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 classificati