Robert K posted:How does WMSR know that the 1309 will be able to handle the line to Frostburg? The curves, etc.? It never ran or was tested on that line before.
The C&O operated many of the H-4, H-5, and H-6 class compound 2-6-6-2 locomotives on far worse curves & grades (even double-headed) than what the WMSR has. Again, you might want to do some research into the C&O coal branch lines and how they used their 2-6-6-2 steam locomotives.