Alco’s initial answer to EMD’s wildly successful FT freight diesel of 1939 was a three-unit locomotive built as a testbed/demonstrator in 1945. Its lines and paint job led observers to dub it “Black Maria,” a slang term for a police wagon. Nos. 1500A, B, and C tested for barely a year on several New England roads, including the New Haven, on which they are pictured with NH Pacific 1384. Classic Trains coll.