#3753
ALCO Century 855
🇺🇸 United States ·built by American Locomotive Company· from 1964· model of 3 (2 ‘A’ and 1 ‘B’) American twin-engined diesel locomotives
what is it?
The ALCO Century 855 was a model of 5,500 hp (4,101 kW) diesel-electric locomotive built in 1964 by the American Locomotive Company for the Union Pacific. The locomotive was notable for being ALCO's most powerful diesel-electric locomotive and, at the time, the most powerful diesel locomotive ever built, being surpassed by the 6,600-horsepower (4,922-kilowatt) 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.
who runs it
base stats
Bars compare against all trains: 600 km/h (maglev), 1,700 seats; power, weight and number built on a log scale up to 20 MW, 1,000 t and 20,000 built.
fun facts
- First built 62 years ago, in 1964.
- 4.1 MW is about 48 family cars (~85 kW each) flat out.
- Weighs about as much as 42 African elephants (~6 t each).
- 26.2 m long: about 6 cars parked nose to tail.
- Served for 8 years (1964–1972).
diesel locomotive: A diesel engine on board drives the wheels, usually through a generator (diesel-electric).
spec sheet
- built
- 1964
- in service from
- 1964
- retired
- 1972
- status
- retired
- number built
- 2
- kind
- Diesel-electric
- traction
- diesel
- origin
- 🇺🇸 United States
- builders
- American Locomotive Company
- operators
- Union Pacific Railroad
- top speed
- —
- power
- 4.1 MW
- gauge
- 1,435 mm standard gauge
- wheel arrangement
- B+B-B+B
- length
- 26.2 m
- weight
- 250 t
From the Wikipedia infobox and Wikidata. Blank means the sources don't say.
Sources: Wikidata Q432666, Wikipedia: ALCO Century 855 (CC BY-SA 4.0).Updated 2026-10-25.