SW9 311 and GP35 729 by Frisco.org Posted on January 14, 2015 SW9 311 and GP35 729 SW9 311 and GP35 729 at Springfield, Missouri in August 1977. Locomotive 704 is also a GP35. The units are sitting on the east side of the engine house and the photograph was taken from the Kansas Avenue Bridge. Special thanks to Karl Brand. This entry was posted in Slides and tagged 311, 704, 729, Electro-Motive Division, GP35, SW9. Bookmark the permalink.