Fourteen units of this powered rail car were delivered as early as the opening of the Bernina Railroad between 1908 and 1910. In 1943, the Bernina Railroad was taken over by the Rhaetian Railroad (RhB), including these powered rail cars – they had not yet reached the end of their useful lives. However, their performance left something to be desired. The RhB thus began to update the existing units in its own shops. The most striking thing was the replacement of the "harp" pantographs with a double-arm pantograph and the conversion of the acceleration and braking resistors. The latter were previously installed under the car body and were now up on the roof. The delivery of new powered rail cars pushed these units increasingly into lesser duties. However, they were not retired – at the grand old age of 100 years – until the new Allegra powered rail cars were delivered in 2010. Yet two powered rail cars – road numbers 30 and 34 – survived. Restored to their original yellow paint scheme, they are still currently used in special train service pulling historic trains.