Covered goods wagons are almost as old as the railway itself and mainly serve the transport of piece goods. In the 1950er, the Deutsche Reichsbahn (DDR) was only able to maintain the demand for these vehicles by retrofitting and modernizing older G-cars. In 1966, the RAWUnityLeipzig began with the construction of a Glmms model car with silted sheet metal walls lined with wood on the inside. This type went into series production at the Gothaer wagon factory from 1968 and was called Glmms 14.05 (from 1977 as GBS 1500).The welded structure, with its distinctive side walls, reached down to the lower edge of the outer frame carrier and was connected to the box profiles. This meant that the conventional car body supports could be dispensed with. Most of the cars were built with reinforced doors. The floor was suitable for loading forklift trucks and consisted of pine beams.By 1983, more than 17,000 pieces of the GBS 1500 construction were produced. Among them various designs as heat prot