ALCO S-6

The Alco S-6 (specification DL 430) was a diesel-electric switcher locomotive constructed by ALCO of Schenectady, New York; a total of 126 locomotives were built between May 1955 and December 1960. The S-6 was an improved version of the earlier S-5.

Design
Visually indistinguishable from the S-5, the S-6 used an ALCO 251A or 251B prime mover rated at 900 hp. The locomotive rode on two-axle AAR trucks, giving a B-B wheel arrangement. ALCO produced a cow-calf variant for the Oliver Iron Mining Company designated SB-8/SSB-9, two sets were produced of this version.

In popular culture

 * In Back to the Future Part III, two double headed S-6 locomotives destroyed the DeLorean time machine, when it returned to 1985.