I pretty much concur in Roo's observations.
In such systems as this, there are numerous solutions, any one of which
can be fine. In this case, you might value having an un-cut length of
rope for something that you see as only semi-permanent, able
to be taken down (and re-set-up).
Scott remarks at the dubious reputation of this (oft'-called) "Home
Depot" rope -- is it multi-filament polypropylene? (I have some
stuff like this, found here or there.) But, then, you have EIGHT (-8-)
lines of support, so each needs only hold 125# for that half-ton load.
-- and you don't see actual loading getting to perhaps even a half
of this. Safe Working Load for the rope is ... ?
The long reach parallel to the bar, along the ceiling, puts much
more material in the supports that feed that, and so those will
have more stretch and carry less load than the partner lines
whose reach is the short, perpendicular-to-bar direction.
One could eliminate all but one long reach by starting at one
point (as you do), going down to the bar, up to opposite
side and make a twin-eye knot (to connect to both bolts),
return to the bar, and up to the bolt beside the starting point,
tied off w/hitch, then reach to other end and do this structure
in reverse. -- or all knots could be hitches (some tied in reverse
given working with the single rope). This system could have
completely independent hitches to the bar (or not), giving
full redundancy if any line were cut. (But what's the chance
of such failure?) If your system has a cut, I think it still holds,
certainly for a while.
--dl*
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