Hi, Beau. Agent_Smith has been silent & inactive for some time,
and I suppose that is answer enough to your question insofar as
his testing is concerned.
For may part, I have not yet sought testing of this particular focus,
but did include a sort of *
Fig.8/false bowline* among 5 eyeknots I had
tested in 8mm(5/16") 12-strand urethane-coated HMPE (Dyneema
SK-75); it did not slip, but was unremarkable re strength (somewhere
in the range of results from 33-42% (37%) for the five, each test
specimen having the same knot on each end (so, one survivor).
As for the
bowline with Yosemite finish (which exact finish one can
see differing between various references, as to which side of the
S.Part it lies --tighter vs. less tight final turn), I concur in your
questioning of how that could influence strength --though it is
an assertion made by Craig Connally, author of
The Mountaineering
Handbook , there and in posts to RC.com (
www.rockclimbing.com).
The same goes for the double(-knotted) bowline. Is it actually proven to be stronger (and why?) or is it just harder to capsize?
By which name I assume you mean what is also named "Round turn" &
"Double" bowline --an extra (round) turn for the central nipping part,
same end-forms-bight finish. Tests have shown this to be stronger, I
believe, and about the same strength --so, YMMV. What you almost
NEVER see in test reports is a clear indication of the exact geometry
of the tested item : no, you have a name --e.g.,
"Fig.8 on a bight"--
and that can denote all sorts of dressings of some general knot.
Capsizing I don't think is much an issue with
bowlines, though for
some reason, many in the mooring hawsers of trawlers within my
periodic inspection seem to have them(!?). What the extra turn
in the
Dbl.Bwl. does is provide a better grip (for security) and
the extra turn helps impede loosening, in that any slack feeding
into the knot had 2 vs. 1 loop to loosen --the slack is *amortized*
over twice the looping --so, some small benefit.
which bowline variant or which life support knot is the best
Define "best" --there's the rub. Or, for that matter, how much better
one knot should be over others in order to gain such acclaim? Often
there are trade-offs between
- ease of understanding vs.
- tying vs. "strength" vs.
- security (when slack, most often) vs.
- ease of untying vs.
- material consumption vs.
- ease of inspecting vs.
- being in common knowledge/use
!!!
E.g., the
Fig.8 eyeknot is often promoted over the bowline because
--in part-- it is supposedly easier to inspect (for correct tying)
(even though precise geometries of this common knot are seldom
presented for instruction --anything is correct enuff!), but MUCH
of the problem with the
bowline, IMO, is the way it is presented,
showing it from a side in which the crossing of the central
nipping loop is beneath the easily understood/perceived paths
of the legs of the end bight! --geeesh, just flip that knot around!
But presentation after presentation show the bowline from the
wrong perspective, and ... people have difficulty understanding
the knot. Then, with the result of a sort of corollary, non-practice
makes imperfect --self-fulfilling prophesy. (Concerns about Bwl.
security are valid, but many solutions are available; but then it's
the "many" aspect that frustrates learning and common understanding.)
As for
... claimed to be rather weak [bowline, i.e.]
no, the
bowline is not all so weak, maybe esp. in the cordage used
(perhaps esp. in dynamic rope). But the figures do have a range,
enough again to make you want to know the unreported details
of knot geometry and so on.
--dl*
====
