Baldwin VO-660, Class BS6

The Baldwin VO-660 was a diesel-electric locomotive switcher built by Baldwin Locomotive Works between April, 1939 and May, 1946. The 197,520–203,980 lb units were powered by a six-cylinder diesel engine rated at 660 horsepower, and rode on two-axle AAR Type-A switcher trucks in a B-B wheel arrangement. 142 examples of this model were built for American railroads, along with the United States Navy. Baldwin replaced the VO-660 with the model DS-4-4-660 in 1946.

Baldwin VO-1000, Class BS10

The Baldwin VO-1000 was a diesel-electric locomotive (switcher) built by Baldwin Locomotive Works between January 1939 and December 1946. The 236,260–242,200 lb units were powered by a normally aspirated eight-cylinder diesel engine rated at 1,000 horsepower, and rode on a pair of two-axle trucks in a B-B wheel arrangement. These were either the AAR Type-A switcher trucks, or the Batz truck originally developed by the Atchison, Topeka and Santa Fe Railway as a leading truck for steam locomotives. 548 examples of this model were built for American railroads, including examples for the Army and Navy.

Baldwin DS-4-4-660, Class BS6a

The Baldwin DS-4-4-660 was a four-axle 660 horsepower diesel-electric switcher built by the Baldwin Locomotive Works at it Eddystone, Pennsylvania factory between 1946 and 1949. It replaced the 660 horsepower VO-660 in their catalog, and was in turn replaced by the 750 horsepower DS-4-4-750. It was the low power companion to Baldwin's DS-4-4-1000 models.

Baldwin DS-4-4-1000, Class BS10a / BS10am

The Baldwin DS-4-4-1000 were two models of four-axle 1,000 horsepower diesel-electric switching locomotives built by the Baldwin Locomotive Works between 1946 and 1951. The first models (56 locomotives) was powered by an 8-cylinder normally aspirated prime mover, but from 1948, a change was made to the second model powered by a 6-cylinder turbocharged engine. These two models replaced the VO-1000 in Baldwin's catalogue, and were in turn replaced by the S-12 in 1951.

Baldwin DS-4-4-750 / S-8, Class BS7 / BS7m

The Baldwin DS-4-4-750 was a four-axle 750 horsepower diesel-electric switcher built by the Baldwin Locomotive Works at it Eddystone, Pennsylvania factory between 1949 and 1951. It was a bridge between the 660 horsepower DS-4-4-660 and the S-8. It was the low power companion in Baldwin's catalog to their DS-4-4-1000 and the S-12.

The Baldwin S-8 was an 800-horsepower diesel-electric locomotive intended for use in yard switching. The Baldwin Locomotive Works produced a total of 63 units (61 for United States railroads and 2 for use in Cuba) between 1951 and 1953. 

Baldwin DRS-4-4-1000, Class BS10as

The Baldwin DRS-4-4-1000 was a diesel-electric road switcher produced by the Baldwin Locomotive Works from July, 1948–March, 1950. The units featured a 1,000 horsepower, six-cylinder prime mover, and were configured in a B-B wheel arrangement mounted atop a pair of two-axle AAR Type-B road trucks, with all axles powered. They had a cast steel frame. The units were configured to normally run with the long hood in the forward position.

Only 9 were built for American railroads, with another 13 manufactured in January and February, 1949 by the Canadian Locomotive Company for the Esquimalt and Nanaimo Railway, the first railroad in Canada to dieselize its locomotive fleet. The DRS-4-4-1000 was (in most cases) visually indistinguishable from its 1,200 horsepower (890 kW) successor, the Baldwin RS-12.

Baldwin S-12, Class BS12 / BS12m

The Baldwin S-12 was a 1,200-horsepower diesel-electric locomotive intended for use in yard switching. Utilizing a turbocharged 6-cylinder version of the powerful 606A diesel prime mover, S-12s were known for their "lugging" power, despite being temperamental. Like most Baldwin switchers, the S-12 had AAR Type-A switcher trucks in a B-B wheel arrangement. 451 units were built between 1951 and 1956, when Baldwin left the locomotive market.

Baldwin RS-12, Class BS12am / BS12ams / BS12as

The Baldwin RS-12 railroad locomotive was a 1,200 hp diesel-electric road-switcher configured with an AAR type B-B wheel arrangement. It was the follow-on model to the 1,000 hp DRS-4-4-1000, first introduced in 1948. It was more successful than its predecessor selling 50 units to eight railroads, versus 22 units to three railroads. Only one railroad, The Pennsylvania Railroad bought both models.

When Baldwin Locomotive Works merged with Lima-Hamilton the combination Baldwin-Lima-Hamilton decided to concentrate locomotive production at Baldwin's Eddystone, Pennsylvania plant. 

The locomotive could be ordered with either a steam generator for steam heat, or dynamic brakes contained within the short hood.

Baldwin AS-616, Class BS16m / BS16ms

The Baldwin AS-616 (or as the locomotive is sometimes incorrectly known, the Baldwin DRS-6-6-1600) was a diesel-electric locomotive of the road switcher type rated at 1,600 horsepower, that rode on three-axle trucks, having a C-C wheel arrangement. Nineteen railroads bought 214 locomotives, and two railroads bought seven cabless B units. The AS-616 was valued for its extremely high tractive effort, far more than any ALCo or EMD product. It was used in much the same manner as its four-axle counterpart, the Baldwin AS-16, and its six-axle sister, the Baldwin AS-416, though the six- traction motor design allowed better tractive effort at lower speeds.