Class Sound DCC and Smoke Paragon4 Union Pacific #829 (2-Tone Gray, yellow)Details: The Northern type locomotives on the Union Pacific were built by Alco Schenectady Works in 3 classes between August 1937 and December 1944. The first class, designated FEF 1, for Four Eight Four, comprised numbers 800 819. Fitted with 77 inch drivers and a 300 pound boiler pressure, UP was impressed by their performance and took delivery of 15 additional 4 8 4 locomotives in Aug Oct 1939, numbers 820 834. These locomotives were equipped with