Baldwin Locomotive Works produced several different Baldwin DR-6 models of 6-axle passenger train-hauling diesel locomotives between 1945 and 1948. The series comprised eight individual versions, all of which sold only in small numbers; across all versions, only 39 locomotives were produced. Each version was produced only for a single railroad. Many shared the same Baldwin model number, DR-6-4-2000, even though they were rather different; this was because the Baldwin model only encoded the total axles (6), the driven axles (4) and the power output (2,000 hp or 1,500 kW). The single exception was the single unit produced for the Chicago and North Western Railway, which had a single 1,000 hp (750 kW) engine and was model number DR-6-2-1000. In the AAR wheel arrangement scheme of classification, these locomotives were of A1A-A1A and A1A-3 arrangements, respectively.
The first produced version comprised a pair of DR-6-4-2000 demonstrators built in 1945. This, unlike later models, used Baldwin's VO engine model. These locomotives had a unique cab that featured the same upright, aggressive prow as the 30 Baldwin C-C units built on a U.S. Army order in 1945 for shipment to the U.S.S.R. as part of Lend-Lease. They emerged as Baldwin #2000 and #2001. After demonstrating on a number of railroads, they were sold to Ferrocarriles Nacionales de México (NdeM) and assigned road #6000 and #6001.
608NA-engined DR-6-4-20 locomotives
Three different railroads ordered the DR-6-4-2000 model with the 608NA 8-cylinder naturally aspirated engine, but in visually different forms.
The Central Railroad of New Jersey ordered six DR-6-4-2000 locomotives, #2000–#2005, which were unusual for North American diesel locomotives in that they had driving cabs at both ends. They were thus nicknamed "Janus" locomotives, after the two-faced Roman god of the same name. The cab style was nicknamed "Babyface" and was used by several other Baldwin models. The original paint scheme was a deep, rich blue on the lower part of the locomotive and a golden yellow on the upper part.
The Gulf, Mobile and Ohio Railroad ordered two locomotives, road #280 and #281. These were delivered in a single-ended "babyface" carbody.
The Ferrocarriles Nacionales de México ordered one additional DR-6-4-2000 unit after purchasing the two demonstrators. This was assigned road #6002 and had nearly identical styling to the demonstrators, but used two 608NA engines instead of their VO power plants.
606SC-engined DR-6-4-2000 locomotives
These were produced exclusively for the Pennsylvania Railroad and were delivered in 1948 in the sharknose body style designed by Raymond Loewy, as diesel running mates to the T1 steam locomotive; also built by Baldwin and similarly styled by Loewy. Eighteen A units and nine B units were produced, producing nine three-unit locomotive sets of 6,000 horsepower (4,500 kW). The PRR classified them as BP-20 (Baldwin Passenger, 2,000 horsepower or 1,500 kilowatts). They were originally used on top-flight express trains such as the Broadway Limited, but problems soon relegated them to lesser service. They ended their days on commuter trains along the New York and Long Branch in New Jersey. A small number were de-rated for use in freight service (re-classified as BF16z).
A single DR-6-2-1000 locomotive of A1A-3 wheel arrangement was produced for the Chicago and North Western Railway and assigned road #5000. This contained only a single 606SC engine of 1,000 horsepower (750 kW); the rear engine compartment was replaced by a baggage compartment as it hauled mostly local trains. Other locomotive units like this included the Chicago, Rock Island and Pacific Railroad's EMC AB6 in their original form.
608SC-engined DR-6-4-1500 locomotives
Baldwin also built “Babyface” A1A-A1A units with a single 608SC engine of 1,500 horsepower (1.12 MW). Seven cab-equipped locomotives were built—four for the New York Central Railroad (#3200–3203), and three for the Seaboard Air Line Railroad (#2700–2702). Two cabless boosters were also built, both for the New York Central (#3210–3211).
- Pinkepank, Jerry A. (1973). The Second Diesel Spotter's Guide. Milwaukee, WI: Kalmbach Publishing Co. pp. 310–314. ISBN 0-89024-026-4.