Great Northern boxcab (3 phase)
The GN boxcab locomotives were the first electric locomotives purchased by the Great Northern Railway for use through the Cascade Tunnel. Four locomotives were supplied by the American Locomotive Company; they used electrical equipment from General Electric and weighed each..
They were three-phase electric locomotives producing each. The specification called for 1000hp, but the actual output was substantially greater, as described by the consultant engineer Cary T. Hutchinson. They had a B-B wheel arrangement. They were built in February and March 1909, and delivered in Pullman Green. The GN numbered them 5000–5003 and they were used until May 1927.
Initially three locomotives were coupled together and hauled trains at a constant speed of, but when larger trains required four locomotives the motors were concatenated, so that the speed was halved to to avoid overloading the power supply.
