Generating up to 3,200 continuous horsepower, #E-2 was used primarily to pull transcontinental passenger trains (including the famed Olympian Hiawatha) between Othello and Tacoma, WA, through the Cascade mountains. The 76-foot long electrically powered locomotive, weighing 260 tons, is the only survivor of five built for the Milwaukee Road. “Bi-polar” engines used a special motor to operate electrically. It was called a "bi-polar" design because of the two motor field magnet cores, one on each side of the motorized axles. Dual-facing engine.  They were designed to pull passenger cars.