By definition, if it is imperative to do further tail maneuvering to lock-down
a knot, then it isn't secure!
But this statement makes it seem that security is some
kind of black-&-white, yes/no condition, which it is not,
versus a variable state influenced by various factors,
such as loading, material, "jostling/rubbing" and user
attention to setting. (E.g., I recall reading on a forum
one rockclimber gal's assertion that sometimes her
strangle knot back-up has loosened --if not come
fully untied. (!!))
And I distinctly recall the
EBDB which I designed expressly
to be slack-secure** in typical kernmantle ropes to mock my
good efforts in some small, laid, hard-to-hand (though
flexible, & I'd say moderately soft-laid) polypropylene
cord by holding only for a minute or so --on my
2nd and
forceful setting-- and then all at once just loosening,
turns-around-turns sympathetically relaxing !!! WTH?! !

**Ah, and we're talking about this sort of security,
but in the HMPE universe we face challenges of
security-when-loaded (vs. slippage)!
One might have some term/expression to distinguish
between knots that are secure but not really *tight*
--not snugged up on setting into a jammed knot--
and those that are to be set tight. E.g., the whole
point of the
mirrored bowline --and here I'll remark
that the similar structure with the
clove h. bwl./water bwlmight be more visually appealing, and as effective--
is that the knot while obviously NOT set snug-tight
is yet resistant to
further loosening, by virtue of all
the parts therein bearing against one another sufficiently
frictively enough to stay tied.
((And I wonder :: so far as I'm attentively aware (sigh),
the UIAA drop test specifications only require a
fig.8 eyeknottermination of a test specimen, yes?
[edit : NO, they now at least require clamping, not knotting.]
(and where's the spec.
for THAT knot, in exact form, and for length of its eye?).
What do you think would be the effect of having a drop-test
series run on
fig.8-tied line vs
mirrored bwl.-tied line?
That maybe the latter would never cinch tight, and thus
repeatedly offer
some knot-compression to mitigate
peak impact force, which in turn might lead to a greater
number of sustained falls?! --or could there be the odd
coincidence that while indeed the above difference in
forces obtained, that all that load mitigation, which
comes through some kind of rope(on rope) movement,
accumulated such abrasion & heat damage/weakening
that the same # of drops were held,
though with the one specimen never obtaining so high
a peak impact force as the other (and at least in that
case, not so much stressing other components). !?!

))
--dl*
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