The ALCO Century 855 was a model of diesel-electric locomotive built in 1964 by the

American Locomotive Company The American Locomotive Company (often shortened to ALCO, ALCo or Alco) was an American manufacturer of locomotives, diesel generators, steel, and tanks that operated from 1901 to 1969. The company was formed by the merger of seven smaller locomo ...

for the Union Pacific Railroad. The locomotive was notable for being ALCO's most powerful diesel-electric locomotive and, at the time, the most powerful diesel locomotive ever built,"6,000 HP Diesel-Electric for Fast Freight Traffic in USA" ''

Railway Gazette ''Railway Gazette International'' is a monthly business magazine and news website covering the railway, metro, light rail and tram industries worldwide. Available by annual subscription, the magazine is read in over 140 countries by transport ...

'' July 3, 1964 pages 547-550 being surpassed by the EMD DDA40X in April 1969. The Century 855 was designed and built specifically for Union Pacific, which was in need of very high horsepower locomotives for its Overland Route through the Rocky Mountains. Despite its impressive power output, all three examples of the class were scrapped by early 1972 due to mechanical unreliability.

History

GE U50 The GE U50 was an eight-axle, diesel-electric locomotive built by GE Rail. They were twin-engined locomotives, combining two diesel engines. Configuration The U50 rode on four two-axle trucks, grouped in pairs linked by span bolsters, giving ...

. The C855 rode on four two-axle trucks, grouped in pairs linked by span bolsters, giving a wheel arrangement of B+B-B+B. The trucks and bolsters were similar to those under UP's earlier turbine locomotives. Only two

A unit A, or a, is the first letter and the first vowel of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''a'' (pronounced ), plural ''aes'' ...

s and one

B unit B, or b, is the second letter of the Latin-script alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is '' bee'' (pronounced ), plural ''bees''. It re ...

were built, all for the Union Pacific Railroad, which had also requested double-engined locomotives from EMD and GE in order to replace the turbines, which had become uneconomical to operate. Union Pacific also wished to reduce the number of locomotives needed on a consist, to keep in line with their allowable gross weight limit. By consolidating several locomotives into one or two, this allowed them to lower the axle load on the rails, but to stay within the limits placed by the company. They spent their lives in the general freight pool at

North Platte North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating direction or geography. Etymology The word ''north'' is ...

; however, constant shutting down due to overheating & poor performance with its twin prime movers led to their early retirement and eventual scrapping by February 1972, after only being in service for less than eight years.

References

{{ALCO diesels Century 855 Diesel-electric locomotives of the United States B+B-B+B locomotives Union Pacific Railroad locomotives Railway locomotives introduced in 1964 Locomotives with cabless variants Scrapped locomotives Freight locomotives Standard gauge locomotives of the United States (Bo'Bo')(Bo'Bo') locomotives

History

See also

References