| ALCO Century 420 | |
| Powertype: | Diesel-electric |
| Builder: | ALCO |
| Buildmodel: | Century 420 |
| Aarwheels: | B-B |
| Primemover: | ALCO 251 |
| Poweroutput: | 2000hp |
| Totalproduction: | 131 |
| Builddate: | June 1963 - August 1968 |
The ALCO Century 420 is a four-axle, 20000NaN0 diesel-electric locomotive. 131 were built between June 1963 and August 1968. Cataloged as a part of ALCO's "Century" line of locomotives, the C420 was intended to replace the earlier RS-32 model.
| Owner | Quantity | |
|---|---|---|
| Erie Mining | 3 | |
| Ferrocarril del Sureste | 2 | |
| Lehigh and Hudson River Railway | 9 | |
| Lehigh Valley Railroad | 12 | |
| Long Island Rail Road | 30 | |
| Louisville & Nashville Railroad | 16 | |
| Monon Railroad | 18 | |
| Mississippi Export Railroad | 1 | |
| New York, Chicago & St. Louis Railroad | 1 | |
| Norfolk & Western Railroad | 8 | |
| Piedmont and Northern Railway | 2 | |
| Seaboard Air Line Railroad | 27 | |
| Tennessee Central Railway | 2 | |
| Total | 131 |
Since 2005, roughly 30% of C420 production exists. All units ordered by Mississippi Export, New York, Chicago & St. Louis Railroad ("Nickel Plate"), and Piedmont & Northern Railway have been scrapped.
The two units delivered to the Piedmont & Northern were the first of the Phase II units.