At the beginning of the seventies, the older types of rail mail cars could hardly be used profitably. Even the first new wagons built in 1952/53 were only usable to a limited extent at 120 km / h.Therefore, the German Federal Post Office ordered new rail mail cars in 1973.By 1976, 200 cars had been produced, which were known as "Post March". Originally approved for a top speed of 140 km / h, the conversion and upgrading for 200 km / h took place in 1979.These cars could also run in IC and EC trains. The 200 km / h fast Post IC trains were the main area of a€?a€?application for these cars, which were painted green at first and later ocean blue / beige, until the mid-nineties.After the post wagons were decommissioned, some were sold to private companies, including RailAdventure, which uses these wagons as coupling wagons for vehicle transfers.