After the Second World War, the Arth-Rigi-Bahn initially ordered two new cog railcars, which were intended to cover demand at peak times, among other things. Like the previous locomotives, they only had a rack drive. For this purpose, each of the two-axle bogies had a traction motor that drove the cog wheel. A third vehicle was added in 1954. After initially being used with existing trailer cars without a control compartment, three control cars were purchased at the end of the 1950s to match the three power cars. The vehicles were later given the designation BDhe 2/4 11 to 13.

The fleet was only completed in 1967 with the delivery of another unit consisting of a power car and a control car. This was largely redesigned and, with increased external dimensions, also offered a new interior. It was called BDhe 2/4 from the start. In winter, both halves of the vehicle run with ski holders attached to the sides. The oldest vehicle was completely modernized in 1992, the others only received a new paint finish in 2005 and 2006. While they were previously blue at the bottom and white in the window area, today they are light blue in the window area, which slowly fades into white towards the bottom and is referred to as “snowflake painting”. In 2020, all vehicles are still in use on the Rigi Railways.