The Baldwin S-12

The Baldwin S-12 was an upgraded version of its predecessor, the S-8 although both models were cataloged at the same time. Similar in size and mechanics, save for increased horsepower, this final switcher model manufactured during the 1950s sold relatively well for the company as numerous railroads and private industries purchased the model. While the locomotive did have some complaints regarding reliability it was revered for its ability to out-pull nearly anything in its class (a Baldwin trademark). The S-12 also saw the builder do away with the earlier complicated classification system and introducing one much simpler. Today, the S-12 remains one of Baldwin's best preserved diesels with at least fifteen still known to exist; seven at museums or tourist lines and eight more owned by short line SMS Lines.

Milwaukee Road S12 #909 is seen here in Hastings, Minnesota on June 24, 1964.

The Baldwin S-12 switcher began production in 1951 and by that time was technically a product of the Baldwin-Lima-Hamilton Corporation (BLH). BLH was formed through the merger of the Baldwin Locomotive Works and Lima-Hamilton in 1951 after the former came under the control of Westinghouse Electric Company, a long time supplier of internal components for Baldwin's diesels (the two companies had also collaborated on several electric locomotives dating back to the 19th century).  Thanks to the S-12's increased horsepower it sold much better than its less powerful counterpart. 

Other Baldwin Switcher Models

Baldwin's First Model, The Modestly Successful VO-660 

The Company's Bestselling Diesel Model, The VO-1000

The Modestly Successful DS-4-4-660 

The 750 Horsepower DS-4-4-750 

Last Of The "DS" Line, The Popular DS-4-4-1000 

A New Generation Of Switcher, The S-8 

The Unique Transfer Model, The DT-6-6-2000 

Baldwin's Late-Era Transfer Design, The Unsuccessful RT624 

For more information about the S-12 model please click here.  At 1,200 horsepower using Baldwin's latest prime mover, the 606A SC railroads found the locomotive quite versatile in several applications from yard and industrial work to revenue service on secondary and branch lines.  The locomotive came equipped with standard four axle (B-B) trucks and could produce a hefty 72,000 pounds of starting tractive effort (34,000 pounds continuous).  When production had ended in August, 1956 the model had been sold to several railroads like the Chicago & North Western, Jersey Central, Southern Pacific, New York Central, Southern, and the ever-loyal Pennsylvania. Additionally the military and industries purchased the locomotive including the Army, U.S. Steel, Armco Steel, American Smeting and Refining Company, Erie Mining, and others. In total, Baldwin sold 451 examples of the S-12.

Great Northern S12 #24 works the Minneapolis yard on June 14, 1964.

The S-12 was certainly Baldwin's most popular switcher in terms of its horsepower rating and general reliability. This is a significant reason why the model continues to find use in short line service today, notably on shortline SMS Lines which owns eight; their heritage includes Michigan Limestone #116, Tennessee Valley Authority #200, U.S. Navy #65-00372, demonstrator #1200, SP #1547, Erie Mining #7241, Monongahela Railway #425, and Great Northern #27. While four of these locomotives are operational, four are also used as a parts source.  Additionally, seven others can be found at museums; Patapsco & Back Rivers #345-#346, Erie Mining #403, NYC #9313, SP #1550, Texas & New Orleans (SP) #121, and Oliver Iron Mining #933.   Finally, for more information about the S-12s and all Baldwin switcher models please refer to the chart below.   

Baldwin S-12 Production Roster

Owner Road Number(s) Quantity Date Built
Akron & Barberton Belt Railroad27-2821951-1952
American Smelting & Refining Company1954-195521952
Apache Railway60011952
Armco Steel Corporation70611955
Atlanta & West Point67811951
Baldwin (Demo)1200-1201, 463-46771953
Calumet & Hecla Railroad20311951
Central of Georgia311-31441953
Central Railroad Of New Jersey (CNJ)1053-105971951
Chicago & North Western1073-1076, 1106-1109, 1117-1121, 1126-1128151951- 1954
Columbia-Geneva Steel Division (U.S. Steel)33-3531956
Erie Railroad617-628121951-1952
Erie Mining400-40341955-1956
Fairless Works (U.S. Steel)GE-1 - GE-8, GE-17, GE-18101951-1952
Great Northern24-2851953
International-Great Northern Railroad (MP)9230-923231952
Kansas City Southern1160-116341951
Lehigh Valley230-243141950
McCloud River Railroad30-3121953
Michicgan Limestone & Chemical Company116-11721953
Milwaukee Road1905-1925211950-1954
Missouri-Kansas-Texas Railroad (Katy)1201-1215151951-1952
Missouri Pacific9200-9226271951-1952
Monongahela Railway400-426271953-1954
New Orleans Public Belt61-6221955
New York Central9308-9328211951-1952
Oliver Iron Mining Company93311951
Patapsco & Back Rivers Railroad335, 345-34741951-1953
Pennsylvania8100-8104, 8732-8796, 8976-8993881951-1954
Pennsylvania-Reading Seashore Lines (PRSL)6017-6021, 6028-6033111953- 1956
Rayonier, Inc.201-20221956
St. Louis, Brownsville & Mexico Railroad (MP)9227-922931952
Seaboard Air Line1462-1465, 1476-1481101952-1953
Sharon Steel Corporation1, 1021951
Sierra Railroad40, 4221955
Soo Line313-31421952
Southern Pacific1442-1463, 1492-1513, 1539-1550561951-1953
Southern Railway2290-2299101952
Tennessee Coal & Iron Railroad1200-120781950-1951
Tennessee Valley Authority1-3, 20041952-1954
Terminal Railroad Association Of St. Louis (TRRA)1250-125341952
Texas & New Olreans (SP)105-10731952
Union Terminal Railway Of Memphis (MP)9233-923971953
U.S. Air Force1841-184221952
U.S. Navy65-00292, 65-00293, 65-00315, 65-00365 - 650074, 65-00391141951- 1953
Wabash Railroad305-309101952-1953

Lehigh Valley S12 #232 runs light through Wilkes-Barre, Pennsylvania on June 12, 1972.

For more information on Baldwin locomotives the book by the same name, a Brian Solomon title, provides an in-depth history of the company from its earliest days beginning in the 1930s to its final years constructing diesels during the mid-20th century.  It 160 pages in length and, as with every Solomon book, offers a rich collection of large, sharp photos to enjoy.  Another title of interest is Vintage Diesel Locomotives by noted author and historian Mike Schafer.  This one has been out for several years now and is a paperback title but highlights several classic models from the major builders of the era such as Electro-Motive, Baldwin, and the American Locomotive Company.

Top Of Page

› S-12

A History Of The Lima Locomotive Works

A History Of The Whitcomb Locomotive Works

A History Of The Baldwin Locomotive Works