1920 between Horb and Immendingen. For freight service, the Prussian G 12 as well as the Württemberg K were used. Starting in 1924, the Reichsbahn began to assign the Prussian G 10 to short-distance freight service, and between 1936 and 1938, the DRG Class 86 saw use in the same capacity. During World War II, passenger service was reduced in favor of the rather more significant freight traffic. The Mauser arms manufacturer in Oberndorf am Neckar was an important user of the line during the war, and Axis partner Italy received coal shipments from Upper Silesia using freight trains on the Gäubahn. The line lost much of its military freight significance in the North-South corridor with the German attack on the Soviet Union, and many of the newer locomotives, especially the Prussian P 10, were relocated by the Reichsbahn to eastern Europe, while passenger trains on the Gäubahn again saw the use of the Württemberg C locomotive. War damage, dismantlement, and electrification (1945–1990) Until February 1945, the Gäubahn did not suffer much damage during World War II, with the exception of aerial bombardment in 1944/45, which caused severe damage to the stations in Herrenberg, Horb am Neckar, Rottweil, Spaichingen, and Tuttlingen. This damage only disrupted traffic in the short term. In February 1945, Allied bomber wings destroyed a bridge in an attack on the town of Oberndorf, which was an important center in the German arms manufacturing industry. Even more significant was the damage caused by German troops in April 1945, when several bridges were blown up between Stuttgart and Böblingen, stopping train traffic altogether shortly before the end of the war. It was not until May 1946 that the railway was opened again for through traffic. Also in April 1945, American and French troops occupied southwestern Germany, which meant that the section of the Gäubahn between Bondorf and Stuttgart fell into the American zone of occupation, while the section between Ergenzingen and Singen was assigned to the French zone. France insisted on its right to reparations, unlike the United States of America, and in 1946 dismantled the second track between Horb and Tuttlingen, which had only been laid a few years before. Ever since, the Gäubahn is twin-tracked only between Stuttgart and Horb, as well as between Hattingen and Singen. The border between the American and French zones was responsible for the lack of through-traffic between Stuttgart and Singen,