Discussion in 'Trainspotter ID' started by Triplex, Oct 1, 2006.

  1. Triplex

    Triplex Active Member

    Aug 24, 2005
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    EMD followed the SD80MAC with the SD90 series, designed to have 6000 horsepower from a single prime mover.

    The new "H-engine" wasn't ready, so the first SD90s were SD9043MACs. These used the engine from the SD70 series and were effectively SD70MACs, but they were designed for a quick upgrade with an H-engine when it was ready. The SD9043MAC looks almost identical to the SD80MAC.

    Note the lack of a notch in the rear:

    More photos:

    CP SD9043MAC:

    A&O (ex-CEFX) SD9043MAC:

    Two UP SD9043MACS frame a GE unit:

    However, when the H-engine became ready, the new engines built with it did not look identical to SD9043MACs. The SD90MAC-H, as it was termed, was ordered only by Union Pacific.

    It can be distinguished by its roofline. Note the sloped sides above the engine compartment:

    The SD90MAC-H II (SD90MAC-H Phase 2) followed.

    Note the new cab, with rectangular front windows and notched nose. Also observe the flared radiators. In addition to having three large sections, note the two small sections behind them.

    SD80MACs, SD9043MACs, and SD90MAC-Hs had three fans above the flares and one behind. SD90MAC-H IIs have only two above the flares and one behind:

    It was delivered mostly to UP, but CP received 4 units. The UP units were returned to EMD, which leases them to KCS.

    SD90MAC-H II and SD9043MAC together:

    All of these engines are frequently just called SD90MACs. Also, photos frequently mislabel one subtype as another. Only trust the actual identifying features.