|Massive example of a 1925 Alco-Schenectady oil burning locomotive built for the Southern Pacific. Specifics - class SP-1, 63.5" drivers, 225psi boilier pressure, 25x32" high pressure cylinders (2), 25x28" low pressure cylinders, engine weight 445,000 lb, tractive effort of 86,589 lb. Drury (1993) notes that they were too rigid for the curves snaking through the Donner Pass, where they were first tried. After relocation to the Sunset Route east of Los Angeles, the 4-10-2s ran until the mid-1950s. It is there - between Roseville and Summit, Calif on a 2 1/2%, 80-mile grade - "...the engines were remarkably successful because the operating condtions prevented excessive speeds and the even torque of the three cylinders prevented undue stalling at low speeds." No exact date, location or photographer was listed.