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 . 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.
Original owners RailroadQuantityRoad NumberNotesAllied Chemical Company1110ARMCO Steel11202B. Perini & Sons Construction Company1101to Upper Merion and Plymouth Railroad 101Belt Railway of Chicago1420Ferrocarril Chihuahua al Pacífico160Renumbered 106Cia Fundidora de Hierro y Acero31–3Ferrocarril del Pacífico24701–723Ferrocarriles Nacionales de México15300Northern Pacific Railway1750to Burlington Northern Railroad 950Ohio River Company (ORCo)156Republic Steel3153, 317, 318Secretaria de Comunicaciones de Obras Publicas (SCOP)37133-1, 2, 3 to Ferrocarril del Sureste (same numbers)Sheffield Steel215, 16Southern Pacific Railroad701033–1082, 4634–4645 renumbered 1200–1257, 1270–1281South Buffalo Railway640–45Tennessee Copper1107Upper Merion and Plymouth Railroad161U.S. Pipe and Foundry138Columbia Geneva Steel11Western Maryland Railway2151, 152Ferrocarriles Unidos de Yucatán1301
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. The lead engine is currently in the possession of the Virginia and Truckee Railroad
See also List of ALCO diesel locomotives List of MLW diesel locomotives
References
External links
Sarberenyi, Robert. Alco S5, S6, and SSB9 Original Owners.