and publishing their methods in peer-reviewed scientific journals.  You asserted that there were none.  I think (if one wants to test knots) one could learn about accepted testing methods from published examples.

Quote
I am wondering if you actually understand the nature of the issues I have raised?
Apparently, neiher of us understands what the other is saying, so I'll leave it at that.

agent_smith

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Quote
Then I am afraid I cannot help you.
Your alleged 'help' is misplaced.

Quote
I think it's wrong to say that there is nothing to be learned from the CI or IEEE (or other journals).
I think you are misguided and imagining things that you think I stated, which I did not.
I think you are motivated by something you imaged in your mind. Hmmm, there is something behind all this...

Quote
I'm just pointing out that there are people out there testing knots in rigorous ways and publishing their methods in peer-reviewed scientific journals.  You asserted that there were none.
I am again dumbfounded by your proposition.
Do you really imagine that I am unaware of all the existing knot test reports?
I never stated this imagined assertion.
Of course there are people doing knot testing! And of course there are existing knot test reports.
I stated that current/existing knot test reports are often drawing incorrect conclusions or testing aspects of knots that are irrelevant or misleading. Many typically focus on pure MBS knot yield (ie pure pull-to-failure mindset).

Which part of what I am stating are you struggling with?

I am aghast at your stance on this matter, and it leaves me wondering if other IGKT members feel the same way?
Sadly, I think the future of knot testing is at risk of staying on its present heading.

NautiKnots

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Quote
I think it's wrong to say that there is nothing to be learned from the CI or IEEE (or other journals).
I think you are misguided and imagining things that you think I stated, which I did not.
Ok, I said:
"The Cordage Institute and the IEEE would be good sources to search for testing procedures of cordage and knots."

And you replied:
"No they aren't!"

Please explain exactly why you said they are not good sources to search if there IS something to be learned from them.

Quote
I think you are motivated by something you imaged in your mind. Hmmm, there is something behind all this...
All I've ever said, is that meaningful "KNOT TESTING" requires both knowledge of KNOTS and knowledge of TESTING.  This community is already quite familiar with knots.  I propose that if the IGKT wants to give advice on knot testing, that it learn about testing as well.

I don't know where this vitriol comes from.  I have made no personal attack on you whatsoever.  On the contrary, I have great respect for your knotting expertise and I find this discussion quite distressing.

Quote
I am again dumbfounded by your proposition.
Do you really imagine that I am unaware of all the existing knot test reports?
I never stated this imagined assertion.
Of course there are people doing knot testing! And of course there are existing knot test reports.
Ok then, please reconcile this statement with your above comment (of "No they aren't!").  Are these peer-reviewed publications worthwhile examples of test methodology, or aren't they?

Quote
I stated that current/existing knot test reports are often drawing incorrect conclusions or testing aspects of knots that are irrelevant or misleading. Many typically focus on pure MBS knot yield (ie pure pull-to-failure mindset).
A statement I agree with, but which has no bearing on what I've tried to say about test methodology and statistical significance.

Quote
Which part of what I am stating are you struggling with?
Well, to be honest, I'm struggling with your reaction to my statement that before designing our own test procedures, we should be familiar with how Industry Standards organizations perform tests.  Not what specific tests they run, but how testing is validated in general, so we can have confidence that our test results correspond to real-world knot behavior.  Why are you so upset about that?

Quote
I am aghast at your stance on this matter, and it leaves me wondering if other IGKT members feel the same way?
I am at yours as well, when I think we should actually be in agreement on this.  Wouldn't you agree that:
  • When knot tests are performed, that the knots must be properly tied, dressed, and set?
  • When knot tests are performed, that the testing must be consistent, reproducible, and statistically significant?
Because #2 is all I've ever suggested.

SS369

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So, let's say someone finds a test facility, has a camera, has some selected rope (maybe various dimensions?) of the same construction/materials and wants to invest some life to run some tests. What list of procedures, protocols, etc., etc., can they use that the results won't be systematically poo-pooed or nitpicked?

Backyard or field testing and even some of the sources online of tests gone by are regularly picked apart for one thing or another here.

If we have an agreed upon check and set up list, then it makes sense to to do the investment. That is what I hope to see this thread develop into.

SS

Dan_Lehman

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The Cordage Institute and the IEEE would be good sources to search for testing procedures of cordage and knots.
I got some stuff from the former, and it impressed me
as overly attentive to less important things than I'd want
to see.  In any case, while there are some standards for
knot testing regarding pull rate and so on, there aren't
similar for tying the knot --e.g., a given specification
for dressing the fig.8 eye knot and which end to load.
(CE/UIAA I think specify a test method for dynamic ropes
which demands such a knot, but there there is no like
spec. for the knot itself (and even how long its eye should
be for those tests).

"ISO/TC 38/WG 21, Ropes, cordage, slings and netting, Working group"
is a subset of ISO's Textiles body, and is the place for some
international standards.
Quote
Standardization of :
fibres, yarns, threads, cords, rope, cloth and other fabricated textile materials;
and the methods of test, terminology and definitions relating thereto; ...
The Cordage Institute operates in some bit of American independence
of that, or at least as a competing standard.  (As I mentioned elsewhere,
I recall that one body defined  advertised tensile to be determined
by eye splices --so, they are by def. 100%--, whereas some
other standards allow other ways to figure this value (which
would give then a way to evaluate the eye splices).

Looking for such things under USA's "ANSI", I find :
Quote
Founded in 2003, the Professional Ropes Course Association (PRCA)
became the first industry association to achieve the ANSI Accredited
Standards Developer status in 2005.  On March 3, 2014, ANSI designated
the ANSI/PRCA 1.0-.3 2014 as the sole ANSI American National SAFETY
Standard (ANS) for Challenge Courses, Ziplines, and Aerial Adventure Parks.
This standard covers both participants and employees.  Accordingly,
the ANSI Essential Requirements outline that no other conflicting or
duplicating ANS should be allowed.
The mission of the PRCA is to develop end-user applicable standards,
documents, and to define, document and outline the construction /
operational practices for the Ropes Challenge Course, Zipline,
and Aerial Adventure Parks industry.
There are probably some words re knots in this.

And there is this, for arborists:
ANSI Z133 Safety Requirements for Arboricultural Operations Manual


--dl*
====

Dan_Lehman

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If we have an agreed upon check and set up list,
then it makes sense to to do the investment.
That is what I hope to see this thread develop into.
Right.  It might be that, in continued deliberations
here, we draw out many test-method desiderata
[where'd I draw THAT words from!  ::) ]
from which various subsets are made as best fits
--perhaps within cost or time or ... constraints--
the particular needs of a tester consulting with IGKT
about testing.

(E.g., for someone keen to test some abseil-rope joints
with strength-testing in mind, the advice might be to
test for some significant but non-rupture forces and
to evaluate in some more meaningful way.
Otherwise, to be able to refer the tester to good images
& specifications for tying a knot.)


--dl*
====
« Last Edit: July 05, 2018, 10:59:36 PM by Dan_Lehman »