Next year, the Essex Terminal Railway Co. (ETR) will mark its 120th anniversary. One of Canada’s oldest railroads, the short line was incorporated in 1902. But ETR is marking the occasion ahead of time with a commemorative SW1200, its longest-serving locomotive. The switcher recently was overhauled and repainted with the heritage green and yellow colors it sported in 1956, when the unit was manufactured by General Motors Corp.’s Electro-Motive Division.