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Baldwin "DRS-4-4-1500" Locomotives

Last revised: May 31, 2023

By: Adam Burns

Baldwin's DRS-4-4-1500 was the first in a road switcher series that bore long and confusing titles which the manufacturer produced over a nine-year period. 

Built in the late 1940s, the DRS-4-4-1500 found few buyers.   The locomotive carried similar lines to Alco's early road-switchers with the cab offset over a long hood with a short, trailing hood. 

To its credit, Baldwin's road-switchers carried fine lines and a clean appearance. Featuring a short hood, off-center cab, and trailing long hood the DRS-4-4-1500 had the appearance of the now classic road switcher.

Interestingly, while Baldwin struggled to sell its early road switchers, later variants under its Standard Line, built during the early 1950s, enjoyed somewhat more success. 


Western Maryland DRS-4-4-1500 #170 at work in Hagerstown, Maryland on August 9, 1963. She was later scrapped in 1969. American-Rails.com collection.


Had the builder continued to refine its product, as management had wished, Baldwin may have continued building diesels until at least the second-generation era. 

Unfortunately, its parent (Westinghouse) elected to exit the locomotive just as it appeared Baldwin might be gaining traction.

The DRS-4-4-1500 began production in April of 1946 and competed against Alco's early road-switchers.  At the time, Electro-Motive had yet to enter the road-switcher market (its BL2 was not introduced until 1948).

Aesthetically, the locomotive had a pleasing carbody and offered crews good visibility. However, mechanically railroads found its supercharged model 608SC prime mover (capable of producing 1,500 horsepower) troublesome and difficult to maintain.

As was the case with all of Baldwin's models, Westinghouse provided all of its internal components like traction motors, generators, and air brakes/compressors.

The two companies had collaborated since the late 19th century and Westinghouse manufactured excellent equipment, particularly traction motors that were extremely rugged and  durable.

Baldwin became known for its ability to produce that could out-muscle the competition in a big way.  For unknown reasons it never offered dynamic brakes or Multiple Unit capability (MU'ing) as standard options (both were optionally available).

The former was an important safety feature, an additional type of braking via the traction motors (very handy on steep, mountainous grades) while the latter allowed numerous coupled locomotives to be directly controlled by the lead locomotive.


Both became key selling points and from an early date both Electro-Motive and American Locomotive included these features as standard on their models.  

By the time production had ended in April of 1950 (directly prior to the Standard line's release) just thirty-five DRS-4-4-1500s had been built purchased by the:

  • Erie Railroad

  • Lehigh Valley

  • Soo Line

  • New York Central

  • Northern Pacific

  • Pennsylvania-Reading Seashore Lines

  • Western Maryland

  • St. Louis Brownsville & Mexico (Missouri Pacific)

Additionally, the foreign Iron Mines Company of Venezuela bought three units. 

Data Sheet and Specifications

Entered Production6/25/1947 (Western Maryland #170*)
Years Produced6/25/1947 - 4/29/1950
Baldwin ClassDRS-4-4-1500/1 SC
Engine608SC, 6-Cylinder In-Line, Supercharged
Engine BuilderDe La Vergne
Carbody StylingBaldwin
Length (Between Coupler Pulling Faces)58'
Weight240,000 Lbs
Height (Top Of Rail To Top Of Cab)14'
Width10' 2"
Truck TypeGSC Swing Bolster
Truck Wheelbase9' 10"
Wheel Size42"
Traction Motors370F (4)**, Westinghouse
Traction Generator471A, Westinghouse
Auxiliary GeneratorYG42A, Westinghouse
Gear Ratio15:63 or 19:60
Tractive Effort Rating42,800 Lbs at 10.5 MPH (15:63) or 32,200 Lbs at 14.0 MPH (19:60)
Top Speed65 MPH (15:63) or 82 MPH (19:60)

*  Entered service on July 5, 1947.

** Pennsylvania-Reading Seashore Lines units were equipped with model 370G traction motors.

Production Roster

Total Built = 35

Owner Road Number Baldwin Serial Number Construction Number Completion Date
Iron Mines Of Venezuela - Bethlehem Steel117313810/10/1947
Iron Mines Of Venezuela - Bethlehem Steel22731397/6/1949
Iron Mines Of Venezuela - Bethlehem Steel33731403/9/1948
Western Maryland1704733997/5/1947
Minneapolis, St. Paul & Sault Ste Marie (Soo Line)36057349712/1/1947
Minneapolis, St. Paul & Sault Ste Marie (Soo Line)36167349812/18/1947
Minneapolis, St. Paul & Sault Ste Marie (Soo Line)36277349912/16/1947
Minneapolis, St. Paul & Sault Ste Marie (Soo Line)3638735001/8/1948
Minneapolis, St. Paul & Sault Ste Marie (Soo Line)3649735011/8/1948
Minneapolis, St. Paul & Sault Ste Marie (Soo Line)36510735021/5/1948
Minneapolis, St. Paul & Sault Ste Marie (Soo Line)36611735032/3/1948
Minneapolis, St. Paul & Sault Ste Marie (Soo Line)36712735042/4/1948
New York Central830013734797/5/1948
New York Central830114734807/5/1948
Western Maryland17115736437/8/1948
Western Maryland17216736447/7/1948
Northern Pacific17517736459/22/1948
Northern Pacific17618736469/23/1948
St. Louis, Brownsville & Mexico (Missouri Pacific)411219736472/25/1948
St. Louis, Brownsville & Mexico (Missouri Pacific)411320736482/25/1948
St. Louis, Brownsville & Mexico (Missouri Pacific)411421736493/10/1948
St. Louis, Brownsville & Mexico (Missouri Pacific)411522736503/7/1948
Lehigh Valley200237365112/6/1948
Erie Railroad1100247365211/29/1949
Erie Railroad1101257428911/29/1949
Erie Railroad1102267429011/30/1949
Erie Railroad1103277429112/8/1949
Erie Railroad1104287429212/8/1949
Erie Railroad1105297429312/8/1949
Pennsylvania-Reading Seashore Lines600030747524/14/1950
Pennsylvania-Reading Seashore Lines600131747534/21/1950
Pennsylvania-Reading Seashore Lines600232747544/25/1950
Pennsylvania-Reading Seashore Lines600333747554/28/1950
Pennsylvania-Reading Seashore Lines600434747564/28/1950
Pennsylvania-Reading Seashore Lines600535747574/29/1950


  • 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.


The reasoning behind Baldwin's complicated classification is fairly straightforward. Because the company was so focused and dedicated to building steam locomotives it carried over a version of the classic Whyte notation (developed by Frederick Whyte to classify steam designs) and applied this to early diesel variants.

Using the DRS-4-4-1500 model as an example the DRS referred to Diesel Road Switcher unit; the first number, 4, was the designation of four overall axles; the second number, 4, was the designation of four powered traction motors; and 1500 stood for the horsepower rating.

By 1950, Baldwin would drop this difficult system with its new Standard Line, which simply referred to the motive power type and horsepower rating. 

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