Union Pacific SD9043MAC

Union Pacific SD9043MAC

Union Pacific SD9043MAC

The SD9043MAC is the 4300 hp SD90 unit. These units were purchased with a 4300 hp prime mover, with the intention of converting them to 6000 hp units when the 6000 hp prime mover had been fully tested. However U.P. did not have a good experience with the initial 6000 hp units, so these units were never converted and remain at 4300 hp.

The major spotting characteristic is the engine compartment, which is square, rather than beveled, as it is on the 6000 hp units. The ten doors are also arranged in a 4-6 configuration, rather than a 2-4-4 configuration as in the SD90MAC-H. The engine compartment doors are also about six inches higher on the SD9043MAC, and there is only one exhaust vent on the SD9043MAC.

Union Pacific has 309 units and the prototypical running numbers are 8000-8308.

Union Pacific SD9043MAC