Burlington Northern The Burlington Northern was the result of a merger of several railroads including the Great Northern, Northern Pacific, and Spokane Portland & Seattle. Upon completion of the merger, BN found itself depending on a fleet of inherited F-Units. Originally numbered in the 9700 series for passenger service, the BN F3's that remained on the roster were soon renumbered in the low 700 series. In the BN numbering scheme, A-units wore even numbers and B-units wore odds. The road numbers we have selected are former GN and SP&S locomotives.