The competition from trucks starting in the mid-Twenties caused the DRG to emphasize less-than-carload-freight. The pioneering concept: self-contained trains and the sorting of piece freight in route. A lot was improvised on the so-called "Leichten Eil-Güterzüge" / "Lightweight-Fast-Freight-Trains" (Leig). With the limitation on train lengths, the end effect was that stops could be made exactly at station platforms and the freight transfer could be accelerated accordingly.
Prototype: Type Gllmhs 37 Leig-Einheit / less-than-carload-lot pair of cars with the lettering "Stückgut Schnellverkehr" / "Less-than-Carload-Lot Express Service". German Federal Railroad (DB). The cars look as they around 1958.