Southern Pacific Company The Southern Pacific (or Espee from the railroad initials) was an American Class I railroad network that existed from 1865 to 1996 and operated largely in the Western United States. The system was operated by various companies under the names ...

's MC-6 class of

steam locomotive A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, Fuel oil, oil or, rarely, Wood fuel, wood) to heat ...

s is made up of two batches: the first consisting of 15 locomotives weighing built in 1912, the second consisting of 5 locomotives weighing built in 1913. All of the locomotives were built by

Baldwin Locomotive Works The Baldwin Locomotive Works (BLW) was an American manufacturer of railway locomotives from 1825 to 1951. Originally located in Philadelphia, Pennsylvania, it moved to nearby Eddystone, Pennsylvania, Eddystone in the early 20th century. The com ...

. This was the last class of 2-8-8-2 locomotives that Southern Pacific (SP) ordered as

cab forward The term cab forward refers to various Rail transport, rail and road vehicle designs that place the driver's compartment substantially farther towards the front than is common practice. Rail locomotives In steam locomotive design, a cab-forwa ...

locomotives. Locomotive number 4043, the newest of the early class of MC-6 locomotives, was displayed at the

Panama–Pacific International Exposition The Panama–Pacific International Exposition was a world's fair held in San Francisco, California, United States, from February 20 to December 4, 1915. Its stated purpose was to celebrate the completion of the Panama Canal, but it was widely s ...

along with SP's first locomotive, '' C. P. Huntington''. All but three of the locomotives in this class were rebuilt as the AC-3 class with "simpled" uniform cylinders of by 1930. The last three were thus rebuilt in 1937. During the rebuild, 4¼-BL Worthington

feedwater heater A feedwater heater is a power plant component used to pre-heat water delivered to a steam generating boiler. Preheating the feedwater reduces the irreversibilities involved in steam generation and therefore improves the thermodynamic efficiency o ...

s were also installed on the fireman's side of the locomotives. After their rebuilds, the locomotives were used through the end of World War II with the last one scrapped on August 20, 1949.

References

* {{SP cab forward locomotives MC-6 2-8-8-2 locomotives Baldwin locomotives Mallet locomotives Steam locomotives of the United States Railway locomotives introduced in 1912 Scrapped locomotives Standard-gauge locomotives of the United States Cab forward steam locomotives