Western Pacific 2-6-6-2 "Mallet Mogul" Locomotives in the USA

Class M-80 (Locobase 3101)

Data from WP All-Time Steam Locomotive Diagrams supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange collection. See also Guy Dunscomb, Album of Western Locomotives (Modesto, Calif: Guy Dunscomb, 1952), p. 55.

Frank Brehm's roster at [] (accessed 3 July 2006) gives details of the class: Five were built by Brooks in 1917 (works numbers 57444-57448) for $52,861 each and five more came from Richmond in 1924 (works numbers 65485-65489). Wartime inflation had taken its toll, however -- unit price for this quintet was $83,405.

Firebox heating surface originally included 26 sq ft (2.42 sq m) of arch tubes and amounted to 386 sq ft. (35.86 sq m) The later heating surface value shown in the specs included 84 sq ft (7.8 sq m) of thermic syphons in the firebox and combustion chamber. 14" (356 mm) piston valves supplied steam to the HP cylinders; LP cylinders used slide valves.

They originally took on the Feather River Canyon run between Oroville and Portola, Calif. M-137 s, which could take singly trains that required an M-80 and an MK-60 together, replaced the M-80s in 1931. The

Still useful, the class then ran over the Northern California Extension--203 miles (324 km) of railway between Keddie and Bieber, "through the least inhabited and most beautiful parts of California," wrote Guy Dunscombe, until the end of steam.