The structure could also be described as an open i.e. torsionless Elbow,
referring to it's two-dimensional likeness to the proper Elbow, ...
/ /
The knot's nipping structure should be dressed in it's signature elbow-like
tressed form for easy identification. This last step is not critical to the function
of the knot, but serves to confirm that it has been tied correctly.
I'm having trouble with this "Elbow" [capitalized!] structure :
should it be familiar to us? --else, any references to cite?
As for "not critical ...", there should be something definite
said here about dressing --not an either/or/anything-goes
indication, as this seems to be. (E.g., one could ask for one
form --for checking correct crossings--,
and then specify that
this more open form be set into something more compact.
And, yes, it might be that the entanglement tolerates open
or compact dressings --which could be helpful if working with
such stiff rope that compactness was not easily achievable
(thinking of some ornery BW II old rope I have beside me!).)
The Tresse Bowline was tied in a variety of materials and natures thereof.*
Informal tests --some involving forces of up to 350 lbs.-- were conducted
and in all cases the knot performed admirably while demonstrating an ability
to maintain a good balance of the most desirable knot attributes. The tests
(which included shaking, whipping, flipping, flopping, and dropping) ...
/ /
With respect to some simple static load testing,
the Tresse Bowline was indicated to be weaker than Bowline #1010.
And among these tests was one (or more) that entailed breaking
the knot, such that your assertion of strength compared with the
(common / #1010) bowline has a basis? --surprising my guess.
What material was used, and how many tests (for strength)?
(And did you set the knot so (overly) snug as SS369 shows?!)
indicated that the Tresse Bowline is:
Stable
Secure
Not prone to jamming
Not prone to ring-loaded failure
Easy to untie after heavy loading
But missing from this set of qualities is the one most important
to rockclimbers (& other life-critical uses) :
slack security(unless "security" is to mean this --but then it should be noted,
as security-under-strain is the usual sense (and has become
more relevant with some modern fibres!)).
Knot efficiency tends to be the least important of desirable knot attributes
due to the high unknotted breaking strength of modern lines.
It's unfortunate that "efficiency" has been introduced into
the knotting literature as a synonym for "strength" : it should
serve more generally, not only indicating how much of tensile
strength is *consumed* in the knot, but how much material
is used, and maybe how much time --as for some applications,
this might be critical.
As for "strength of modern lines", I don't buy this : one hopes
to preserve whatever strength one has, usually --you don't
replace 3/8" double-braid polyester with 3/8" HMPE and take
consolation that the lines have roughly equal
knotted strength;
no, you hope to replace the thicker & much heavier (and stretchier)
line with much lighter & thinner (sometimes thinness is a problem,
though!) but possibly more costly line which suffers no greater
loss of termination (knotting or, as we know, splicing) strength
efficiency.
Of particular interest to me is how the knot would perform in HMPE Spectra/Dyneema.
Any takers?
For starters, there is the doubt that knotting such material
is at all worthwhile in terms of strength --all testing of it
so far has cast doubt as to knots being anywhere reasonably
strong as we would expect, from historical materials.
Of particular interest should be this video of Brion Toss's test
of not-quite-my-recommended
"mirrored bowline" --he omitted
the reflected collar, alas--:
www.youtube.com/watch?v=Fy6Y2Xoo4Ak [ in 5/32" HMPE 12-strand ]
.:. the eye knot holds, but breaks at what Toss guesses
is not-so-high load --the device wasn't calibrated(?!).
It's doubtful that a particular Bowline will ever be discovered
that would achieve "Holy Grail" status, but I would argue that
the Tresse Bowline can come closest to the ideal
"Bowline for all Reasons", more than any other.
Firstly, one could ask why one puts "bowline" into this
quest for a Holy Grail --why not simply leave it open to
whatever meets the presumed requirments. Then, one
can question that any set of requirements can be agreed
upon as constituting Holy Grail! --more likely, it will be
shown that different applications simply don't
needsome such included qualities, but they might not be in
conflict with ones that they do need.
But I'll question how you see this variant as superior to the
mirrored bowline, which to my mind has demonstrably
better security when slack (and is easier to tie in that BW II !)?
Somewhat similar to what the OP shows was discussed
some years ago as a follow-on version to the OP's knots
presented here
http://igkt.net/sm/index.php?topic=1080.0#msg7298&
http://hilarynelson.com/Hobbies/Knots--the "improved" knot, i.e..
I'd tend to give this (as is noted) an additional binding
wrap; there might be some tweaking in the dressing
stage to enhance strength, but that's pointing towards
a dubious quality if indeed such care is needed; it otherwise
seems to have
blood-knot features, and maybe the tight
turn of the SPart doesn't play so important a role in strength
as one might fear --that the tightening coil of wraps around
this will help. (untested, to my awareness)
WARNING! It should go without saying, but nevertheless it cannot be overstated,
--from none to all !!
... that any knot which might be considered for applications where life
is on the line must undergo rigorous testing procedures in a safe, secure,
and controlled environment by experts or professionals in order to prove
it's worthiness for such applications.
"professionals or experts" : I might prefer just the latter,
however they might fit the former.
But can you truly say that this is the case for state-of-the-practice
knots? E.g., we heard not so long ago from a British caver about
the use of the
bowline on a bight with regard to some French testing
that showed it to have a vulnerability to spill, in a special case.
.:. It would behoove some group of experts to build a check list
of testing that could be regarded as rigorous. I think that in most
cases one will find that testing amounts to some form of strength
testing --be it static or dynamic loading--; and that says not much
regarding slack-security, and other qualities; and even regarding
strength, the testing might be less than rigorous. (E.g., the slow-pull
loading of a test device doesn't well model the holding-a-mass loading
one would have, say, in abseiling --where, if the
offset water knot"rolls", it gets a sort of "shock" loading, not a delay while the device
regains tension !)
--dl*
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