KNOT TESTING GUIDELINES - is IGKT best positioned to set fundamental guidelines?

Knotting Concepts & Explorations
1

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

2

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!).

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 --[i][u]The Encyclopedia of Knots & Fancy Ropework[/i] by "Hensel & Gretel" being maybe the king of crap!
I am saying that we, as a [u]knot tying community[/u], 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) ::

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
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", [i][u]The Ashley Book of Knots[/i] !)

“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.

> He commented that we do not need more 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,
    What is the strongest sailing knot?
    ! --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*

3

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

4

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

5

From NautiKnots:

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

6

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.

7

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.

8

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?

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.
Pulling knots to failure (by itself) is not and should not be the [i][b]sole [/b][/i]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.
If I wanted to test #1410 offset overhand bend, I would find little information from these institutes that would guide me in [u]how [/u]and [u]what [/u]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.

9

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?

10

Then I am afraid I cannot help you.

Either you are on a campaign to declare that; "No, the IGKT is [u]not [/u]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. [ol]- 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 [I]is[/I] very knowledgeable about knots, but not about testing. If one wants to give useful guidance on knot testing, one will need to understand both. [/ol]
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 [I]are[/I] 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.
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.
11
Then I am afraid I cannot help you.
Your alleged 'help' is misplaced.
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...
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. [b]You asserted that there were none[/b].
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.

12

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.

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 "[b][I]KNOT TESTING[/I][/b]" requires both knowledge of [b][I]KNOTS[/I][/b] and knowledge of [b][I]TESTING[/I][/b]. 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.

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 [I]examples of test methodology[/I], or aren't they?
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.
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?
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: [ol]- 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?[/ol]

Because #2 is all I’ve ever suggested.

13

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

14

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.

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 :

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*

15

Right. It might be that, in continued deliberations
here, we draw out many test-method desiderata
[where’d I draw THAT words from! ::slight_smile: ]
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*

16

My original concept and purpose behind starting this thread was to mobilize a concerted effort to address the shortcomings and failings of knot testing and reporting of results.

I maintain and reaffirm that there is no current body or entity that a knot tester can turn to for advice in the following:
knot naming conventions
knot form and structure (geometry) - ie getting the dressing correct for a particular knot species
what to test - eg rather than the default pull-to-failure mindset that permeates the entire sub-culture
use of appropriate control knots to draw comparisons against

NautiKnots source of continued irritation is linked to his belief that current institutions (eg cordage institute USA) already address statistical sampling methods and proper use of tensile (force) generating machines so that testers can obtain reliable results.

But this misses the point entirely.

There are principally 3 distinct forms of testing carried out:

  1. Hobbyist/enthusiast style testing done by interested individuals who largely act in isolation. This type of setup is not a business enterprise. It is typically conducted at the testers home (but it could be carried out in a garage/shed or even the persons backyard).
  2. Semi-formal testing done in a non-certified lab with mechanised equipment and is generally done by individuals who hold themselves out as possessing an expertise. This type of setup is sometimes a business enterpise - eg rope access and/or vertical rescue business enterprise.
  3. Formal testing done in a certified lab in accordance with their accredited procedures - but the individuals behind the tests are typically lab technicians first and knot enthusiasts last. This type of setup is usually a business enterprise.

I think NautiKnots source of irritation is linked to #3. In a formal certified test lab - everything is done in accordance with strict protocols. There is specialised force generating equipment that is carefully calibrated - and an environment that is purpose built to carry out a range of destructive style testing.

In #1 above, funds are typically very limited and so is spare time. There is no formal environment in which to operate. There is no strict use of calibrated force generating instrumentation.

In #2 above, usually the tester(s) have access to more funds and may have setup a pseudo lab. A good example would be ‘Rope Test Lab’ run by Richard Delaney in NSW Australia. He is a roping enthusiast but his ‘lab’ is not ‘certified’ as such. Within Australia, such lab certification is typically done through ‘NATA’ (National Association of Testing Authorities). Note that ‘NATA’ is not specifically knowledgeable about knots and knot structure. NATA is about setting up a test lab so it can test articles consistently and reliably to a certain standard.

This is largely what the cordage institute is.
It is not specifically knowledgeable about knots and knot geometry. Its more about measurement and pulling test articles to failure. Although the word ‘cordage’ is embodied in the title, this has more to do with cord/rope construction rather than knot tying.

And this is where NautiKnots source of irritation comes from.

As it currently stands, well funded knot testers could turn to a certified lab and request a set of tests (for a fee). The certified lab would not have any expertise on how to tie the knot specimens or what to test. This would be the responsibility of the individual who hires the use of the lab facility for a fee.

