In 1959, ALCO introduced the RS-27 with a new design that could later also be found on the Century series. It had a V16 prime mover delivering 2,400 hp. By 1962, 27 had been built of which 15 had gone to the PRR. In 1961 the RS-32 was introduced with a V12 that had an output of only 2,000 hp. 35 were built of which 25 went to the New York Central and ten to the Southern Pacific. The RS-36 introduced in 1962 was an again less powerful variant with only 1,800 hp. Of 40 locomotives built, twelve went to the Delaware & Hudson and eleven to the Nickel Plate Road.