It is narrow gauge!
This Steam Rail Car is from a dream I had in which it was one of the trains in a amusement park called Mine-Valley. It originally was a passenger baggage mail combined but the amusement park added the open air windows in blue and removed the partitions. the coal and water was stored up under the car making this little engine a well tank. The pan holding the coal slid out to be refilled and the water tank had a place to put a large diameter water hose.
The Steam Rail Car can pull up to three coaches.