Actually..... That's an SD40E. Basically, the SD40Es were once SD50s (which were similar to the SD60 and the one-of-a-kind SD70 top-hats), but most, if not all, were rebuilt as SD40Es. They keep the same 645 engine and same cosmetic appearance, except that they have new horsehead paint, new electronics, including PTC/NS LEADER, among other upgrades. The SD60s, however, keep the same appearance as the SD50 (albeit slightly longer), however they have 710 engines, newer technology, and didn't come with the same issues the SD50s had. Some even came from Conrail. And furthermore, the SD60s were numbered in the 6500-6700 series, including the ex-conrails (not counting the 60Is and 60Ms), while the SD40Es were numbered in the 6300 series. Bottom line: what you saw there was an SD40E. The SD60s are long-gone now unfortunately, and the SD40Es have been, for the most part, replaced on helper detail by the SD70ACUs and some of the C6Ms, so they're on locals and maintenance detail now. Doesn't mean retirement yet, but it does mean they're doing other work.
