The Soo Line at Ladysmith, Wisconsin

The text of the sign, "SWEET 'Soo'", follows:

Locomotive 500-A, nicknamed Sweet 'Soo', was the first passenger diesel on the Minneapolis, St. Paul and Sault Ste. Marie Railway ("Soo Line"). The 1,500 h.p. FP7 heavy passenger engine was built in November of 1949 by the Electro-Motive Division of General Motors as a demonstrator. It was acquired by the Soo Line in the spring of 1950 along with a cabless F7 booster. Numbered 500-A and 500-B, they were repainted in the Soo Lines maroon and gold color scheme. Before 1950 all Soo Line passenger trains were powered by steam locomotives. The 500-A and -B were the first Soo Line diesel-electric locomotives in regular passenger service, pulling the "Soo-Dominion" on May 22, 1950. Steam power on the Soo Line ended in 1955. The 500-A pulled passenger trains until the mid-1960s when that era ended. It was in freight and later snow plowing service until 1985, when it was retired with over 1.5 million miles. This historic diesel, owned by the City of Ladysmith, has been restored to its 1950 appearance. The 250,000 pound locomotive is the only streamlined Soo Line F unit preserved in the State of Wisconsin. It is displayed with U.S. Rail Post Office-Railway Express Agency car 552, baggage-passenger car 358, and 1st Class coach 998 - all original Soo Line equipment.