Built by the General Motors Electromotive Division as a replacement of the SW1200, the SW1500 was intended for switching duties, and was capable of light branch line work as a road switcher. It was a development of the SW1200 and previous SW-series switchers dating back many years earlier, and was fitted with a 1500 horsepower two-stroke V-12 diesel engine. A total of 808 examples were built from 1966 to 1974, serving industrial and railroad operators across the length and breadth of the United States, with approximately a quarter of the whole production initially purchased by the Southern Pacific Railroad. A huge number of SW1500s can still be found in use today, proving the durability and versatility of this old locomotive design. The BNSF, Frisco and BN marks are licensed marks owned by BNSF Railway Company. CN is an exclusive copyright and mark of Canadian National Railway Company. All rights reserved. Used with permission. NS and Southern are registered and/or common law marks of Norfolk Southern Corp. All rights reserved. Used with permission. Southern Pacific, Western Pacific and the Union Pacific shield are registered trademarks used under license.