Like Larry, I've been watching this one also. Those Big Boys are amazing feats of engineering! Mechanical masterpieces! I've ridden about a dozen steam trains over the years, but that one would be the ultimate.
Heo, I remember seeing an older video of a Big Boy running flat out on the plains of the west; there was a conveyor belt that ran the coal into the burn chamber. I was amazed at how fast the belt was running, and remember thinking that their coal supply wouldn't last long at that rate, but I think some of them that ran high speeds like that actually used 2 coal cars.