GE announced (I think) that the radial truck wouldbe available as an alternative to the "Roller Blades" non-radial truck on C44-9W, but so far no one wanting a DC-motored GE locomotive has specified that option. (For EMD locomotives, the radial truck is standard: SD70M as well as SD70MAC have it. For GE locomotives, some customers-- CP, CSX, KCS, the mexican railroads-- want the radial truck, but UP continues to get the non-radial truck even on their AC units, and the bi purchasers of C44-9W -- BNSF, NS, CN -- have all been content with roller blades.)
As for CSX's "Dash-9": these units were built at the time of the transition from Dash-8 to Dash-9, and are technological "missing links," with some apomorphic* traits (such as the higher horsepower rating) mixed with some plesiomorphic" traits (like the truck and exterior carbody design).
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*Paleontology and zoology-speak for evolved and primitive, repectively.
