The Alco C420

One of the first of the American Locomotive Company's (Alco) new Century models was the C420. It was a four-axle design that offered sufficient horsepower. However, to some extent Alco continued to catalog custom models when a universal design would have sufficed, such as what EMD and General Electric had been doing for years (particularly the former). For instance, the C420 was meant to be a less powerful version of the C424, which was being produced at the same time. The Alco C420 had modest sales but the first design of the Century series did little to improve Alco's standing in the locomotive manufacturer's race. Interestingly, despite lukewarm sales numerous C420s are preserved today and several remain in operation on shortlines, nearly 50 years since the last was outshopped.

Delaware & Hudson C420s #405 and #407 along with a pair of RS11s and a GP39-2 head eastbound out of Buffalo, New York at William Street with train BM-4 on November 7, 1982.

The Alco C420 used the builder's new 261C prime mover that was much more reliable over its earlier designs. The model began production in June of 1963 and as was the case with late RS designs, the C420 featured a standard low nose (high nose units were only built on request, and some were built on the C420 model), similar to the Standard Cab design first employed by EMD on its GP30 model. As the designation suggests (which was a completely new system unveiled by Alco whereby the "C" stood for Century, "4" regarded the number of axles, and "20" referred to the horsepower), the C420 was capable of producing 2,000 horsepower and found buyers among a number of Class I railroads such as the Lehigh Valley, Norfolk & Western, Louisville & Nashville, and Monon. Interestingly, the largest buyer of C420s was the Pennsylvania-owned Long Island Rail Road, which owned thirty.

Once again, the C420 was more of a reactionary model released by Alco in an attempt to remain competitive with newcomer General Electric and its U25B released in 1959. It's rather unfortunate that by the early 1960s Alco was looked upon with resignation by the industry as the Century series, particularly the four axle models, were quite adept locomotives which were very reliable. Additionally, they continued to offer incredible pulling power (an Alco trademark) and fuel efficiency. Surprisingly, despite GE now being an Alco competitor, the Schenectady manufacturer continued to purchase from its one-time ally internal components as it always had such as traction motors and generators.

BC Rail C420 #631 and yard slug #S407 are seen here in North Vancouver, British Columbia on May 21, 1992.

From a technical standpoint the Alco C420 was meant to replaced the RS32 model and while it offered less starting tractive effort (57,200 pounds) provided more continuous effort (38,000 pounds). Interestingly, neither Alco nor GE sold many models during the mid-1960s as EMD was once again dominating the market with its 2,500 horsepower GP35 of 1963 (which would go on to sell well over 1,000 examples).  By the time production had ended in 1968 only a little over 100 Alco C420s had been built. However, aside from the large Class Is who purchased the model several smaller lines did as well such as the Piedmont & Northern, Tennessee Central, Lehigh & Hudson River, Erie Mining, Mississippi Export, and even the Secratario de Communicaciones Y Transportes of Mexico.

Alco C420 Production Roster

Owner Road Number(s) Quantity Date Built
Erie Mining600-60231965
Lehigh & Hudson River21-2991963-1966
Lehigh Valley404-415121964
Long Island Rail Road200-229301963-1968
Louisville & Nashville1300-1315161964-1966
Mississippi Export6311965
Monon501-518181966-1967
Nickel Plate Road57811964
Norfolk & Western413-42081964
Piedmont & Northern2000-200121965
Seaboard Air Line110-136271965
Secratario de Communicaciones Y Transportes7123-10, 7123-1121965
Tennessee Central400-40121966


Norfolk & Western C420 #417 is seen here in Brewster, Ohio on June 24, 1975. The N&W tried out several of Alco's diesel models but ultimately only purchased eight of its own C420s new in 1964, #413-420.

Perhaps most fascinating with this model, in terms of its history, is how many continued to find usefulness in freight service long after they were sold by their original owner. Today, close to 40 of this relics remain preserved with the most famous in operation on the Apache Railway.  Unfortunately, those in operation on short line Arkansas & Missouri (the fabled Alco line) have an uncertain future after the railroad announced in July it was acquiring three new EMD SD70ACes and would retiring much of its Alco fleet.  For more information about the C420 regarding a complete production roster please refer to the chart above.

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A History Of The American Locomotive Company (Alco)




A History Of The Montreal Locomotive Works (MLW)


Other Alco Century Models



The C415




The C424




The C425




The C430




The C628




The C630




The C636




The C643DH (Experimental)




The C855 (Experimental)


Alco's Notable Prime Movers



The Model 244




The Model 251