Originally Posted by TeeDee
Also I wanted a method that would allow for longer spans than you seem to admit. 20' spans are not uncommon for me. At 17' to 20', the tie off point height can get too high if you limit yourself to 30 degree sag angle.
I look at it that you have solved a particular case of the problem, the 30 degree sag angle. I needed the more general case of varying sag angle and tie off point height.
You always have limits. Mine are 12 feet for minimum span because of the tarp and 18 feet for maximum span because, as you point out, that is the height limit that I can reach for the 30 degree sag without a structural ridgeline. I also have limits on tree diameter. To borrow a line from a Clint Eastwood movie, "A man has to know his limitations".
What maximum span and tree diameter do you pack for? (You probably realize that what I am getting at is having suspension line, tree huggers, whatever, for unnecessarily long spans or for the largest diameter trees in the forest go against the pack light philosophy where you more carefully consider the tradeoffs and what your options are... not that there is anything wrong with doing otherwise.)