Pennsylvania Railroad class S2 No. 6200 in a PRR promotional image.

(By Original uploader was Morven at en.wikipedia - Transferred from en.wikipedia, Public Domain,



A steam turbine locomotive is a steam locomotive which transmits steam power to the wheels via a steam turbine. Numerous attempts at this type of locomotive were made, mostly without success. In the 1930s this type of locomotive was seen as a way both to revitalize steam power and challenge the diesel locomotives then being introduced.


General Electric

General Electric built two steam turbine-electric locomotives with a 2+C-C+2 (4-6-6-4) wheel arrangement for the Union Pacific in 1938. These locomotives essentially operated as mobile steam power plants and were correspondingly complex. They were the only condensing steam locomotives ever used in the United States. A Babcock & Wilcox boiler provided steam, which drove a pair of steam turbines which powered a generator, providing power to the electric traction motors that drove the wheels, as well as providing head-end power for the rest of the train. Boiler control was largely automatic, and the two locomotives could be connected together into a multiple unit, both controlled from a single cab. The boiler was oil-fired, and the fuel was "Bunker C" heavy fuel oil, the same fuel used in large vessels, and also the fuel which was later used in Union Pacific's gas turbine-electric locomotives. Union Pacific accepted the locomotives in 1939, but returned them later that year, citing unsatisfactory results. The GE turbines were used during a motive power shortage on the Great Northern Railway in 1943, and appear to have performed quite well. However, by the end of 1943, the wheels of both locomotives were worn to the point of needing replacement, and one of the locomotive's boilers developed a defect. The locomotives were returned to GE and dismantled.

See main article: GE steam turbine locomotives


Pennsylvania Railroad Direct Drive Steam Locomotive (BLW)

In the waning years of steam, the Baldwin Locomotive Works undertook several attempts at alternative technologies to diesel power. In 1944, Baldwin built the sole example of the S2 class for the Pennsylvania Railroad, delivering it in September 1944. It was the largest direct-drive steam turbine locomotive in the world and had a 6-8-6 wheel arrangement. It was originally designed as a 4-8-4, but due to shortages of lightweight materials during World War II, the S2 required additional leading and trailing wheels. Numbered 6200 on the PRR roster, the S2 had a maximum power output of 6,900 HP (5.1 MW) and was capable of speeds over 100 mph (160 km/h). With the tender, the unit was approximately 123 feet (37 m) long. The steam turbine was a modified marine unit. While the gearing system was simpler than a generator, it had a fatal flaw: the turbine was inefficient at slow speeds. Below about 40 mph (64 km/h) the turbine used enormous amounts of steam and fuel. At high speeds, however, the S2 could propel heavy trains almost effortlessly and efficiently. The smooth turbine drive put far less stress on the track than a normal piston-driven locomotive. However, poor efficiency at slow speeds doomed this turbine, and with diesel-electrics being introduced, no more S2s were built. The locomotive was retired in 1949 and scrapped in May, 1952.

See main article: PRR S2


C&O Railway M1 (BLW)

In 1947–1948 Baldwin built three unusual coal-fired steam turbine-electric locomotives for passenger trains on the Chesapeake & Ohio Railway (C&O). Their designation was M1, but because of their expense and poor performance they acquired the nickname "Sacred Cow". The 6,000 horsepower (4,500 kW) units, which had Westinghouse electrical systems, had a 2-C1+2-C1-B wheel arrangement. They were 106 feet (32 m) long. The cab was in the center with a coal bunker ahead and a conventional boiler behind it, with the tender only carrying water. These locomotives were intended for a route from Washington, D.C. to Cincinnati, Ohio but could never travel the whole route without some sort of failure. Coal dust and water frequently got into the traction motors. While these problems could have been fixed given time, it was obvious that these locomotives would always be expensive to maintain and all three were scrapped in 1950.

See main article: C&O M1


Norfolk & Western Railway Jawn Henry (BLH)

In May 1954 Baldwin-Lima-Hamilton built a 4,500 horsepower (3,400 kW) steam turbine-electric locomotive for freight service on the Norfolk & Western Railway (N&W), nicknamed the Jawn Henry after the legend of John Henry, a rock driller who famously raced against a steam drill and won, only to die immediately after. Length including tenders was 161 ft 1-1/2 inches, probably the record for a steam locomotive; engine-only length was 111 ft 7-1/2 inches, perhaps the record for any single unit.

The unit looked similar to the C&O turbines but differed mechanically; it was a C+C-C+C with a Babcock & Wilcox water-tube boiler with automatic controls. The boiler controls were sometimes problematic, and (as with the C&O turbines) coal dust and water got into the motors. The Jawn Henry was retired from the N&W roster on January 4, 1958.

See main article: N&W 2300