The reciprocating mass of a good size steam locomotive might exceed 2000 #'s. Kind of like an entire volkswagen beetle bouncing up and down a huge stroke at 80 mph. That analogy was given to me from the crew of the restored Daylight 4-8-4 that was operating out of Portland.
I used to share office space with a British steam enthusiast, and as they are so apt to do, he took pleasure in pointing out what he thought were deficiencies in American steam design (which ended long before British so was deprived of several decades of mechanical and metallurgical development). But it always stopped him cold when asked to compare tractive force. What I knew but did not admit, was that Britain BY DESIGN didn't need a lot of tractive force in their locomotives, relatively flat country with shorter trains.
Similar arguments could be drawn between our 'primitive' but hugely successful FE engines, compared to something more "properly" (but daintily) designed.
It is a fine time for all steam enthusiasts that UP is restoring one of the 4000 series locos, considered by many to be the best of all. For train enthusiasts, that is not unlike if Ford decided to come out with a new model FE in pickup trucks.
