The "Jumbo" for heavy freight cars

The Deutsche Reichsbahn Gesellschaft’s (DRG) procurement process for standardised freight locomotives mirrored its earlier evaluations of the 01 and 02 series. According to the specification, the new locomotive had to be capable of hauling goods trains weighing up to 1,200 metric tons over low mountain ranges, with an axle pressure of 20 tons.

The maximum speed was set at 70 km/h for the pre-series locomotives. In 1926, to determine the most economical design, orders were placed with various locomotive manufacturers for the construction of 10 locomotives each of the 43 (two-cylinder engine) and 44 (three-cylinder engine) series. In addition to allocating the locomotives to other railway depots, a direct comparison was made between the 43 and 44 at the Pressig-Rothenkirchen depot. The respective merits and shortcomings of both series were determined via tests on the Franconian Forest Railway. The comparison of the two series did not initially favour the more powerful 44 series – the increased economy offered by the two-cylinder type 43 locomotive won the day. However, as Germany emerged from the shadow of the Great Depression in the mid-1930s, calls for more powerful freight locomotives grew louder. The experience gained ten years earlier with the type 44 was still fresh in the memory. The type 44 013-065 locomotives were consequently developed as an intermediate series – in part based on the experience gained in steam engine construction since 1925. In 1938 (from 44 066), full series production finally began. By 1949, a total of 1989 type 44 locomotives had been built at various locomotive factories in Germany and abroad. The new models lived up to all expectations and henceforth became the backbone of the goods train fleet.