I don't have a lot of photos of them but I happened to photograph the three models we have here.
So welcome ALCoholics and upload your pictures too.

She is one of the oldest, a RSD-16 from the fifties. Picture was taken in Melincué, Santa Fe province.


This one we call her "alquito" (little ALCo), a RSD-35. Her engine was changed recently and that's why she has a dome, the picture was taken in Coronel Dorrego, Buenos Aires province.

And she is the other "alquito", a RSD-39. Unlike the others, she wasn't part of the originally bought ALCos from Argentina, this one was purchased from Spain in the nineties by one of the 'new' private operator of suburban railroads and regauged (idk if this word exists in english but you can imagine what it means) from 1668mm (5' 5,70") to 1676mm (5' 6"). Zárate, Buenos Aires, province where the tracks looks very different today as it was fully renewed (finally).