In 1942, Tnf Berlin (Tnfs38) came into being as a simplified refrigerator car. The basic design was provided by the Glmhs Dresden, as a welded version. In contrast to these, the refrigerator cars were given 300 mm thick insulation and zinc plate inner lining in order to protect the internal wood cladding against moisture penetration. In order to ensure that the doors sealed completely, the double-leaf revolving doors were replaced with sliding doors. However, the most significant change was the vertical panelling combined with the typical white paint of the refrigerator cars. From the mid-1950s onwards, the German Federal Railway (DB) carried out several design modifications and modernisation work on the coaches it had acquired. The maintenance-intensive wheelsets with slide bearings were replaced with roller bearings; car bodies were rebuilt with the same design if their insulating properties were inadequate. As a result, the coaches retained their main dimensions; however, the eye-catching car body frame was now hidden under horizontal panelling, and later even under laminated wood panelling. New refrigerator car developments at DB made it possible for private breweries to purchase a variety of cars from DB and use them for transporting their beer. Since these were private cars belonging to specific breweries, in most cases they were decorated with the company's own advertising.