The Chesapeake & Ohio was a substantial coal hauler, and one of the last major North American railroads to join the rush to dieselization. In addition to ordering one of the most advanced 4-8-4 designs, the J-3a class of 1948 (see No. 610 following), the railroad experimented with a streamlined steam turbine electric locomotive. Built in 1947-48 by Baldwin Locomotive Works in cooperation with Westinghouse Electric Corporation, the M-1 class consisted of three locomotives, Nos. 500-502. These turbines were of the 4-8-0+4-8-4 wheel arrangement — or, more correctly in conventional electric traction notation, the 2-C1-2-C1-B arrangement since only three axles on the eight-wheel trucks were powered. Designed for speeds up to 100 miles per hour, they were intended for the C&O's projected Chessie streamliner, but the train never materialized and they spent their brief careers in more mundane service. This image was scanned from the 1951 edition of World Railways.