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.[2] Despite its impressive power output, all three examples of the class were scrapped by early 1972 due to mechanical unreliability.
History
Powered by a pair of 16 cylinder
ALCO 251C diesel engines, and rated at 5,500 hp (4,101 kW), it was ALCO's answer to the
EMD DD35A and the
GE U50. 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 units and one
B unit were built, all for the
Union Pacific, which had also requested double-engined locomotives from
EMD and
GE in order to replace the turbines, which had become uneconomical to operate.[1]
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; 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.[3]
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.[2] Despite its impressive power output, all three examples of the class were scrapped by early 1972 due to mechanical unreliability.
History
Powered by a pair of 16 cylinder
ALCO 251C diesel engines, and rated at 5,500 hp (4,101 kW), it was ALCO's answer to the
EMD DD35A and the
GE U50. 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 units and one
B unit were built, all for the
Union Pacific, which had also requested double-engined locomotives from
EMD and
GE in order to replace the turbines, which had become uneconomical to operate.[1]
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; 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.[3]