Chesapeake and Ohio class M-1

The Chesapeake and Ohio class M-1 was a fleet of three steam turbine locomotives built by the Baldwin Locomotive Works for the Chesapeake and Ohio Railway in 1947–1948 for service on the Chessie streamliner. As diesel locomotives became more prevalent following World War II, the C&O was one of several railroads that were reluctant to abandon coal as a fuel source, and saw coal-fueled steam turbine technology as a possible alternative to diesel. At the time of its construction, the M-1 was the longest single-unit locomotive in the world.

Chesapeake and Ohio class M-1
Type and origin Power type Steam turbine electric Builder Baldwin Locomotive Works Serial number 73079–73081 Model M-1 Build date 1947–1948 Total produced 3
Specifications Configuration: ​  • Whyte 4-6-2+4-6-2+0-4-0TE  • AAR 2-C1+2-C1-B  • UIC (2'Co1)'(2'Co1Bo')' Gauge 4 ft 8+1⁄2 in (1,435 mm) Driver dia. 40 in (1,016 mm) Length 154 ft 3⁄4 in (46.96 m) Loco weight 857,000 lb (388.7 tonnes)[1]: 161  Total weight 617 tonnes (607.3 long tons; 680.1 short tons) Fuel type Coal Fuel capacity 29.25 short tons (26.54 t) Water cap. 25,000 US gallons (95,000 L; 21,000 imp gal) Boiler pressure 310 psi (2.14 MPa)
Performance figures Maximum speed 100 miles per hour (160 km/h) Power output 6,000 hp (4,470 kW) (turbine)[2]: 141  4,960 hp (3,700 kW) (generators)[3]: 109
Career Operators Chesapeake and Ohio Railway Numbers 500–502 Nicknames Sacred Cow First run 1947 Last run 1949 Scrapped 1950 Disposition All scrapped
[3]: 107–111

Design

The M-1 was a collaboration between the C&O, the Baldwin Locomotive Works, and Westinghouse.^[4]: 202 The C&O possessed substantial coal-hauling revenue and was loath to abandon it as a fuel source.^[5]: 109 Further, C&O's engineering staff expressed concern that oil reserves would be exhausted within 25–30 years.^[3]: 109 The locomotive contained a Westinghouse turbine that drove four direct current (DC) generators, mounted in pairs.^[6]: 116 Each generator produced 1,000 kilowatts (1,300 hp) and collectively powered eight traction motors.^[1]: 161

Unlike typical steam locomotives, the M-1's boiler was in the rear and its coal bunker was in the front. In addition, lacking cylinders, its turbine/generator drive system had fewer moving parts which, in theory, meant that it required far less maintenance than conventional steam locomotives; its designers predicted that it could make a round trip between Washington and Cincinnati without servicing.^{[3]: 110–111}

The locomotive's throttle had 11 settings, ranging from 1 (idle) to 11 (full speed). During a trial run with a reporter from Popular Mechanics aboard, a C&O engineer expressed his dissatisfaction with a local speed limit of 75 miles per hour (121 km/h), noting that he would "sure like to be able to pull [the throttle from position 7] back to 11!"^{[3]: 110, 252} Not including research and development, the three locomotives cost US$1.6 million.^[7]: 45

Use

The C&O cancelled the Chessie in 1948 before it ran in revenue service.^[4]: 202 Unable to fill the role for which they were intended, the M-1s were instead used between Clifton Forge and Charlottesville, Virginia, where they proved expensive to operate and mechanically unreliable before being scrapped in 1950.^{[8]: 62  [2]: 141}

See also

• GE steam turbine locomotives
• Chesapeake and Ohio 490