The hitch must hold well ... .
The obvious question is: How
what well? What's the use, here?
A usual situation is a swing--which implies a change in angle of the S.Part.
But the proximity of the trunk to rope suggests NOT such movement
(bumper swinging? ).
But a quick answer to your question is that the Clove hitch of your structure
(that is what those "Two Half Hitches" make) should be replaced with a
Rolling/Magnus Hitch--i.e., given an extra turn, preferably on the S.Part
side of the
structure (downward side, in this case); this hitch component
of the
noose-hitch structure (my term for such things where the main
line is
tied to , not so directly
participating in the knotting)
will be able to be set pretty snug to the limb, and shouldn't move much.
And you could achieve much the same effect by modifying the Timber Hitch
by making a similar wrapping of the struture's main line, to get this
friction
grip that keeps the knotting close to the limb.
And, for a third novel idea, using a short piece of, oh, 2"diameter dowel,
you could bring the line up under/against the limb,
arc it around (clockwise per your images) and tie to the limb with
a Clove Hitch--which binds the mainline to the limb;
then tuck the end through your arc'd loop, insert the dowel
there also, and draw down & tight the main line. (The Clove h.l is
probably the tightest binding you can put on the line to bring it
snug against the limb; the dowel ensures that the load won't
flype the knot. (A 4th idea, springing from criticism of this one
as possibly putting rope-on-rope chafing at the 1st contact,
is to engage the dowel immediately and somehow then seize
it to the limb, but that
exercise is left to the reader (& the writer!) .)
--dl*
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