The Dinosaur Train

I find it awkward that even though the Dinosaur train runs on steam, the fire needed to heat up the water  in the boiler is usually fed coal.  And how is it possible for the train to run with dino passengers weighing several tons, let alone extremely large in size? You figure that the train would have to be much, much bigger and able to support all that extra weight.  I guess it was just the way the train was made and it can handle it all. But I figure that Mr. Troodon has it all worked out somehow.