Burlington Northern SD45 & F45
The SD45 was a power-house locomotive. General Motors built 1,260 between 1965 and 1971. The SD45 has a 20-cylinder, 3600 horsepower engine. Because the engine block was 2-pistons longer than the popular 16-cylinder engine block, the engine block would flex and twist causing the longer crankshaft to break. The traction effort of the SD45 was about the same as a SD40, so it did not make that much of an advantage.
Only one variation of the SD45 was made--the SDP45. This was a passenger version that had a steam generator on board to heat and cool the passenger cars. The Great Northern was the only railroad to buy the passenger version.
Then from 1972 to 1974, 136 SD45-2s were built. EMD only made one variation of the SD45-2--the SD45T-2. Built from 1972 to 1975, only 247 were made for the Southern Pacific and Cotton Belt.
Great Northern purchased 27 (400-426), Northern Pacific purchased 50 (3600-3649) SD45s. NP 3630-3649 were delivered after the 1970 BN merger. Then Burlington Northern ordered 167 SD45s of its own.
BN 6400 to 6429 were former NP, the 6430 to 6456 were former GN, and the 6457 to 6471 were former CB&Q. The 6472 to 6491 were ordered by the NP but delivered as BN units. The 6492 to 6497 were ordered by the CB&Q but delivered as BN units. Engines 6498 to 6576 were purchased by Burlington Northern.
The F45 was just an SD45 with a full-width cowl carbody. Built from 1968 to 1971, this style of carbody was suppose to improve fuel economy by reducing wind drag. GN loved the idea and loved the looks of the F45. Their plan was to have a F45/SD45/F45 pulling every freight train. GN bought 14 F45s, Burlington Northern bought 23 of their own after the merger. There was a passenger version, the FP45. The Santa Fe was the only railroad to buy that model.