Three-phase AC railway electrification was used in Italy, Switzerland and the United States in the early twentieth century. Italy was the major user, from 1901 until 1976, although lines through two tunnels also used the system; the Simplon Tunnel between Switzerland and Italy from 1906 to 1930 (but not connected to the Italian system), and the Cascade Tunnel of the Great Northern Railway in the United States from 1909 to 1939. The first standard gauge line was in Switzerland, from Burgdorf to Thun (40 km or 25 mi), from 1899 to 1933.[1][2]
- ^ Middleton (1974), p. 156.
- ^ Meares & Neale (1933), p. 630-631, para 919