The ALCO DL420 was the prototype ALCO S-5 diesel-electric

switcher locomotive A switcher locomotive (American English), shunter locomotive (British English), station pilot (British English), or shifter locomotive (Pennsylvania Railroad terminology) is a locomotive used for maneuvering railway vehicles over short distanc ...

. It was built in August, 1951 using an early six-cylinder 251 engine rated at and RS-3 subassemblies in its construction. It rode on two-axle

trucks A truck or lorry is a motor vehicle designed to transport freight, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construction ...

with a B-B wheel arrangement, and was the first ALCO switcher with a front radiator opening. This one-of-a-kind unit spent its time at the

Niskayuna Niskayuna is a town in Schenectady County, New York, United States. The population was 23,278 at the 2020 census. The town is located in the southeast part of the county, east of the city of Schenectady, and is the easternmost town in the county. ...

test facility, then at Schenectady as a shop switcher (#6). It was scrapped in the late 1950s.

References

Data from The American Locomotive Company A Centennial Remembrance by Richard Steinbrenner pp. 311-312 photo, 340 photo, 394 photos

B-B locomotives DL420 Experimental locomotives Diesel–electric locomotives of the United States Railway locomotives introduced in 1951 Standard-gauge locomotives of the United States Scrapped locomotives Unique locomotives Individual locomotives of the United States Shunting locomotives {{diesel-loco-stub

See also

References