Starting in 1971, the Rhaetian Railway RhB procured four three-car Be 4/4 electric multiple units, primarily for suburban traffic in Chur. At the time, the four-motor push-pull trans trains were the first traction vehicles in Switzerland to have thyristor control. The 784 kW strong reached a top speed of 90 km/h. In addition to an electro-pneumatic air brake, the three-part vehicles also decelerated with the electric regenerative brake. In 1979, the RhB ordered two more, largely identical trains. From 1988, four additional intermediate cars were put into service to form four-car trains. Despite multiple modernizations, the traction motors were still the same until they were phased out from 2021 as when they were put into service 50 years earlier.

Make sure that index CV31 is set to 16 and index CV32 is set to 1 before changing a volume CV.