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The Alco RS27

(Please note that the Alco models featured on this page are not Alco RS27s.)

The Alco RS27 was a late model of the Road Switcher (RS) series that produced more than 2,000 horsepower. However, the model was unsuccessful along with the fact that by the time it was debuted the American Locomotive Company (Alco) was already working on its next generation of road switcher, the Century series. As such, the RS27 looked very much like Alco's later models and was the first to receive the builder's new styling. By the late 1950s Alco was slipping further behind the Electro-Motive Division in the locomotive market and before the decade was over it would also be competing with one-time ally General Electric. Interestingly, examples of this rare Alco model can still be found, in service on shortline Minnesota Commercial (a haven for Alcos). The locomotives were purchased from the Green Bay & Western, which had purchased them from the Chicago & North Western (#901 and #903).

The Alco RS27 began production in 1959 using a B-B format (two axles per truck) and producing a hefty 2,400 horsepower for a somewhat small, four-axle unit. As with other late-model RS designs the RS27 came in a standard low-nose setup using Alco's much more reliable 251B prime mover. In terms of the company's history as a locomotive builder, the RS27 offered the first glimpse of its Century series, which began production in 1963. The model retained the flush, long hood with the cab and the classic notched corners on the carbody remained. However, the cab featured a slight design change with raised number boards and headlights, and the nose was shorter giving the locomotive a more blunted appearance.

From an exterior standpoint the RS27 began the common look of second-generation designs, as GE used a similar setup with its U25B, and EMD did the same beginning with its GP18, GP20,and GP30 models. Perhaps it was due to Alco's earlier troublesome engine designs that kept railroads away but whatever the case the builder found little success with the RS27 selling less than thirty units with the Pennsyvlania Railroad purchasing the most (15). The year 1959 was not a particularly good one for Alco. It was increasingly losing market share to EMD, had not cataloged a successful locomotive since the RS3 finished production in 1956 (although its RS11 design did sell relatively well), and that year GE ended its five decade partnership with the company when it released its own line of diesels beginning with the U25B (which ironically far outsold the RS27).

From an operational standpoint, the RS27 varied little from the RS11 aside from the additional horsepower. It actually offered less continuous tractive effort (42,000 pounds) but more starting effort (66,000 pounds). As had been the case for nearly two decades when the RS27 was produced, internal components like traction motors, generators, and air brakes/compressors came in from GE and Westinghouse. In the end, just four Class I railroads purchased the Alco RS27; the aforementioned PRR, Soo Line, Chicago & North Western, and Green Bay & Western. Of note, however, Union Pacific did purchase two of the demonstrators, #640-2 and #640-3. Somewhat unsatisfied, UP returned them to the Montreal Locomotive Works where they were later resold.

Today, the Minnesota Commercial is apparently quite happy with its two RS27s as the railroad has kept them in regular freight service for nearly three decades now. For a total production roster of Alco RS27s please click here. Also, if you would like to look over technical schematics and background on the model please click here. Finally, for more information about the RS27 and all RS series designs please refer to the chart below.

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RS Series

Model Type	Units Built	Date Built	Horsepower
RS-1	417	1941-1960	1,000
RSD-1	257	1942-1946	1,000
RS-2	469	1946-1950	1,500-1,600
RSC-2	81	1946-1950	1,500-1,600
RS-3	1,370	1950-1956	1,600
RSD-4	36	1951-1952	1,600
RSD-5	204	1952-1955	1,600
RSD-7	29	1954-1956	2,250-2,400
RS-11	426	1956-1964	1,800
RSD-12	161	1956-1963	1,800
RSD-15	87	1962-1960	2,400
RS-27	27	1959-1962	2,400
RS-32	35	1961-1962	2,000
RS-36	40	1962-1963	1,800

For a comprehensive look at the American Locomotive Company and all of the motive power types it built from steam, diesel, to electrics consider the book Alco Locomotives by Brian Solomon. Covering more than 175 pages Mr. Solomon's book details the history of Alco from its esteemed 4-6-4 Hudsons and 4-6-6-4 Challengers to vaunted RS and PA series diesel locomotives. If you have any interest in Alco this book is a must have!

Also consider Mike Schafer's Vintage Diesel Locomotives which looks at virtually all of the classic builders and models from Alco PAs to early EMD Geeps. If you’re interested in classic Alcos, or diesel locomotives in general, this book gives an excellent general history of both. If you're interested in perhaps purchasing either (or both) of these books please visit the links below which will take you to ordering information through Amazon.com, the trusted online shopping network.

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