ALCO 241

The ALCO 241 was a diesel prime mover built by the American Locomotive Company (ALCO). It was the company's first diesel engine originally designed to power road locomotives, with a higher output and operating speed than previous designs.

The introduction of EMC's FT freight diesel in 1939 made Alco management realize that they needed a new diesel engine in order to compete for diesel locomotive sales. The engine that Alco needed must be capable of producing in the range of 1500 horsepower for a freight locomotive and 2000 horsepower for a passenger locomotive. The diesel engine that it did have in 1940, the Alco 539T, would produce approximately 1300 horsepower in an eight cylinder engine. The 539 engine did not have capacity to produce much more than 1300 horsepower. It was not a good candidate for long term locomotive production with capability for greater horsepower.

Design work on the 241, began in 1940, initially led by Ralph Miller, who was shortly thereafter replaced by Paul Vaughan. Alco Engineer Paul Vaughan did a study to recommend a diesel engine specification. His recommendation was for a high speed, 9" X 10.5" V-type diesel engine operating at a maximum of 1,000 rpm with a 45 degree angle between the two cylinder banks. Alco's first attempt at attaining 1500 horsepower in a diesel engine was with the Alco 241 engine program. The 241 engine was approved for development on March 12, 1940. The company authorized both 12 cylinder and 16 cylinder designs. The Alco 241 engine would have a bore (cylinder diameter) of 9 inches (229 mm), and a stroke of 10.5 inches (267 mm). It's designation combines Alco's identifier for that bore and stroke - 2 - with the year its design was approved for laboratory testing - 1941. Alco was focused on creating a diesel engine capable of competing with the EMD FT.

The Alco's design goals for the 241 engine were a high operating speed, a high cylinder output of 135 psi bmep (brake mean effective pressure), a high horsepower to weight ratio, and the capability for growth with later improvements. World War 2 had started and the wartime environment caused all of Alco's businesses to grow. The diesel engine engineering and testing staff had been limited by the previous economic conditions of the Great Depression. Prior to the outbreak of the war the Gulf Mobile & Ohio Railroad ordered 80 diesel freight locomotives from Alco when and if there was a successful design. The additional burden of the war created more work for the Alco diesel engineering staff. This engineering work was mostly to expand production of diesel engines for the U. S. Navy. Effective April 4, 1942 the War Production Board began controlling all industrial production. The Transportation Equipment Branch and the Railroad Advisory Committee both of the War Production Board met on April 8, 1942 to develop a railroad equipment production program for the remainder of the year. This group recommended that diesel locomotive builders build for maximum production. Alco and Baldwin would build diesel switchers and EMD would build freight diesels.. Faced with these considerable difficulties the Alco diesel engineering staff continued the 241 engine project, but at a very slow pace.

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