This three-quarters cutaway
view of a sixteen cylinder ALCO 251 engine was featured in the
manufacturers brochure for their Century Series diesel locomotives.
The marine version of the engine normally has a deeper oil pan.
Artwork produced by ALCO Products around 1964.
HISTORY OF THE ALCO 251
The American Locomotive Company
(ALCO) originated from the mergers of a number of steam locomotive
manufacturers, and by the early 1900s had developed into one of
the largest locomotive builders in the world. Their main factory
was located in Schenectady, New York and the company also maintained
offices in New York City.
ALCO's product line was much larger
than just locomotives, they were also a builder of industrial
products including pipe, heat exchangers, springs, and oil industry
supplies. By the late 1920s they were one of the leading builders
of diesel engines in the US, through the efforts of their subsidiary
McIntosh & Seymour, located in Auburn, New York. M&S built
large, slow speed Diesel engines in a variety of sizes, and also
built 12-1/2 inch bore by 13 inch stroke medium speed engines
for railroad and marine applications. They were a pioneer in the
turbocharging of Diesel engines, and by World War Two their engine
product line included six and eight cylinder engines in both turbocharged
and non-turbocharged variations, for marine, rail, and industrial
service. This product series included the high-base Model 538
engine (marine, stationary and locomotive), the low-base Model
539 engine (marine and locomotive), and the welded block Model
540 engine (US Navy and other marine applications), as well as
a variety of other Diesel engines both larger and smaller. An
ALCO Model 539 engine is shown in the advertisement below.
By the middle of the war, their
existing engine product line was overtaken in horsepower output
by several other builders, particularly Electro-Motive Division
of General Motors, and Fairbanks-Morse. This led ALCO into a development
program for higher RPM Diesel engines with 8 inch bore and 10
inch stroke. After several years of experimentation ALCO introduced
their Model 244 engine in early 1946. This engine was widely produced
in locomotive applications during the rush to Dieselize the railroads
after World War Two, but it proved troublesome in its early years,
and although ALCO solved the problems, they realized that a more
durable engine with higher horsepower potential was needed. The
Model 251 was introduced in 1951, and was a completely different
design from its predecessor.
Over the course of many years of
service in the marine, railroad, and industrial markets, the Model
251 proved to be a successful and durable engine. Although US
sales of the engine dropped off after ALCO's exit from the US
locomotive market and closing of the Schenectady plant in 1968,
the Model 251 remained popular with overseas customers, particularly
in Asia and South America. The Model 251 new engine production
and replacement parts business was subsequently acquired by Bombardier
and then GE, before being sold to Fairbanks-Morse, who presently
continues to build the engine.
Although many of the locomotives
that originally used the Model 251 have reached the end of their
economical service lives and have been scrapped, the removed engines
often find a useful second life in the marine and industrial markets.
Replacement parts for the engines are still being manufactured
by Fairbanks-Morse, insuring that some of the remaining fleet
of Model 251 engines will continue to operate for many years in
to the future. The nearly six decade long production run of this
engine is impressive, but falls short of the Fairbanks-Morse OP
engine, which passed its 70th year of production in 2008.
Article and page design by Preston Cook, ©2009