ExEMDLOCOTester-A little more information that I've been able to uncover, one on a locomotive builder and a couple of asides I hope you'll find of interest...
Lima Locomotive Works-In addition to producing locomotives, Lima was also involved in the production of M4 Sherman tanks and built 1,655 of them before war's end. See:
http://www.bluffton.edu/courses/TLC/BushP/LLW-0.html
Lionel Toy Company-Geared up for the war effort and by the time Pearl Harbor was bombed (Dec. 7th, 1941) Lionel already had $5.5 million in government contracts. Train production was suspended in June of 1942. Lionel produced Navy compasses and compensating binnacles, torpedo directors, wind velocity and direction measuring instruments and peloruses among other items. The military cancelled all contracts with Lionel the day after the Hiroshima bombing in August of 1945, and the factory retooled for peace time production, with toy trains again being made by October of 1945.
(Incidentally, Lionel also had contracts with the Navy and Signal Corps during WWI, producing compasses, binnacles and signal and navigating equipment.)
The Military Railway Service-Approximately 43,500 experienced American railroaders were organized in the Military Railway Service with the MRS handling rail operations in:
North Africa, 1943-1944
Iran, 1942-1945
India, 1943-1945
The Philippines, New Caledonia, Australia and Japan, 1942-1945
Sicily and France, 1943-1945
Northern and Southern France and Belgium, 1944-1945
Germany, 1944-1946
Additionally, the 714th Railway Operating Battalion of the Army Transportation Corps operated the Alaska Railroad from April, 1943 through May, 1945.
The White Pass and Yukon Railroad was leased to the U.S.Army in Oct. 1942 and was operated by Army personnel (770th Railway Operating Battalion) until war's end. Part of the impetus for this was the construction of the Al-Can Highway and the heavy demands for traffic capacity on what was, in 1942, a practically worn out railroad with less than a dozen operating locomotives at the start of the war. The WP&Y ended up acquiring a roster of veritible museum pieces including locos from the Eastern Tennessee and Western North Carolina (Tweetsie), Colorado & Southern, Silverton and Northern and the Denver and Rio Grande Western as well as ten meter-gauge 2-8-2's that were originally destinied for Iran but were diverted to the WP&Y and regauged to the WP&Y's 3-foot gauge.