At 05/11/2013 11:02 PM (), you wrote:
Who said they had to be identical cars. If they are hauling coal or potash or some other cargo that is going to go through a dumper then the cars have to be similar (not necessarily identical) so they will go through the dumper. But not all unit trains go through dumpers and there is nothing I know of that says they have to. They can be bottom dump or whatever. All that matters is the cargo is usually the same and the travels as one train (unit is defined as one) from point A to point B. If you meet that definition you have a "unit" train.
It can be automobiles, nothing says it can't be. We look upon these as long distance trains, but there are lots of train that go very short distance that meet the definition of a unit train - auto parts, containers, etc.
DEC
