The first electric trial runs using single-phase alternating current were made in 1903 on the line Seebach – Wettingen together with the Maschinenfabrik Oerlikon (MFO), using the future Ce 4/4 locomotives ("Eva" and "Marianne"). The electrification of the network started 1919, motivated by the coal shortages during the First World War, and new electric locomotives were introduced: Ce 6/8 II/Ce 6/8 III "Crocodile" (1920/1926), Be 4/6 (1920), Be 4/7 (1921), Ae 3/6 I (1921), Ae 3/6 II (1924), Ae 3/6 III (1925), Ae 4/7 (1927) and Ae 4/6 (1941). A shift of paradigms happened in 1946, when the age of modern bogie-based locomotives without trailing axles started with the Re 4/4 I (1946), followed by the Ae 6/6 (1952), Re 4/4 II/Re 4/4 III (1964/1971), Re 6/6 (1972), Re 450 (1989) and Re 460/Re 465 "Lok 2000" (1992/1994).