Train

Trains are a Gold generating Unit created by Factories. Whenever they visit a station at a Port, or City, they give out gold based on the relationship between the train owner and the station owner.

Trains are generated at a random interval, but averaging 16.5s/train. The average interval is lowered to 9s/train for a level 2 factory and 5.25s/train for a level 4 factory. According to Bob Gold this is formula used : y = (x/1.5x + 15) where y = trains/second.

Currently trains generate 10k for each of your cities they visit(that is for the first 10 or so). Upgrading individual cities that are connected to the factory have no benefit, but adding more individual cities on the line will net more stops per train.