Baldwin "DS-4-4-660" Locomotives

The Baldwin DS-4-4-660 was meant to replace the company's earlier VO660 design. The two models were very similar offering the same horsepower and wheel arrangement with the biggest difference being the prime mover, which was changed in the DS-4-4-660. Interestingly, while the Baldwin Locomotive Works' own prime mover proved to be a troublesome design in its larger road switchers and main line diesel locomotives the engine actually worked quite well in its small switchers, like the DS-4-4-660 and DS-4-4-1000. The company built three switchers with its own prime mover, including the DS-4-4-750 although this last model was not nearly as successful as its predecessors. As you can also see Baldwin changed its model designations when it began using its own diesel engine, which will be explained in more detail below. 

Today, at least three DS-4-4-660s are known to be preserved; Morrisey Femie & Michel #1 at the Western Pacific Railroad Museum, Sloss-Sheffield Steel #30 at the Sloss Furnace Museum, and Chesapeake Western #662 at the Virginia Museum of Transportation.

Penn Central DS-4-4-660 #7862, still wearing its Pennsylvania heritage, is tied down at Little Creek, Virginia on September 20, 1969. This was the furthest south the PRR network reached. Roger Puta photo.

The Baldwin DS-4-4-660 debuted in 1946, right after the builder canceled its VO660 line. Using a model 606 NA prime mover developed specifically by Baldwin (although the engine could not have been built without the help of subsidiary the I.P. Morris & De La Vergne company purchased in 1931) the DS-4-4-660 featured the standard four-axle, B-B truck setup. As with almost all of its diesel models, Baldwin contracted with Westinghouse to supply it for the locomotives' internal components such as traction motors, generators and air equipment (brakes and compressors). Additionally, the DS-4-4-660 offered tractive effort ratings virtually the same to the earlier VO660; 49,625 pounds starting and 34,000 pounds continuous.

After Baldwin began manufacturing its own prime mover it reclassified its diesel models according to their type (such as road switcher, switcher, transfer, etc.) total axles, powered axles, and finally horsepower. So, in the case of the DS-4-4-660 model the DR referred to Diesel Road 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 660 stood for the horsepower rating. As the company began to release future designs they shortened the classification system although because they also changed the designation for the same model-type it made things even more confusing. For instance, in the case of the road switcher they used terms such as "DR", "DRS", and "RF".

A Baldwin company photo of new Erie DS-4-4-660 #383 circa 1946.

Once again this "updated" version of the original VO660 sold relatively well, at least for a Baldwin product, with railroads as more than 130 were built through May of 1949. Overall, one could find Baldwin DS-4-4-660s around the country operating on a number of Class I railroads from the Pennsylvania and [original] Norfolk Southern in the east to the Wabash and Chicago & North Western in the Midwest. The model would probably have sold better but with Baldwin already offering the more powerful DS-4-4-1000 design most railroads preferred it instead.  

Baldwin DS-4-4-660 Production Roster

Owner Road Number(s) Quantity Date Built
American Cyanamid Company1311946
Armco Steel Corporation100111946
Chesapeake Western Railway661-66331946
Chicago & North Western1259-126131949
Chicago, St. Paul, Minneapolis & Omaha (C&NW)7111949
Erie Railroad381-38551946-1949
Escanaba & Lake Superior10111947
Georgia Northern Railway102112/1947
Long Island Rail Road409-41241948
Morrissey, Fernie & Michel Railway111946
New Orleans Public Belt44-4961946-1949
Norfolk Southern (Original)661-66331947
Patapsco & Back Rivers Railroad306-30941946
Pennsylvania5957-5966, 9000-9049, 9110-9121, 9210-9236991948-1949
Sloss-Sheffield Steel & Iron Company3011948
Tennessee Valley Authority10011949
Wabash Railroad201-20221947
Wyandotte Southern RailroadD-10011948
Wyandotte Terminal Railroad10411949


Chesapeake Western DS-4-4-660 #662, one of three the short line acquired new from Baldwin in 1946.

The quality Baldwin offered in its DS-4-4-660 helped it sell as many units as it did, along with its ability to pull just about anything. At 46 feet in length, the same size as its earlier counterpart, also made it an attractive locomotive for industries with companies like Armco Steel, American Cyanamid, Morrissy Fernie & Michel, and others purchasing at least one. Production on the locomotive ended in May, 1949 as the model was replaced by the slightly more powerful DS-4-4-750.  For more information about the DS-4-4-660 please refer to the chart above, which offers a complete production roster of the model.




  1. Home
  2.  ›
  3. Diesel Locomotives
  4.  ›
  5. DS-4-4-660

Header Photo: Drew Jacksich




Researching Rights-Of-Way

A popular pastime for many is studying and/or exploring abandoned rights-of-way.  Today, there are tens of thousands of miles scattered throughout the country.  Many were pulled up in the 1970's and 1980's although others were removed long before that.  If you are researching active or abandoned corridors you might want to check out the United States Geological Survey's (USGS) Historical Topographic Map Explorer.  It is an excellent resource with thousands of historic maps on file throughout the country.  Just type in a town or city and click on the timeline of maps at the bottom of the page!



Studying Diesels

You will be hard pressed at finding a better online resource regarding diesel locomotives than Craig Rutherford's TheDieselShop.us.  The website contains everything from historic (fallen flags) to contemporary (Class I's, regionals, short lines, and even some museums/tourist lines) rosters, locomotive production information, technical data, all notable models cataloged by the five major builders (American Locomotive, Electro-Motive, General Electric, Fairbanks-Morse, and Baldwin), and much more.  A highly recommended database!



Electro-Motive Database

In 1998 a gentleman by the name of Andre Kristopans put together a web page highlighting virtually every unit every out-shopped by General Motors' Electro-Motive Division.  Alas, in 2013 the site closed by thankfully Don Strack rescued the data and transferred it over to his UtahRails.net site (another fine resource).  If you are researching anything EMD related please visit this page first.  The information includes original numbers, serials, and order numbers.





A History Of The Lima Locomotive Works




A History Of The Whitcomb Locomotive Works




A History Of The Baldwin Locomotive Works