Union Pacific's massive 4-8-8-4 "Big Boys" were the road's signature freight power, during the war years. When problems with smoke drifting back into the cab and obscuring the crew's visibility occurred, large sheet metal smoke deflectors (sometimes called "elephant ears") were added to #4019 as a test during the winter of 1945. By January of 1946, tests showed that an improved blower was a better option for smoke control and the deflectors were removed.
 
Based on the prototype as it appeared during this time, the model is superbly detailed with working lights, crew figures, metal grab irons, Boxpok drivers and much more. The engine is also equipped with a dual-mode DCC sound and control decoder to enhance operations. The powerful motor drives all eight main axles, and traction tires provide additional pulling power. An articulated frame allows operation on tighter curves.