EMC 1800 hp B-B

EMC Demonstrators

EMC demonstrator #511 on the CB&Q in 1937. The locomotive is painted silver, to serve as a backup for CB&Q's Zephyr and AT&SF's Super Chief locomotives.

Type and origin Power type Diesel-electric Builder General Electric (EMC design) Serial number 511–512 Build date August 1935 Total produced 2

Specifications

Career Numbers 511–512 Official name 1800 hp B-B Locale North America Disposition Scrapped

Baltimore & Ohio #50

In 1972 at the EMD plant.

Type and origin Power type Diesel-electric Builder General Electric (EMC design) Serial number 532 Build date August 1935 Total produced 1

Specifications

Career Operators Baltimore and Ohio Railroad Chicago and Alton Railroad Gulf, Mobile and Ohio Railroad Numbers B&O 50 C&A 50 GM&O 1200 Official name 1800 hp B-B Locale North America Current owner Museum of Transportation, St. Louis, Missouri Disposition Museum artifact

Electro-Motive Corporation (later Electro-Motive Division, General Motors) produced five 1800 hp B-B experimental passenger train-hauling Diesel locomotives in 1935; two company-owned demonstrators, #511 and #512, the Baltimore and Ohio Railroad's #50, and two units for the Atchison, Topeka and Santa Fe Railway, Diesel Locomotive #1. The twin engine power unit layout and multiple unit control systems developed with the B-B locomotives were soon adopted for other locomotives such as the Burlington Route's Zephyr locomotives built by the Budd Company in 1936 and EMC's own E-units introduced in 1937. The B-B locomotives worked as proof-of-concept demonstrators for Diesel power with the service loads of full size trains, breaking out of its niche powering the smaller custom streamliners.

In 1935 EMC was starting its transition from a design and marketing company to a locomotive building company; development of regular production model locomotives was occurring before they had the capability to build locomotives. Construction of carbodies for EMC demonstrators #511 and #512, and B&O #50 was contracted to GE's Erie, Pennsylvania works, and AT&SF #1 was contracted to St. Louis Car Company. Like most boxcabs, they initially had control cabs at both ends, a feature that would only rarely be repeated in future North American locomotives, although it would become common elsewhere. Power was provided by twin 900 hp (670 kW) 12 cylinder Winton 201-A Diesel engines in each power unit, exceeding by 50% the most power that could be attained with a single engine at that time. The added "headroom" in power extended the life of mechanical parts, which was a critical issue with early Diesel engines in locomotives. The units were built with AAR type B two-axle trucks instead of the A1A trucks of E-units. As development design locomotives, modifications were frequently made to them to overcome various teething problems; the EMC demonstrators spent considerable time in aluminum paint substituting for the units under modification.