Great Northern boxcab (3 phase)

The GN boxcab locomotives were the first electric locomotives purchased by the Great Northern Railway (GN) for use through the Cascade Tunnel. Four locomotives were supplied were built in February and March 1909 by the American Locomotive Company, and delivered in Pullman Green; they used electrical equipment from General Electric and weighed 115 ST each.

They were three-phase electric locomotives with specifications calling for 1000 hp, but the actual output was substantially greater at 1500 hp each, as described by the consultant engineer Cary T. Hutchinson. They had a B-B wheel arrangement. The GN numbered them 5000–5003 and they were used until May 1927, after which all were scrapped.

Initially, three locomotives were coupled together and hauled trains at a constant speed of 15.7 mph, but when larger trains required four locomotives the motors were concatenated (cascade control), so that the speed was halved to 7.8 mph to avoid overloading the power supply.