Southern Pacific Railroad The Southern Pacific (or Espee from the railroad initials- SP) 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 ...

's MC-2 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, oil or, rarely, wood) to heat water in the locomot ...

s was the first class to be ordered by and built for Southern Pacific (SP) as

cab forward The term cab forward refers to various 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 forward design will ...

locomotives. They were built in 1909 following the design of SP's MC-1 class built earlier that year. The success of this locomotive model led to the design and introduction of the AC class of

4-8-8-2 Under the Whyte notation for the classification of steam locomotives, a 4-8-8-2 is a locomotive with four leading wheels, two sets of eight driving wheels, and a two-wheel trailing truck. Other equivalent classifications are: UIC classification ...

cab forward locomotives in the 1930s and 1940s. In order to get the fuel oil from the tender to the opposite end of the locomotive where the

firebox Firebox may refer to: *Firebox (steam engine), the area where the fuel is burned in a steam engine *Firebox (architecture), the part of a fireplace where fuel is combusted *Firebox Records, a Finnish 8101705801record label * Firebox.com, an electro ...

sat, SP had to pressurize the oil in the tender. of air pressure was sufficient to get the oil to the fire. The two MC-1 locomotives built in May 1909 were rebuilt in 1923 as MC-2 class with uniform cylinders measuring

diameter In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. It can also be defined as the longest chord of the circle. Both definitions are also valid for ...

stroke A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functionin ...

; these rebuilt locomotives weighed , like the as-built MC-2 class, but with on the drivers. Most of the rest of the MC-2 class were "simpled" to the same size cylinders by 1931. Except for numbers 4011 and 4013 which were both scrapped by 1936, all of the MC-2 and the two former MC-1 locomotives were rebuilt again into class AC-1 with a higher boiler pressure, but a lower overall

tractive effort As used in mechanical engineering, the term tractive force can either refer to the total traction a vehicle exerts on a surface, or the amount of the total traction that is parallel to the direction of motion. In railway engineering, the term tr ...

. The MC-2 rebuilds included installation of a new 4-BL Worthington feedwater heater as well. SP used these locomotives until after

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

, retiring and then scrapping them in 1947 and 1948. The last locomotive of this class was scrapped on April 12, 1949, at SP's Sacramento shops.

References

* * {{SP cab forward locomotives MC-2 2-8-8-2 locomotives Baldwin locomotives Mallet locomotives Steam locomotives of the United States Railway locomotives introduced in 1909 Scrapped locomotives Standard gauge locomotives of the United States