In Richard Delaney’s case, he is not a certified lab - but, he does have a pseudo lab environment and access to motorised force generating equipment. Richard would not turn to ‘NATA’ or the ‘Cordage institute’ for advice when testing. This is because ‘NATA’ and the ‘cordage institute’ do not possess specialized expertise in how to tie knots and what to specifically to test.

Whilst I have due respect for testing authorities such as ‘NATA’ and the ‘Cordage institute’, these entities do not possess specialised expertise in knot tying.

Hopefully, Nautiknots irritation will subside, now that I have clarified that testing authorities do not possess specialised expertise about knots and knot tying. These entities focus on reliability of test methods and the machinery that produces the tensile forces. And it is all based around the mindset of ‘pull-to-failure’. If I contacted the Cordage institute and asked them;
“How do I tie and test the Offset overhand bend?”
Their response would be; " " (blank).

Remember that all entities and authorities consist of people (humans like you and me). It is the people that comprise the entity. Merely because an entity carries a title such as ‘NATA’ or ‘Cordage institute’ or ‘IEEE’, does not by itself automatically grant expert level knowledge about knot tying.

17

This is my attempt at shifting into 1st gear - in order to cease spinning wheels and going nowhere.
Note that this is only 1st gear - but at least its a start.

And so… I propose the following as a basic framework for knot testers and aspiring knot testers.
This shouldn’t be too onerous / difficult to achieve.

KNOT TESTING GUIDELINES (A basic framework)

Checklist:

[ ] Determine the purpose of your test
eg; to determine the MBS yield point (ie load at which the knot breaks) or to investigate something else? (eg at what load does the knot jam or, at what load is instability triggered or, which dressings improve or lessen stability?)
- if you are of the ‘pull-to-failure’ (ie break it) mindset, ask yourself “why?” Why is it important to pull your knot specimen to failure?
- what are you trying to prove?
- is ‘pulling the knot to failure’ really going to conclusively prove anything? (note that harness tie-in knots dont break when you take a lead/climbing fall…there is no force that a falling climber can generate that will break a knot. Your climbing rope is more likely to fail due to cutting/sawing over sharp edges). Even in highlines, where the line tension is maxed out, still doesn’t break knots. In this case, your anchors are more likely to fail or yield. If you are of the general population mindset that pulling knot ‘A’ to failure against knot ‘B’ to failure proves superiority of one compared to the other - you should re-think your proposition!

[ ] Determine the type of cordage/rope that you will use for the test
- this is crucial. The type of material plays a significant role in how the knot will respond to load.
- slippery materials such as ‘dyneema’ will behave differently to regular EN1891 certified low stretch abseil rope
- what diameter cordage/rope will you use? The larger the diameter, the greater the force required to reach its MBS yield point
- maybe you want to use 2 different rope diameters (eg a ‘end-to-end’ joining knot to see how it responds to increasing load)
- are you testing ropes that conform to an EN standard? (eg EN 892 dynamic climbing rope)
- is it imperative that you test human-rated ropes that conform to a standard? (eg EN 1891, EN 892, etc)
- is your rope/cordage in brand new (unused) condition? Or is it aged? If aged, how old?
- either way, it is important that you are very clear on exactly what type of rope/cordage you are using

[ ] What type of test facility are you?
- I am a ‘backyard’ tester. I do not have any sophisticated test apparatus. I am not well funded and I don’t like math (ie statistics).
- I have a pseudo test lab. It is not a certified lab but, I do have access to force generating equipment and limited funds.
- I am a certified nationally accredited test lab. I have calibrated force generating equipment and computers to measure and document results. I am reasonably well funded.

NOTE: The level of expectation [i]scales [/i]according to which test category you fit within. If you are a 'backyard' tester, we are not going to criticize you for failing to use calibrated digital instrumentation and avoiding hard statistical mathematics!

[u] Check in at the IGKT website/forum and run your test idea there.
- although full of nerdy knot enthusiasts, the IGKT has some exceptionally talented individuals who have unique insights into all things knot related. They can provide expert level advice all free-of-charge.

[ ] Use appropriate naming conventions for your knot specimen so it can be properly identified
eg; Where possible, use ‘ABoK’ reference numbers.

