EMD FT

The EMD FT emerged from the Electro-Motive Corporation's ambition to prove that diesel-electric power could supplant steam on heavy freight assignments. The four-unit demonstrator set, completed in late 1939, toured railroads across the United States over the following year, accumulating thousands of miles across mountain grades, desert stretches, and flatland main lines. This tour served as a prolonged audition, and the results persuaded a skeptical industry that diesel traction was not merely viable for passenger service but could handle the most demanding freight operations. The demonstrator set was eventually sold to the Southern Railway in May 1941, after its prototype engines had been replaced with production-specification powerplants. Commercial production began with units delivered to the Atchison, Topeka and Santa Fe Railway in late 1940 and early 1941, and that road ultimately became the largest operator of the type. The Santa Fe's particular operating environment, with long desert divisions where water for steam locomotives was scarce and expensive to supply, made the FT especially attractive, and the War Production Board recognized this when allocating wartime locomotive production. Because Electro-Motive was exclusively a diesel builder, it was permitted to continue FT production throughout World War II while competing manufacturers such as Baldwin and Alco were largely restricted from building diesel road locomotives until early 1945. This circumstance gave EMD an enormous competitive advantage in the postwar market, as the company emerged from the war years with a mature and proven product while rivals scrambled to develop comparable diesel road locomotives under intense pressure. Production of the FT continued until November 1945, with a total of 555 cab-equipped A units and 541 cabless B units completed, all of them sold to American railroads. The FT's legacy extends well beyond its production numbers. It fundamentally altered the trajectory of American railroad motive power by demonstrating conclusively that diesel-electric locomotives could handle tonnage freight at a lower operating cost than steam. The Blomberg B truck introduced with the FT became EMD's standard freight truck and remained in use for decades afterward. The 567 series engine that powered the FT continued in production until 1966, evolving through successive variants to power much of EMD's postwar locomotive output. Railroad historians widely regard the FT as one of the most consequential locomotive designs ever built, marking the point at which the transition from steam to diesel in the United States became effectively inevitable.

Each FT unit was powered by a single EMD 567 series sixteen-cylinder two-stroke diesel engine producing 1,350 horsepower at 800 rpm. The engine used a Roots-type blower for scavenging and featured a 45-degree V configuration with a bore of 8.5 inches and a stroke of 10 inches, yielding 567 cubic inches of displacement per cylinder, the figure from which the engine series took its name. The four demonstrator units originally carried the 567 U-Deck variant, but these were replaced with V-Deck engines before the set was sold. All customer units built through February 1943 used the 567 V-Deck engine, after which the updated 567A variant was adopted for the remainder of production. Power from the engine was transmitted through a D8 DC generator to four D7 traction motors arranged in a B-B wheel configuration, with two motors per truck and one per axle. Units were typically delivered as semi-permanently coupled A-B pairs joined by a solid drawbar, forming a single 2,700-horsepower locomotive, and many railroads operated two such pairs back to back in an A-B-B-A arrangement for a combined output of 5,400 horsepower manageable from a single cab through multiple-unit control. Visually, the FT can be distinguished from its F-unit successors by several details. Four exhaust stacks ran along the roof centerline, and the radiator fans were recessed into the carbody and arranged in two pairs positioned near opposite ends of the unit rather than grouped together as on later models. The side of the carbody featured four closely spaced porthole windows, with a fifth porthole provided on B units equipped with hostler controls, which allowed those units to be operated independently within yard limits. The body itself served as a structural element in the manner of a truss, a design philosophy shared with other early cab units of the period. The Santa Fe, which ordered its FTs with conventional couplers on both ends of each unit for operational flexibility rather than the standard solid drawbar connection, received units that EMD internally designated as the FS model, a distinction that influenced how that railroad organized its locomotive consists differently from most other operators.

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Models by: Intermountain