ALCO RSD-15
The Alco RSD-15 is a diesel-electric locomotive built by the American Locomotive Company (ALCO) of Schenectady, New York between August 1956 and June 1960, during which time 75 locomotives were produced. The RSD-15 was powered by an Alco 251 16-cylinder four-cycle V-type prime mover rated at ; it superseded the almost identical Alco 244-engined RSD-7, and was catalogued alongside the similar but smaller RSD-12, powered by a 12-cylinder 251-model V-type diesel engine. The locomotive rode on a pair of three-axle "Trimount" trucks with all axles powered by General Electric model  752 traction motors. These trucks have an asymmetrical axle spacing because of the positioning of the traction motors. The six-motor design allowed higher tractive effort at lower speeds than an otherwise similar four-motor design. The RSD-15 could be ordered with either a high or low short hood; railfans dubbed the low short hood version "Alligators", due to their unusually long low noses. RSD-17. A single example of the very similar model RSD-17 was built by the Montreal Locomotive Works in 1957. After demonstrating on the Canadian Pacific "(as #7007)", the Canadian National "(as #3899)", and the Pacific Great  Eastern "(as #624)", the locomotive was purchased by the Canadian Pacific "(as #8921)". Nicknamed "The Empress of Agincourt", by Pete Fairfull, who was its primary operator for many years, "(for its common presence around Toronto's Agincourt yard)", the locomotive served the railway until 1995, when truck problems forced its retirement. Surviving examples. Six RSD-15s survive in preservation; all are ex-Santa Fe units. Only two are in operating condition; the Austin and Texas Central #442, originally ATSF 842, painted in a modified Southern Pacific "Black Widow" scheme, and Green Bay and Western Railroad RSD-15 #2407 (originally ATSF 841) at  the Illinois Railway Museum. Others that are preserved are Santa Fe 823, in second owner Utah Railway colors at the Utah Railroad Museum, the California State Railroad Museum in Sacramento has one (Santa Fe #9820) and the Arkansas Railroad Museum has Santa Fe #843. The RSD-17 demonstrator, Canadian Pacific 8921, is preserved at the Elgin County Railway Museum, St. Thomas, Ontario, Canada. Models. The RSD-15 has been produced in N scale by Mehano of Yugoslavia and Broadway Limited of the United States. The RSD-15 has been produced in HO scale by Broadway Limited Imports and handmade brass. Alco Models (DL600b ) high and Low hoods. Also (Overland Models). The RSD-15 has been produced in O scale by Atlas O in their Trainman line. The RSD-17 has not been mass-produced in any scale; however, in 2008 Broadway Limited Imports did produce a limited run of the high-hood CP 8921 in HO scale.