| AT&SF RSD5 (Alco spec. E-1664) 2135 at Colorado Springs, Colorado on August 19, 1964, Kodachrome by Chuck Zeiler. Built in June 1953 (c/n 80604) and delivered in the "zebra stripe" paint scheme, it was renumbered to 9135 August 13, 1970, traded to EMD during 1972 on a SD45-2 order. The month this locomotive was built marked the introduction of the GE Model RD-3 water-cooled turbocharger on Alco's 12-cylinder Model 244 prime mover, which replaced GE's RD-1 air-cooled turbo. The spotting feature is the exhaust stack, which was oriented length-wise to the hood in the case of the RD-1, and cross-wise (as seen here) in the case of the RD-3. The RD-3 was replaced in production during September 1954 with Alco's own design, the Model 510 for 12-cylinder engines and Model 710 for 16-cylinder engines. I have not (yet) figured out what that extra pipe is running along the top of the hood and up the side of the exhaust stack, nor why the numberboard on the short hood was relocated. |