The General Machinery Corporation management wanted to terminate steam locomotive production, while the Lima management was still committed to the development of a 4-8-6 super steam locomotive, nicknamed "double-bubble" for its unique firebox, designed with poppet valves, to be a true competitor in the diesel market, the design of which began in 1929. By April 1949, the design was shelved, and Lima finished its final steam locomotives a month later. Chief Mechanical Officer Bert Townsend resigned in protest of the decision to scrap the plans to build steam locomotives.
