Question: did the original F40PH's for RTA/Metra and other commuter operations have separate generator units for electric power to the train, instead of constant-speed prime movers like the Amtrak versions? It was annoying how the Amtrak units would sit around "idling" at full engine speed. I guess it was a cheap way to provide trainline power off the prime mover, made obsolete by better newer technology.
Around 1979 I remember an EMD factory engineer telling me EMD was thinking about developing a two-speed gearbox or some method to allow train power to be developed with the F40PH engine closer to regular idle speed, when the trains were stopped for extended times.
Maybe HW can clarify, I recall being told the engines for F40PH units had finer mesh gears for the cam and turbo gear trains, to better allow prolonged high-RPM low-load operation. Does that sound right?
