Builder’s portrait of a Soo Line EMD F3 diesel locomotive. The EMD F3 was a 1,500-hp freight- and passenger-hauling diesel locomotive produced between July 1945 and February 1949 by General Motors’ Electro-Motive Division. Final assembly was at GM-EMD’s La Grange, Illinois plant. A total of 1,111 cab-equipped lead A units and 696 cabless booster B units were built. The F3 was the third model in GM-EMD’s highly successful F-unit series of cab unit diesel locomotives, and it was the second most produced of the series. The F3 essentially differed from the EMD F2 in that it used the “new” D12 generator to produce more power. As built, the only way to distinguish between the F2 and F3 was the nose number panels on the A units, which were small on the F2 and large on the F3. The Soo Line acquired 10 of the A units, numbered 200A, B – 204A, B.