Thanks for the information.
That's correct, an overhand knot is used to create a loop, the loops are then joined with larkshead knots to create the 3-leg bridle.
"Larkshead" & "girth" get used here where they don't really belong, and in rockclimbing
also. It might be that the knot is somewhat tied in a Girth-hitch fashion,
but the effective, set shape is that of a Square knot (in rope; rockclimbers use it
for joining slings of tape, and there the knot is asymmetric in actual material
geometry (it is hard to work out a symmetric form)). I.e., the closing part
between the two loop legs making this hitch doesn't bind around them, but
around the opposing legs & vice versa. Better to not have one knotname denote
such different structures!
All lengths are predefined on a bridle rig, and then the positions where the bridle should be tied to the kite are marked with a permanent marker. So no adjustments are necessary, hence it doesn't matter whether the knot can be untied or not, as this is the final bridle setup,
... and one doesn't disconnect the long line from the kite, for storage or
replacement (or maybe we are not seeing even so far as the long line?)?
Material used indeed is HMPE or Dyneema/Spectra with a 150lbs breaking strength.
It is almost surprising to hear the it can be so weak! But, yes, at 0.5mm!!!
Now there comes a tougher tying issue, working with such a small dimension.
The line is very smooth and thin (0.5mm), and will work itself free out of every low friction knot.
In the knots that you show later (red & blue cord), I take it that the blue cord
represents a third of its part, i.e. one of the three eyes. But we are looking to
replace that structure with perhaps a single knot.
The A-knot is something I thought up myself, but that comes lose under strain, but looks nice, is small, and has a very smooth finish (so it will not cause for other bridle lines to get caught behind the knot).
This is a (dble) Strangle Knot/hitch, aka Nail Knot (given how you've effected its
tying) by anglers. I'm a little surprised that it loosens; one could give it a few more
wraps. But there are similar structures that might work better.
Knot-B is what I gave as an example of a single knot, although you refer to a loop
catching things, and in my conception there is no loop, as the ends from the 3
bridle legs are untied. So, one would have three ends vice the loop, on that side,
and one end (and 3 legs) on the other. But it is large around.
Knot-C I think would be stronger were the single line brought far into the
tying and its wraps around itself going back.
Do you know the Blood Knot? (an angler's knot) Each end passes the other,
and then is wrapped back around the passed lines to be tucked down between
them in the center. Although one source found this old knot to be weak in some
of the "gel-spun" HMPE fishing lines, I think it might not be so in the kite cord
and given the amount of material in play (the heavily loaded single line wrapping
around 3 opposed lines, not merely one; the 3 in turn having only need of
about 1/3 strength in opposition, but also wrapping around several parts (they
wrap around themselves)).
But precise measurement might be more of a challenge. Security should be fine.
Aerodynamic aspects should be good, with a relatively thin, single knot, and
no doubled lines beyond (i.e., not the twin legs of loopknots leading to the statellite
Overhands).
At the cord-to-tape (kite) end, one can try a similar sort of structure, a sort of
adaptation/extension of a Lapp Bend. Especially if one can perhaps fold the tape
in order to provide a both firmer & trimmer U-shape for tying to.
Bring the cord near-parallel diagonally across the tape U; wrap cord back around
all parts once, twice, then around just the leading U side and itself going thus
down through the bight/U and around again & down. The U's tip will nip the
end of the cord tucked down through it (twice (or more)); the wraps will bind
the cord at the other end and prevent loosening; and the wraps should also
help reduce the aero-profile of the tape some!?
AND the tying of this knot can be done to effect some length-adjustment of
each leg (assuming that the bridle joint to long line/connector is done prior).
This would be like you Knot-B, but with the red cord 1) not going through the
tape's U, and then instead of being tucked out through its own wraps, it would
be down & around the red & near blue parts, twice. (For cord-to-cord, it might
be better to begin through the U as done with your Strangle hitch, and so is an
option for that end of things, though it means that you still have the 3 Overhand
loopknots for each bridle leg.)
*knudeNoggin*