Southern Pacific class MC-2
Encyclopedia
Southern Pacific Railroad
's MC-2 class of steam locomotive
s was the first class to be ordered by and built for Southern Pacific (SP) as cab forward
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
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 sat, SP had to pressurize the oil in the tender. Five pounds-force per square inch (35 kPa
) 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 22 in diameter × 30 in stroke; these rebuilt locomotives weighed 437,000 lb, like the as-built MC-2 class, but with 393,700 lb 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
. The MC-2 rebuilds included installation of a new 4¼-BL Worthington feedwater heater
as well.
SP used these locomotives until after World War II
, 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.
Southern Pacific Railroad
The Southern Pacific Transportation Company , earlier Southern Pacific Railroad and Southern Pacific Company, and usually simply called the Southern Pacific or Espee, was an American railroad....
's MC-2 class of steam locomotive
Steam locomotive
A steam locomotive is a railway locomotive that produces its power through a steam engine. These locomotives are fueled by burning some combustible material, usually coal, wood or oil, to produce steam in a boiler, which drives the steam engine...
s was the first class to be ordered by and built for Southern Pacific (SP) as cab forward
Cab forward
The term cab forward refers to various rail and road vehicle designs which place the driver's compartment substantially farther towards the front than is common practice.- Rail locomotives :...
locomotives. They were built in 1909 following the design of SP's MC-1
Southern Pacific class MC-1
Southern Pacific Railroad's MC-1 class of steam locomotive consisted of two locomotives built by Baldwin Locomotive Works in April 1909. They are the first two locomotives converted by Southern Pacific to run as cab forward locomotives....
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
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:...
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 sat, SP had to pressurize the oil in the tender. Five pounds-force per square inch (35 kPa
KPA
KPA may refer to:* Kenya Ports Authority* Kiln phosphoric acid, a dry process to produce phosphoric acid at high temperature in a kiln* Kilopascal , a unit of pressure* Known-plaintext attack, a method of cryptanalysis* Korean People's Army...
) 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 22 in diameter × 30 in stroke; these rebuilt locomotives weighed 437,000 lb, like the as-built MC-2 class, but with 393,700 lb 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
Southern Pacific class AC-1
Southern Pacific Railroad's AC-1 class of cab forward steam locomotives consisted of locomotives rebuilt from MC-1 and MC-2 class locomotives that were originally built by Baldwin Locomotive Works in 1909. The MC-2 class was the first class of locomotives built and delivered to SP as cab forward...
with a higher boiler pressure, but a lower overall tractive effort
Tractive effort
As used in mechanical engineering, the term tractive force is the pulling or pushing force exerted by a vehicle on another vehicle or object. The term tractive effort is synonymous with tractive force, and is often used in railway engineering to describe the pulling or pushing capability of a...
. The MC-2 rebuilds included installation of a new 4¼-BL Worthington feedwater heater
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 of the system...
as well.
SP used these locomotives until after World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, 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.