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The ALCO RSD-16 is a diesel locomotive, built by American Locomotive Company. The engine weights approximately 108 tonnes (106.3 imperial tons). The locomotive is used exclusively on railroads in Argentina having been built for use on the broad gauge routes in the country.
The 30 locomotives that Ferrocarril Nacional Domingo Faustino Sarmiento owned were not well suited for that line due to a lack of on-line traffic. From 1964 to 1967, 20 of those engines were leased to the San Martín line although they would later return to the Sarmiento. During the same era, several engines from the Mitre and San Martín were loaned to the Ferrocarril Nacional General Roca where they were put in use between Mar del Plata and San Carlos de Bariloche.
During the 1970s the RSD-16's were heavily used in services between Córdoba, Rosario, Mendoza, Santa Rosa, and the resorts in Mar del Plata.
In 1978, one engine was rebuilt with a FIAT A-230-12 diesel engine replacing the original ALCO 251 engine block. In 1980/1981, 16 other locomotives were rebuilt with 251-C MLW engines imported from Canada. Materfer would later use shop space at an Electro-Motive Diesel plant in Argentina to build new engine blocks for use in the RSD-16's.
ALCO RSD-16 on the NCA (Nuevo Central Argentino) railroad.