The EDK simply does not meet certain fundamental requirements: It slips way too easily.
That this controlled slippage is known about and accepted as normal by some is not a good
reason to place undeserved virtue on the EDK. The argument goes that the EDK has been
used for quite some time and has not been attributed to deaths (or a bunch of accidents),
hence it is good. This is a subjective argument that is fallacious from my viewpoint.
Spitting into the wind is one thing,
mischaracterizing arguments is worse.
There is nothing "subjective" about pointing to the
quite objective point that the offset water knot has been
used for ages --in the very materials of issue-- without
failure. And it's certainly worth pointing that out.
--dl*
====
I am not mis-characterizing anything.
Okay, you don't deny the facts of non-failure in
long-standing practice, but challenge that that
ipso facto is a good basis.
IMO, it certainly IS. Consider it "trialling" and then
ask if anything else has been so thoroughly tested?!
An objective measure of a knot is 'does it slip' at a certain load or % of mbs or other well defined criteria.
Except that we've seen that even defining "slip"
is a matter of debate --is it really in any way doing
some dangerous "slipping" if it's just adjusting to
forces from a low-force setting?! When a knot is
taken to break point, one might conclude that
slippage wasn't a problem (YMMV).
Trying to convince anyone that the EDK is objectively good because it has been "used for ages" is plainly wrong. The "without failure" part is without qualification. How is the knot tied? Is it being embellished by a back-up knot? The EDK slips in the materials that it is used in at working loads, that is "a failure" to me. We have seen trials showing us exactly this.
?! On the contrary, while we might not know in
given detail even on most uses, we can know by
testimony and example how folks tie and use the
knot, and have otherwise to think how thousands
& repeated thousands of application-specific uses
have not brought anyone --even!-- to grief. Again,
that is a vast amount of "practical testing" to deny!
If you want to believe the "used for ages" argument I suppose a "granny knot" would be an even better knot to try mountaineering with, since that does not fail in everyday life (we would hear about all the accidents) and has been used by millions a lot longer than the EDK. Very few climbing accidents/deaths from it, so it must be good, right? I make a deliberately stupid argument, however not much more so than the EDK one I keep hearing in my opinion.
This defies reason : the
granny knot has NOT been used
AT ALL in the materials or application of rockclimbing, point
blank obvious, and in stark contrast to the
offset water knotwhich has long-standing usage.
(Now, as an aside, the "longstanding usage ..." reasoning must
be chary of all assumptions/contexts :: bring a new material
such as HMPE into the situation, and you might have other
than the longstanding happy behavior! One had a sort of this
realization in seeing the ca. 2001 HSE (UK) study of using
the
clove hitch for termination, where of their several tested
ropes, only the dynamic one held (IIRC), all of the tested
low-elongation ropes slipping at widely different loads ::
one could see a rockclimber who had confidence from
longstanding use of the knot in climbing ropes finding
unpleasant behavior in more inelastic stuff.
But you don't have any experience of
granny knots climbing.)
I have said this a number of times: Find a better knot. Anyone who wants to help, great. If not, I will find one on my own.
And so you have --and have already done some testing of just
such a Found-Better Knot--, viz., the
offset 9-Oh, which takes
the design goal of being offset (for smooth traverse of rough
services including edges), efficient tying and consumption
of material ("small footprint" to cite a term), and suitability
or joining dissimilar (within application bounds (6mm + 11mm?))
ropes, and began with the offsetting of the S.Parts and then the
sure nipping of the choke point with a
full turn by one
of the two ropes --spec'd the
thinner / more flexible one,
and thus the accommodation of dissimilar ropes.
And it works, as you've shown.
Even *hastening* the tying above, to yield the
offset 8-Oh,one gets a half-turn less choking but now has the new
(vs.
EDK) aspect of tails going out of the nipping area
in opposite directions, so that there is an end on either side,
not both on one and connected parts on the opposite side.
That looks promising, but somehow it has seemed to me
that its resistance to capsizing looks less good, and with
the
9-Oh looking good and just a half-turn away,
I would favor that.
BUT, unlike the
"EDK-backed EDK", both require that one
orient the thick-2-thin tying in just such a way, for ideal
and most sure results, at least --perhaps in reasonable
counter orientations per the application (e.g., 6mm tied
with 10mm), they still work, albeit with less of a margin
of surety!?
Ditto for simply tying off the
offset water knot's choking-part
tail (which again should be the thinner/flexible rope if uneven) :
it works well in the specified orientation, but does require
that one note and achieve such orientation,
and should offer less security if botched in this regard.
IMO, that clumsy
EDK-backed EDK might suffer not only
botched & varied per-knot orientation (e.g., thickier rope
choking) but also spaced back-up (which could enable
a "roll" of the primary knot before hitting the stopper)!?
--dl*
====