Three rail operation, O gauge Williams NW2 in Monon livery. In 1939, GM's EMD division introduced two switcher locomotives, the NW-2 and its smaller sibling the SW-1. The NW-2 was equipped with a 1000 H.P. twelve cylinder engine. It was GM's most popular switcher of all time, with over 1100 units sold. The last unit was manufactured in December of 1949. Many railroads and shortlines have rebuilt these units due to their flexibility and reliability.
