CMC Podcast on BOWLINES

[agent_smith]

Hello my fellow knot geeks!

Here is an interesting podcast about 'Bowlines'.
Title of podcast: Are Bowlines safe enough for rescue?
Link: https://www.youtube.com/watch?v=NUlm3BLKmoo

Commentary:
1. My name is thrown about - which is both 'good' and 'bad'.
2. I think the title of the podcast is flawed and so is the underlying premise.
3. Kelly Byrne refers to his technical ITRS presented paper on 'Boutique Bowlines' - Link to that paper is on the podcast webpage. This paper largely resorts to the default "pull-it-till-it-breaks" mindset, with not much beyond that underlying premise. For example, there was a missed opportunity to test the effect of having 3 rope diameters inside the nipping loop. Also, one or two knot break tests had higher MBS yield than an unknotted 'control' rope.
4. The commentators frequently simply refer to 'Bowlines' as if it was only one type of structure - this reveals fundamentally flawed thinking (there are many different type of 'Bowlines' - and in fact there is a subclass of 'Bowlines' which are inherently secure). For example, the podcast title could be changed to: Are inherently secure Bowlines safe enough for rescue? Would this title change affect the mindset of the commentators?
  Indeed, when the commentators use the term 'Bowline' - I had the distinct impression that each of them conceptualized a different structure. Some probably can only conceptualize the Simple (#1010) Bowline (which is clearly and obviously not stable and secure under slack shaking and cyclic loading conditions).
5. The commentators frequently refer to "what if a person screws up tying the knot" - that is - there is a risk that a person could miss tie a 'Bowline' and this is implied as a reason why 'Bowlines' may be 'unsafe'. In my personal view, this argument is frequently cited by many commentators around the world - and it flawed thinking.
6. The commentators have a clear bias toward thinking that MBS yield (ie strength) is the most important aspect of a knot (and they cite this as 'efficiency'). I have a fundamental disagreement with this concept. Knot efficient should NOT be conceptualized in terms of pure MBS yield.
7. The commentators appeared to struggle with the notional concepts of 'slack shaking', 'cyclic loading', and stability and security. In particular, they commented that they had no clear definition of how to perform a standardized test of a knots resistance to cyclic loading and slack shaking. In a strict scientific sense - it is true to state that there is no standardized test regime for measuring a knots resistance to these types of loading profiles. A 'standardized test' means a test procedure that can be repeated by other testers (consistency).

I could go on and on but I'll stop here...

[KC]

As far as safety, i think a lot depends on type of rope/device Bowline is tied in.
DBY is my preferred clean, open ending eye;
but some very stiff ropes can feel rope not seating as adequately to the tight curves around self.
3x180 arc versions (Round Turn, Water etc. Bowlines) mitigate some stiff ropes problems not all.
It is my favorite, but not in a very stiff, polyester, double braid etc.;
listening to rope as dances in fingers towards form, Bowline can tell you this is not job for it as not seating to the tight bight as well in these lines.
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i also think DBY is more symmetrical to eye check than standard Bowline.
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i think beyond just the macho strength  part of numbers watch, a reaching that does drive us forward;
using a more efficient knot/strategy; one that can hold more weight in same materials and design,
can add more life and confidence to rope; just as un-kinked chain would over kinked.
More efficient knot has more 'max headroom'/strength, because carries same load w/less inner pressures, more efficiently.
Still breaks at same internal pressures imposed by the external loadings,
under continuous loadings, fractures ceilings less when more efficient to same loads; leaving more max headroom.
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PoD is more loose, honest front porch sharing than over practiced, slick, clinical studio presentation.
Would perhaps expect CMC production more clinically defining as a business and an industry leader, tester; immersed in rope always.
Perhaps not such a peak behind the curtain would demand more respect, but less open.
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[img=https://itrsonline.org/wordpress/wp-content/uploads/2019/10/Byrne_Boutique-Bowlines.2019.pdf]http://pdf: itrsonline.org/wordpress/..../Byrne_Boutique-Bowlines.2019.pdf[/img] not working in 3 browsers for me.
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i think each knot can be defined by how shaped, but that generally assumes a specific loading profile.
Just as when prying with a screwdriver, can describe screwdriver as a screwdriver or lever.
Just as Constrictor/Bag/Ground Line all can be formed 'cold' w/o force and recognized, but forged into actual 'hot' loaded w/forces  usage strength/efficiency etc. vary then by how force ported thru the same cold drawn form.