2008 went where 2009 is sure to go.
I started designing sprinklers in 1976, all schedule 40 pipe having threaded fittings with 90% of the systems designed per pipe schedule, and sometimes I feel old looking at my first systems thinking "man, this pipe is old...."
I am going to hit the big six zero next week. Wife is already planning the party and I wish she wouldn't.
The NFPA book I used, I think it was 1974, was a little "red book" of about 120 pages.
I did a number of gridded dry systems in the 80's and the Ohio Fire Code at the time required all dry systems to get water in 60 seconds and doing this I learned some "tricks".
Keep the system small. No more then 200 to 250 gallons.
Use grids only on systems with high water pressures. You were asking for trouble where the water supply was 50/40 @ 800 gpm.
Accelerators on everything.
Connect the near and far mains with a cross main keeping all the mains at a lower elevation than branch lines. The idea was to fill the mains while trapping the air in the overhead branch lines.
Some people got crazy and had side feed grids with 600 gallons which is where you had problems.
Merry Christmas and happy new year to all!