In addition to the designs for mainline passenger coaches, which became known as "Donnerbüchsen" ("Blunderbusses"), the DRG also had plans drawn up for a series of "Branch line coaches 1921". The company considered a lower weight that for the mainline coaches and a shorter axle base to use narrow radii as very important. Due to a number of coaches considered sufficient for the next few years and a lack of financial means, only 74 passenger coaches and seven luggage cars were built in the end. For the Breslau 511-521 multiple units built from 1926 onwards for use in the electrified Silesian network, a total of 42 of them were converted to sidecars. If not already available, they were equipped with electric lighting and heating and the necessary control lines. Thus equipped, up to twelve sidecars travelled together with three multiple units to transport hikers in summer and skiers in winter to the heights of the Giant Mountains. The 40 coaches built as Di-24 and after 1928 reclassified as Cid-24 40 make up almost 50% of all standard branch line carriages built. Eleven of them received the necessary equipment for electrical push-pull train operation and were used from 1931 onwards on the Zackenbahn as "Breslau 2926-Breslau 2930" and "Breslau 2940 - Breslau 2945".
