The Southern Pacific 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 Southern Pacific Railroad, Southern Pacific Company and Southern Pacific Transportation Company.
Under the Whyte notation for the classification of locomotives, 4-6-4 represents the wheel arrangement of four leading wheels, six powered and coupled driving wheels and four trailing wheels. In France where the type was first used, it is known as the Baltic while it became known as the Hudson in most of North America.
Under the Whyte notation for the classification of steam locomotives, 4-8-4 represents the wheel arrangement of four leading wheels on two axles, eight powered and coupled driving wheels on four axles and four trailing wheels on two axles. The type was first used by the Northern Pacific Railway, and initially named the Northern Pacific, but railfans and railroad employees have shortened the name since its introduction. It is most-commonly known as a Northern.
Under the Whyte notation for the classification of steam locomotives, 2-10-2 represents the wheel arrangement of two leading wheels, ten powered and coupled driving wheels, and two trailing wheels. In the United States and elsewhere the 2-10-2 is known as the Santa Fe type, after the Atchison, Topeka and Santa Fe Railway that first used the type in 1903.
Under the Whyte notation for the classification of steam locomotives by wheel arrangement, 4-10-2 represents the arrangement of four leading wheels, ten powered and coupled driving wheels and two trailing wheels. In South Africa, where the wheel arrangement was first used, the type was known as a Reid Tenwheeler. In the United States of America it was known as a Southern Pacific on the Southern Pacific Railroad and as an Overland on the Union Pacific Railroad.
The term cab forward locomotive refers to various rail and road vehicle designs that place the driver's compartment substantially farther towards the front than is common practice.
The Southern Pacific GS-4 is a class of semi-streamlined 4-8-4 "Northern" type steam locomotive operated by the Southern Pacific Railroad (SP) from 1941 to 1958. A total of twenty-eight were built by the Lima Locomotive Works, numbered 4430 through 4457. GS stands for "Golden State" or "General Service."
The GS-5 was a class of streamlined 4-8-4 "Northern" type steam locomotive operated by the Southern Pacific Railroad (SP) from 1942 to 1958. A total of two were built by the Lima Locomotive Works, numbered 4458 and 4459. GS stands for "Golden State" or "General Service."
Southern Pacific 4460 is the only surviving class "GS-6" steam locomotive, together with "GS-4" class Southern Pacific 4449, which is operational in excursion service. The GS-6 is a semi-streamlined 4-8-4 "Northern" type steam locomotive. GS stands for "Golden State" or "General Service". The locomotive was built by the Lima Locomotive Works (LLW) for the Southern Pacific Railroad (SP) in 1943. The GS-6 lacked side skirting and red and orange "Daylight" paint found on previous locomotives of the GS class and were painted black and silver instead. The War Production Board controlled locomotive manufacturers during World War II and had turned down Southern Pacific's order of fourteen new Daylight locomotives in 1942. Southern Pacific re-designed the new fleet based on the older GS-2s, only with 260 psi instead of 300 psi, an all-weather cab, and a new GS-4 style tender. The design was finally approved, but the War Production Board reassigned four to the smaller and power-starved Western Pacific Railroad. Their smaller size when compared to previous GS class locomotives and the fact that they were built during World War II earned them the nicknames "War Babies".
Southern Pacific Railroad's AC-7 class of cab forward steam locomotives was the fourth class of the 4-8-8-2 locomotives purchased by Southern Pacific (SP). The locomotives were built by Baldwin Locomotive Works and shared many of the same characteristics of previous AC class locomotives.
Southern Pacific Railroad's AC-8 class of cab forward steam locomotives was the fifth of SP's 4-8-8-2 classes. They were built by Baldwin Locomotive Works in 1939.
Southern Pacific Railroad's AC-11 class of cab forward steam locomotives was the seventh class of 4-8-8-2 locomotives ordered by Southern Pacific (SP) from Baldwin Locomotive Works; SP was so pleased with the AC-10 class built a year earlier that the railroad began placing orders for AC-11s while the AC-10s were still being built and delivered. They were built between November 1942 and April 1943, closely resembling the AC-10s.
