switcher stack, while early units were generally modified with taller stacks too. Early locomotives had a single large headlight, while later had twin sealed-beam headlights. Original owners There were 7 units built as EMD demonstrators: #152 (to Scullin Steel #6), 700 (to Manufacturers' Junction Railway #7), 755 (to Inland Steel #51), 804 (to Southern Pacific Railroad #1000, pictured above), 905 (to Central of Georgia #1), 906 (to Western Pacific Railroad #501), 911 (to Great Lakes Steel #11) Owego and Harford Railway was still operating one SW1 for switching duties in their yard as of 2010, sitting derelict in a railyard in Owego, NY, as of 2019 As of 2013, Amtrak still has one SW1 on their roster. #737 is used for switching chores at the Wilmington Delaware shops. As of 2021, Metra commuter rail rosters one SW1. It is used for Yard Service and power on work trains on the Metra Electric and Rock Island lines. It was originally built in 1945 for the Rock Island. Metra used to operate a second SW1, built in 1939, but sold it in June 2021 via online auction for $45,000 due to an internal engine failure. The unit built in 1939 was rumored to be one of the oldest operating diesels in Illinois and the oldest operating locomotive in the U.S. that was not preserved. Preservation Andersen Windowalls 3110 is preserved in operational condition at the Minnesota Transportation Museum. It was previously Norfolk and Western Railway 3110 and originally Wabash Railroad 110, built in June 1949. Arkansas–Oklahoma Railroad 536 is in operational condition and in regular freight service. It was previously Chicago, Rock Island and Pacific 536 and is painted in a Rock Island inspired paint scheme. Baltimore and Ohio 8408 is preserved at the Wilmington and Western Railroad in operational condition. Billings Grain Terminal 84, built as Chicago, Burlington and Quincy 9139 in 1939, was purchased by railroad operator and leasing firm St Johns River Companies in 2022 with the goal of restoring the locomotive into operating condition. After the formation of the Burlington Northern in 1970, 9139 was renumbered to 84, where it served for 5 years before being sold to the Davenport, Rock Island and Northwestern. In 1984, the locomotive was sold to a grain elevator in Billings, MT where it remains today. Black River and Western Railroad Lehigh Valley 112, is preserved on the BR&W in operational condition. And