Before the war, standardised large containers were already beginning to be transported right to the customer with rail and road vehicles. The outbreak of the Second World War stopped the further spread of the system, however. In 1949, the Deutsche Bundesbahn (DB) returned to the "pa" container system (pa: French abbreviation for "porteur amâ€‚nager") and decided to introduce it on a large scale. While the containers were newly constructed, the DB fell back on underframes of various pre-war wagons that were available in ample numbers, but had suffered war damage to the superstructures. During the conversion work, undercarriages from Omm 34, which were classified as BT(hs) 30, were used in a common number range with BT wagons repurposed from other donor wagons. After the refurbishing of a total of 273 BT 30, the exclusively new construction of container waggons started in 1952. Shortly after being renumbered in Lb(r)s 577, the last refurbished BT 30 waggons were taken out of service in 1971. There were numerous open and closed containers for the greatest variety of cargoes, and moreover, there were special containers for liquids, foodstuffs such as beer, and for the transport of frozen goods. From the end of the 60s, increasingly crowded out by the emerging containers, transport with the "pa" containers ceased at the end of the 90s.