Many decades ago, I recall riding on the Fort Belvoir Railroad (now gone) locomotive, and the engineer was explaining the various notches in terms of changing connection to the traction motors, putting their components into various combinations of series and parallel.
Which leads me to ask, when diesels are not idling, do they run at (or near) a specified RPM with a governor controlling feed of the fuel to hold it at that RPM under varying electrical load?
