HOW TO CONFIGURE STATIONS IN THE STACKER The easiest way is to just use a blueprint, but if you want to manually do it, add a new line, copy the station & signals from the other lines, and add a red wire to the station. Done!
HOW TO CONFIGURE TRAINS After you've built your trains (1-2-1), configure this:
Outpost -> Full load Depot -> (item) > 0 Unloading -> Empty cargo LIQUIDS
Do everything the same, but for the unloading, select Unloading Liquid station and use these conditions:
CARGO -> empty barrel = 400 AND CARGO -> (Liquid barrel) = 0
Original Design was by Xperiment69 ( K8SWv7CAGAGynH3vG ) all credit goes to him ♥