I have been wondering about this myself. I lived near Bryson City, N.C., the headquarters of the Great Smoky Mountains Railroad, and that is one tough piece of railroad. Sharp curves and grades over 4.5 percent. When the line was run by the Southern Railway, every train ran with at least three GP-30 engines. One engine was good for only eight cars on the steepest part of the line. In steam days, they used fairly large 2-8-0 engines, and the rule of thumb was one engine for every five cars! I have no idea how a little 4-6-0 will cope with that line.