Southern Pacific Railroad's AC-12 class of simple articulated 4-8-8-2 cab forward steam locomotives was the last class of steam locomotives ordered by Southern Pacific. They were built by Baldwin Locomotive Works during World War II, with the first, number 4275, entering service on October 27, 1943, and the last, 4294, on March 19, 1944. The locomotives were effectively a conventional 2-8-8-4 locomotive running in reverse; the tender being coupled at the smokebox end of the locomotive. This was made possible by the use of oil-firing. The distinct features of these locomotives include: a streamlined front with white band, an air horn on the front, a streamlined pilot, a SP 12 wheel box tender, and air compressors mounted on the smokebox. Southern Pacific used these locomotives all over its system, but they were extremely famous for working on Donner Pass & Cascade Summit.
Southern Pacific 4294 is a class "AC-12" 4-8-8-2 Cab forward type steam locomotive that was owned and operated by the Southern Pacific Railroad (SP). It was built by the Baldwin Locomotive Works in March 1944 and was used hauling SP's trains over the Sierra Nevada, often working on Donner Pass in California. Today it is preserved at the California State Railroad Museum (CSRM) in Sacramento, California.
Southern Pacific Company's MM-2 class of steam locomotives was one of Southern Pacific's (SP) only classes of 2-6-6-2 locomotives ordered and built as oil-fired cab forward locomotives. They were built in 1911 as compound-expansion Mallet locomotives by Baldwin Locomotive Works and entered service on SP beginning September 19, 1911. By 1914, they had all been upgraded with an additional leading axle making them 4-6-6-2 locomotives, reclassified from MM-2 to AM-2. This was done to improve handling at speed. These locomotives were the predecessors of several other cab-forward engines, culminating in the AC-12 class cab forward locomotives built during World War II.
Southern Pacific Railroad's MC-2 class of steam locomotives 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.
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 locomotives in late 1909. The AC-1 class was the first of the successful AC series of cab forward locomotives that numbered nearly 200 in total on the SP. Southern Pacific No. 4002 was rebuilt in June 1923 as a Cab Forward.
Southern Pacific Company's MC-6 class of steam locomotives is made up of two batches: the first consisting of 15 locomotives weighing 435,800 pounds built in 1912, the second consisting of 5 locomotives weighing 437,100 lb built in 1913. All of the locomotives were built by Baldwin Locomotive Works. This was the last class of 2-8-8-2 locomotives that Southern Pacific (SP) ordered as cab forward locomotives.
Southern Pacific Company's AM-2 class of steam locomotives was Southern Pacific's (SP) only class of 4-6-6-2 locomotives ordered and built as cab forward locomotives. They were actually MM-2s that had been upgraded. MM-2s were built in 1911 by Baldwin Locomotive Works and entered service on SP beginning September 19, 1911. By 1914, they had all been upgraded with an additional leading axle making them 4-6-6-2 locomotives. They reclassified their MM-2 as AM-2. This was done to improve handling at speed. These locomotives were the predecessors of the AC-12 class cab forward locomotives built during World War II.
Southern Pacific No. 1744 is a preserved American class "M-6" 2-6-0 "Mogul" type steam locomotive built by the Baldwin Locomotive Works for the Southern Pacific Railroad in November 1901. Originally equipped with Vauclain compound cylinders, it was rebuilt with conventional cylinders in 1912. It operated for many years out of Oakland, California on the Southern Pacific's Western Division and in California's Central Valley where the locomotive and its classmates were fondly called “Valley Mallets” by their crews. The locomotive was made famous in later years by pulling some of the last steam excursions on the SP alongside other steam locomotives, including 4-8-4 4460. In 1959, No. 1744 was donated to the Sons of Utah Pioneers in Corinne, Utah where it remained on static display, until 1980. That year, it was restored by New London Railroad and Village Incorporated to operate on the Heber Valley Railroad in Heber City for the rest of the decade.
