The B&O's class P-6a 4-6-2s were Baldwin products of 1923, based on the USRA light Pacific design. They had 74-inch drivers and cylinder dimensions of 25x28 inches, and (after 1932) sustained 210 p.s.i. of boiler pressure. With 3331 square feet of evaporative heating surface, they had 794 square feet of superheater surface and a grate area of nearly 67 square feet. Weighing 288,600 pounds, they developed 42,213 pounds of tractive effort. By the end of 1957 all members of the class had been retired. No. 5243 of the class poses here at Cincinnati, Ohio in an undated postcard view by R. J. Foster acquired through eBay.