Bluegrass Railroad Museum

The Korean War and the intensification of the Cold War at the beginning of the 1950s caused the United States Army Transportation Corps to consider what it might need for a new land war in Europe. They came up with a requirement for a locomotive capable of running on the existing tracks of a wide variety of railway systems. Key parts of the specification included adjustable-gauge trucks, compact bodywork to fit restrictive loading gauges, and replaceable couplers to fit a variety of systems. The trucks accepted wheelsets between standard gauge 4 ft 8 1/2 in (1,435 mm) and 5 ft 6 in (1,676 mm), which encompasses the vast majority of the broad gauges in use worldwide, including those of the then Soviet Union and the Iberian peninsula. Both [Alco and General Electric] delivered their sample batch in 1952, and after testing the GE locomotives, which were actually produced by Alco as a subcontractor, the Alcos were declared the winner, and a further batch of 70 ALCO MRS-1 locomotives were ordered.

The initial fate of most of the MRS-1 locomotives was to be placed in storage at the USATC's Transportation Materiel Command facility at Marietta, Pennsylvania, awaiting a war to use them in; they had not been purchased for peacetime use. These brand-new locomotives, with at most a couple of weeks' actual use, sat preserved until approximately 1970, when the Pentagon concluded that their plans for a future, large-scale land war no longer included the capture and use of the enemy's railway system. Thus the 96 locomotives were redundant for their original purpose. Many of the units were taken out of storage and assigned to various military installations around the country, where locomotives of that size and power were required. The Army eventually decided to transfer the units to the United States Navy. Five units stationed in Concord, California were the last to be used by the armed forces.

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