Last night, I pulled the trigger, and finally ordered the new control system for the Onondaga Cutoff: a North Coast Engineering (NCE) PowerPro 5-amp radio-control system, with an additional 5-amp booster unit, and the associated hardware. I also ordered 6 breakers designed for this system, one for each of my power districts.
Main Unit: Visible Main Line
Short Line (not yet installed)
Booster Unit: Onondaga Yards/Engine Facility
Staging and hidden mainlines
This arrangement should keep my current draw below the 5-amp maximum, even with up to 4 or 5 units pulling long trains. Both mainline tracks are wired to the same bus. A basic 'blue box' Athearn unit that is in good shape draws about 0.6 to 0.7 amps at full throttle, and most other motors (Atlas, Kato, newer Athearn) are lower, so I can run about 6-8 units at full throttle at once on any power district - even with two big trains on the main line, I should have some spare capacity.
Spending hundreds on a one-shot deal with this hobby is unsettling, but Kristen supports it and at the least this should be the last time I do this for quite a while. My first task will be to install a decoder in a few engines, then make the big switch and hook up the new control system - and a new era will begin!