As others have said, power plants even in the modern era vary in size and load requirements.
I decided awhile back to apply a ratio of 1:4 when scaling down my coal trains lengths and shipments between loadouts and power plants. That's one prototype car to four N scale cars. Therefore, my standard unit trains are 24 cars (96 cars) long. This was fairly typical in the late-80s/early 90s for unit trains to Duke Power in the Carolinas, for example.
I have a smaller power plant that takes 10 cars (40 cars) at a time. I use this also to determine shipments from large and small loadouts on the railroad. It has worked rather well and seems to keep things in proportion.
Marcus
Marcus,
Do you have a track plan and/or any photos of your plant. I looked at your website but didn't see anything there, don't know if I missed it though.
I agree with your thoughts on the 1:4 ratio, that was about what I was thinking, as a 24 car train looks long in n-scale on our typically too short mainlines!
Mike
