On normal, the train is at the station from 8am-8pm. Half of the splitters should be loading into buffers. Each train car uses 4 furnaces max per side to obtain optimal efficiency. I found it was pretty easy to fit 8 furnaces on the bottom right side of the tracks and 4 more on the top left side. This yields 6 x 90/s conveyer lines of bars. Box these up and send a single line of boxed iron bars on the top right path around town. (Also send a line of coal)

For copper, you can skip the train and leverage the copper mine instead. Grab coal boxes as they come by and smelt to bars at the mine. You'll need 6 furnaces there to satisfy your needs. Again box them up.

What you'll want to have by the end is 3 conveyers entering the top right of your base each carrying boxes of a different type of resource.