Union Pacific No. 6051 is a Consolidation (2-8-0) type locomotive was built in 1907 by the Baldwin Locomotive Works for the San Pedro, Los Angeles & Salt Lake Railroad as #642. In 1916, it became Los Angeles & Salt Lake #3642 and then #6051 in 1921 when the Union Pacific took over the LA&SL. Leased to the UP in 1936 and renumbered #6021, it was donated to the City of Riverside, CA, in 1954.
As built, #6051 weighed 187,000 lbs. The Vanderbilt tender weighs 135,050 lbs. light and has a capacity of 7,000 gallons of water and 14 tons of coal. The engine has 57" drivers, Stephenson valve gear and 22" x 30" cylinders. With a 49.5 sq ft grate, 177 sq ft firebox and total heating surface of 3,403 sq ft, it operated at a boiler pressure of 200 psi delivering 43,305 lbs. tractive effort. From 1936, superheaters were fitted to all in-service C-2s when one hundred and seventy-two boiler tubes were replaced by thirty-two flues. The engine weight rose by about 3,000 lbs., but little else changed.
