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Baldwin's "DS-4-4-1000": An Early, 1000 HP Switcher

Last revised: August 26, 2024

By: Adam Burns

The DS-4-4-1000, was Baldwin's first classified diesel switcher utilizing its own prime mover.  The variant replaced the builder's earlier VO-1000.

Interestingly, Baldwin's more powerful designs sold relatively well while smaller switchers like the DS-4-4-600, VO-660, and DS-4-4-750 were not nearly as popular with railroads.

As it turns out, the industry came to love a switcher ranging from 1,000-1,200 horsepower.  This seemed to be the ideal power setting for switching, branch line, and industrial applications.

Like rival American Locomotive, Baldwin struggled to produce a rugged and reliable road-switcher due to reliability issues. It was here where manufacturers made their money, locomotives aimed at daily freight service.  

The rigors required to produce such a machine were significant and only Electro-Motive proved very successful at such. 

In later years General Electric would as well.  In the end, the mighty Baldwin Locomotive Works, a bastion of the railroad industry since its inception, exited the locomotive market in the 1950's.

Photos

Penn Central DS-4-4-1000 #7960, a former PRR unit, was photographed here by Robert Eastwood, Jr. at Thorndale, Pennsylvania, circa 1969. American-Rails.com collection.

Overview

The DS-4-4-1000 followed its predecessor model, the VO-1000, in 1946 originally using the company's 608NA prime mover which could produce 1,000 horsepower using a B-B truck arrangement (two axles per truck).

Aside from the updated prime mover, the model was virtually identical to the VO1000 with all internal components outsourced to Westinghouse and continued to carry a length of 48 feet.

The builder produced variants with two different prime movers; the 608NA (Normally Aspirated and later 606SC (Supercharged).

Combined, the two were quite successful, selling more than 500 examples to numerous railroads and industries.  This time, Baldwin also found interest in Canadian lines, notably the Canadian Pacific Railway.

Once again, the company's best customer proved to be the Pennsylvania Railroad which bought 136 examples alone.

Milwaukee Road DS-4-4-1000 #947 is seen here between assignments at Winona, Minnesota in July, 1968. This unit was built as #1902 in October, 1949. Fred Byerly photo. American-Rails.com collection.

As with the DS-4-4-750, the DS-4-4-1000 ended Baldwin's use of its dizzying classification system.  In its place, the builder introduced a more standardized classification after 1951.

For instance, the S-8 and S-12 models, which replaced the DS-4-4-750 and DS-4-4-1000, used the "S" to signify they were switchers and the numbers designated their horsepower rating, abbreviated. 

Data Sheet and Specifications

Baldwin's 600 series diesel engines used in the DS-4-4-1000 locomotives were broken down as follows:

608NA Prime Mover

• 60 = 600 Series

• 8 = 8 Cylinders

• NA = Normally Aspirated

606SC Prime Mover

• SC = Supercharged

Prime Movers

608NA

606SC

Production Rosters

Total Built = 502

608NA

606SC

Sources

• Foster, Gerald. A Field Guide To Trains. New York: Houghton Mifflin, 1996.

• Kirkland, John F. Diesel Builders, The:  Volume Three, Baldwin Locomotive Works. Pasadena: Interurban Press, 1994.

• Pinkepank, Jerry A. Diesel Spotter's Guide.  Milwaukee: Kalmbach Publishing Company, 1967.

• Solomon, Brian.  Baldwin Locomotives.  Minneapolis:  Voyageur Press, 2009.

Because so many DS-4-4-1000s were built, a handful are preserved including:

• Santa Fe #2260


• Canadian Pacific #7069


• Missouri-Kansas-Texas #106


• Oakland Terminal #101


•  Reading #702

Additionally, short line SMS Lines, which fleets a large collection of Baldwins preferring their incredible ability to pull operations former Copper Range #101 and PRR #9069.