railcars on its high speed network. The potential of these express trains was demonstrated by the in its record run on 21 June 1931 when it reached a top speed of . Before the Second World War the most important railway lines ran in an east–west direction. The high-speed lines at that time were on the Prussian Eastern Railway which ran through the Polish corridor (albeit slower there due to the poor state of the tracks), the lines from Berlin to Hamburg, via Hanover to the Ruhrgebiet, via Frankfurt am Main to southwest Germany, on which the diesel express trains ran, and the Silesian Railway from Berlin to Breslau (now Wrocław). Bavarian Group Administration Within the state of Bavaria, the Bavarian Group Administration () had its head office () and was largely independent by § III 14 of the DRG's company regulations. It was responsible for the electrification of many lines, following the commencement of electric power generation to the railways at the Walchensee Power Plant, and for the independent trialling and procurement of locomotives and passenger coaches. The Group Administration introduced, for example, the Class E 32 locomotive and Class ET 85 railcar into service. Bavaria also continued to use its own signalling system for many years after the merger. In 1933 the Group Administration was disbanded and administration of the railways in Bavaria was taken over by the Deutsche Reichsbahn. Leadership of the Reichsbahn At the head of the Reichsbahn was a director general (). The office holders were: 1924–1926 Rudolf Oeser 1926–1945 Julius Dorpmüller From 1925, the director general had a permanent deputy. These were: 1925–1926 Julius Dorpmüller 1926–1933 Wilhelm Weirauch 1933–1942 Wilhelm Kleinmann 1942–1945 Albert Ganzenmüller As a result of the Reichsbahn Act of 11 July 1939, the Reich Transport Minister became the director general of the Reichsbahn by his office. Dorpmüller, who since 1937 was also in charge of the Reich Ministry of Transport, continued in office as the director general after 1939 under this new legal framework. Deutsche Reichsbahn (1937–1945) With the Act for the New Regulation of the Conditions of the Reichsbank and the Deutsche Reichsbahn () of 10 February 1937 the was placed under Reich sovereignty and was given the name . World War II and military use The had an important logistic role in supporting the rapid movement of the troops of the Wehrmacht, for example: March 1938: the annexation of