Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The ALCO Century 420 was a four-axle, 2000 horsepower diesel locomotive of the road switcher type. 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. Since 2005, roughly 30% of C420 production exists. All units ordered by Mississippi State Export, New York, Chicago & St. Louis Railroad, and Piedmont & Northern Railway have been scrapped.