Green Mountain 405 (green, yellow) N Scale Alco RS1Details: The RS 1 was introduced by ALCO in March of 1941 with the delivery of the first of two units to the Rock Island. Combining the accessibility of a switching locomotive and the higher speed tracking of a road unit, the RS 1 started a revolution in locomotive design that was soon embraced by all of the major diesel electric builders. Despite ALCO's own introduction of higher horsepower roadswitchers, the 1,000 h. p. RS 1 had a production span of