Seebach-Wettingen test locomotive No 1 Eva Oerlikon Engineering Works MFO 1902 Single-phase alternating current has many advantages for railways. Its voltage can easily be altered with transformers, and only one contact line is needed. Initially, however, there were no traction motors available to run on such a supply. The MFO engineers used this locomotive to experiment with various types of single-phase alternating-current traction, being convinced that this type of supply system should be used for main-line railways. MFO SLM 40 t 60 km/h 294 kW in service CFF 1919-1940 ВТ Railway 1940-1958 restored by CFF MFO