I was inspired by the other 55 ton coal car on thingverse but I wanted to design somersetting in the way that it could best utilize the best printing orientation for detail. So i fired up fusion 360 and went to work! This model requires assembly but as the pictures show the outcome is worth it.
The model was designed around micro trains trucks and the base has extra clearance provided for them so they don't have any issues on the track. I weighted mine down with led shot to 10grams each then filled with black ballast for a coal load. With that weight it can go full speed around 9 3/4" radius at full speed without toppling over.
Instructions is to glue each side piece to the base with super glue, thin is best if you can control the flow but if not use medium because thin will fill the gaps in between the steps, as strait as possible followed by the ends and finally the inner baffle.
print at best settings possible.