[ ] Pay close attention to knot ‘dressing’ (ie form and structure)
- dont be sloppy - be ruthlessly accurate in getting the dressing correct!
- diligence is the key

[ ] Photograph your knot (before, during and after your load test)
- take your photos against a plain while background…eg, use a plain white bed sheet as a background for your photo
- make sure all segments of the knot structure are visible in the image (including the ‘tail’ end)

[ ] Repeat your test several times to obtain a reasonable statistical sample (ideally, at least 5 repeats)
- breaking or jamming knots costs money - we know this. Keep in mind that a test sample of ‘1’ is not sufficient to draw any conclusions…you need to do more than just one test.

[ ] Use a ‘control’
Try to be ‘scientific’…all good science testing uses what is known as a ‘control’.
Link to info about scientific ‘controls’: https://en.wikipedia.org/wiki/Scientific_control

[ ] Measure the force that you are applying to the knot
- try to use force generating equipment that has a ‘gauge’ so you know how much tensile force you are applying
- digital is best but, if you only have an analog gauge then this will suffice.

[ ] Report your results
- make sure you write a conclusion

…

Mark Gommers

18

i don’t approve of road racing, but see pro-racing as measurement, competitive development; that in end drives us forward.
i think strength tests are good, but not total purpose, just benchmarks and expanded understanding as we groom the mechanics.
.
Standardization would be good, nice list, but wouldn’t throw away thoughts and observations of the mentioned testing associations;
to get their experiences as well as draw them into helping mature this, and then also adhering and leading with it.
.
i think that safety awareness should be part of this; as pushing knot to ‘explosion’ especially if metal link is attached can be hazordous to people, expensive testing gear etc.
.
i liked Eric22 / alan_lee’s http://igkt.net/sm/index.php?topic=6120.msg41258#msg41258

shows deformities, changes, damage to line >> data is data, and seeing what really happens makes so well makes simpler watching more tangible and intuitive.
perhaps anti-climatic w/o knot explosion, but still many lessons shown >> data is data
and safer to walk to edge and not jump off, knot explosion could have been injurious, taken out measuring device etc.
should look to have safety guidelines, suggestions if not just warnings
.
i think several tests and different materials done at same time /circumstance / tester
in playing around when could, i have made eye to eye sling with different Bowline’s
one of the things testing is tail in eye or not >> 1 Bowline of each on ea. end of sling to same type carabiners pulled by truck
different materials seem to break earlier on the ‘innie’ and others on the ‘outie’ side of the home-made sling
no meter, just who fails first: the most direct Nip of ‘outie’ missing Bitter End or w/less directness but more primary force on both parts of final turn around SPart of ‘innie’.
.
i’m all with observing the proper geometries, as really the most key concept anyway
and think naming or at least family groups should be formed by respect of such geometries and force flow thru them.
but for reachability outside to the masses, some groupings by type of usage are necessary; or at least need to be allowable.

19

No, you missed my point entirely. I never promoted the use of tensile strength as a useful measure of knots. Nor did I ever say that the Cordage Institute is a source for information on knots. Now you are the one trying to put words in my mouth and your assertions are utterly false.

ALL my statements were about testing methodology and statistical significance, not about what tests were being performed, nor about what tests should be performed. I simply said that although the IGKT is skilled at knot tying, it is not skilled at designing consistent, repeatable, and statistically significant tests, and could learn from the exmaples of others.

At this point, you have exhausted my desire to participate, so I have stopped following this discussion. You need not worry about further posts from me. I simply leave you with this food for thought:

If you truly want to be a “key player” in setting standards for knot testing, is it really wise to begin by summarily dismissing all published work by

[ol]- the de-facto standards body of the cordage industry, and

  • the world’s largest association of technical professionals?[/ol]

Do you really believe that you know more about how to construct scientific tests than they do? Good luck – I have little faith in your success.

Regretfully,
Eric

20

NautiKnots,

I think you have a strong desire in wanting to defend yourself in relation to some imagined proposition.

And your desire to defend appears to be linked to your belief that methodology established by testing authorities is very important - and should not be ignored.

There is no intent to extinguish existing methodology established by ‘testing authorities’. To the contrary, they are complimentary and should coexist with these established testing methodologies.

Dont forget the 3 different types of testers:

  1. Backyard type testers who largely act in isolation
  2. Pseudo lab testers (eg Rope test lab…Richard Delaney)
  3. Accredited/certified testing labs with calibrated equipment and measurement recording devices.

Expectations and accuracy scales according to each type of tester.

For example, I think it would be unreasonable to hold a ‘backyard tester’ to the same level of rigor as an accredited and certified test lab. In contrast, we would expect an accredited, certified test lab to produce scientifically valid test results.

Perhaps your views re consistency, and collecting statistically valid test data is aimed largely at accredited, certified test labs and (possibly) pseudo test labs?