The Swiss Federal Tank Facilities Zollikofen (B.T.A.) owned, after the war, not only their own 4-axle tank cars of the standard and Deutz design but also former DRB cars, which were extensively reinforced in the 1950s due to poor experiences regarding sufficient strength in certain areas. Some were completely repainted, while others were only partially. Our set represents two such cars. This 2-piece tank car set "BTA," operated by SBB-CFF, consists of a 4-axle tank car of Deutz design, operating number 531077, and a 4-axle tank car of standard design, operating number 531051, in operational condition from 1958.