This is the PRR S-1, a 6-4-4-6 non-articulated locomotive on a rigid frame.
The engine alone weighed half a million pounds, and the tender over 400,000. It was designed by Raymond Loewy, the most famous industrial designer of the 20th century.
(That's him standing on the S-1)
Loewy also designed the 1953 Studebaker Starliner Coupe, teaching America what exterior automotive styling was all about.
He also designed an item whose classic shape is known around the world...the COKE BOTTLE!
Bad Order Hal