Since the BDhe 4/4 No. 14 railcar delivered in 1967 was still based on the CFeh 2/4 developed in 1947, the set of powercars and driving trailers ordered in 1978 was to be a modern design. It was basically based on the older design, but used a new powertrain technology with two traction motors per bogie. With the higher power, it was possible to push two of the historic trailers or to take freight wagons with them. At the same time, the Vitznau-Rigi-Bahn also needed new vehicles to increase capacity and ordered two identical sets, whose powercars were numbered 21 and 22.

Since the merger of the Arth-Rigi-Bahn and the Vitznau-Rigi-Bahn in 1992, the advantage for the crews has been that the vehicles are identical. In fact, the VRB staff was even trained on ARB vehicles because their own had not yet been delivered. The color scheme of the ARB was initially blue below and white above, but now it is also painted in the same white and light blue “snowflake paint” as the BDeh 2/4. The vehicles of the VRB are now kept in a similar livery, but the original red of the VRB has been used here instead of the light blue.