Author Topic: Tokyo Olympics boulder climbing knot  (Read 903 times)

SS369

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Re: Tokyo Olympics boulder climbing knot
« Reply #15 on: September 14, 2021, 02:08:22 PM »
Please All, let?s get back on and stay on topic.

SS369

DerekSmith

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Re: Tokyo Olympics boulder climbing knot
« Reply #16 on: September 14, 2021, 05:17:47 PM »
Hi Scott,

Yes, I made my apologies to the OP, but the topic of testing protocol really does deserve its own thread, so I will 'Cease and Desist', particularly as I find Mark's persistence in editing quotes well out of order.

Thanks for your commitment.

Derek

agent_smith

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Re: Tokyo Olympics boulder climbing knot
« Reply #17 on: September 14, 2021, 10:29:57 PM »
Yep, I also agree that Derek should cease and desist.

This is particularly as I find Derek's underlying malice well out of order.

...

Proving feedback to Ben (Hard is easy) is given in good faith and intended to help him improve.
Derek is fixated on the colloquial use of the phrase 'basic 101' test procedures and misses the point of the concept of improvement and confuses it with constructive versus destructive intent.

There is nothing intrinsically wrong with using a load cell to measure force.
In fact, it is quite a simple and basic '101' concept.
Load a knot and observe what happens...is the knot jam resistant?
No? Okay, at what load threshold does it jam?

The #1047 F8 eye knot can be tied in 4 different ways, presumably Ashley intentionally omitted #1047a, #1047b, and #1047c where he could have illustrated both chirality changes, arrangement of rope segments within the knot core, and different ways in which the F8 can be loaded?

Had he gone down this path, his book would have increased in volume - because he would now be entering a domain where a knot species is defined by its loading profile rather that its geometry.
#1074 Bowline with a bight can be through loaded in a mid-line position - so presumably it needs a separate entry in 'ABoK' as #1074a?

As for actually defining the term jamming - this is something that Ben could have done - since it was the focus of his testing. This is a missed opportunity - and that's not an insult - its simply a statement of fact. I have had conversations with Xarax about the limitations with human hand strength - and the wide variance between individuals abilities in untying knots. But, I personally think the notional concept of threshold jamming state has merit. Increasing the load beyond this threshold state (in an F8 knot) causes further phase changes - until eventually the knot reaches an irreversible jamming state

Another basic 101 test procedure is to identify the test article.
There is huge variance in climbing ropes - and indeed, there is huge variance across all ropes.
Not specifying the test article does make it more difficult for others to try to repeat Ben's results.
I hold a personal view that Derek has missed the fact that climbing ropes come in many different 'shapes and sizes'...all with varying performance characteristics. The same can be said of low stretch ropes (EN1891) - there is huge variance.

Also, holding a drop mass of unknown quantity and releasing it by hand naturally introduces variance from one test drop to the next. Yes - Ben's test involved the use of force. But what magnitude?
Thats not being offensive, thats simply a statement of fact.

...

I think that Derek's fixation with defining basic 101 rules of testing has led him to miss that providing feedback can help someone improve - it doesn't have to interpreted as insulting or destructive. Also, Derek's fixation on what constitutes editing is imaginative and fanciful.
Bolding a word does not alter its dictionary meaning. Sentence structure and underlying intent is not modified by 'bolding'.
I think the real issue is that I am revealing the carefully constructed underlying malice in Derek's narrative - and he dislikes being caught out :)  :)
...

 As for the continued lifespan of this topic thread - I think it is a dead end.

Although, Derek could start an entirely new topic titled:
"How to design a knot test method that is both repeatable and removes/reduces experimental uncertainty"
« Last Edit: September 14, 2021, 10:34:20 PM by agent_smith »