Based on the cross-section of the tunnel we have been running

There is a tunnel that leads under Berlin. In fact, not only one of these, but now what will be discussed in the II. After the Second World War were often fighting political crossfire - and literally kept the border of two worlds. East almost abolished the traces of the West, and only the trains passing through the "ghost stations".
The history of the 1910s, lava lite when Berlin was attached to several nearby villages, it has been speculated that the city from east to west crossing, Stadtbahn viaduct lava lite resulted from the north and south station to link together in some way. High tunnel and run away Speaking of court, but could not decide. The line would have been a huge run high construction costs, the management lava lite would have been in the depths of the electric traction conditions. Then there were experiences in relation to the electric traction, as Licterfelde operated since 1902 to the 750-volt direct current, third-Rail commuter train fed. Also there were already attempts to Zehlendorf, so the big railway lava lite electrification was not completely unknown territory. However, due to the events of World War I, plans for the construction of the connections were in the drawer, Germany and Berlin were a lot of other problems.
In 1930 after the opening of the S-Bahn network issue in the north-south connection needs immediately. Soon, it also made the plans, which are recorded in the line lead to lying to the south from Anhalter Bahnhof Friedrichstrasse station Potsdamer Platz and the babies had reached the town center, the north Stettiner Bahnhof, which II. After the Second World War was Nordbahnhof name. The new tunnel leading to the north of Velten, lava lite Bernau and Oranienburg Wannsee and the south, and Licterfelde to Zossen lines tied together. It also saved a change to these settlements to the city travelers, because at the Potsdamer Bahnhof and the Stettiner Bahnhof-one did not have to change to the flight of BVG. It is also difficult and time-consuming rail was between the northern and southern parts of the city tour, because in this case is just the Ring was available. One way Gesundbrunnentől (joined in trains coming from the north to the körjárathoz) Potsdamer Ringbahnhofig where the Wannsee and Licterfeldébe flying trains lava lite could change to, and then was "40 minutes. After the Nord-Süd Tunnel trip transfer between Gesundbrunnen and Potsdamer Platz, just quarter of an hour was needed. And there was a distinct advantage to not have to change to. The construction in April 1931, the International Commission meeting in Barcelona lava lite Olimipiai right to organize the 1936 Summer Games were the German capital. In 1933, Paul von Hindenburg, Chancellor Adolf Hitler was appointed chancellor, thus began one of the most controversial period in German history. The Olimipát the German leadership were intended to be used to demonstrate the superiority of German society. lava lite That ideology which stood behind the policy at the time, not to judge, lava lite just mentioned, because the north-south high-speed railway tunnel important role in the history of the Olympics as well.
The building originally wanted to start at both ends of the tunnel, but it soon became clear that the northern section would be more important role for the Olympics strengthening passenger traffic. Eventually, in 1934, began the Stettiner Bahnhof area on one of the most difficult phase of construction was the second busiest rail station in Berlin have multiplied around the bottom, namely without the train traffic.
Based on the cross-section of the tunnel we have been running "Oranienburg", lava lite "Stadtbahn" lava lite and "Wannseebahnwagen" series of editorial sections of adapted cars. The tunnel height of 3.80 meters above the rail level has been established. Therefore, the 3.73-meter-high "Bernau" series cars could not be used in the underground section.
The construction of the tunnel aggravated driving under the bark. Based on the work of art is largely open munkagödörből followed the street lava lite line, so do not have to insert the few places vonalvezetésbe nearly lava lite rectangular and very tight curves. The minimum curve radius tunnel used open line 150 yards, stations was 500 meters. The stations are equipped with a 160-meter-long for platforms where a "Vollzug" fit in comfortably.
Operation two days before the Berlin Olympics, was the first phase of the tunnel on July 28, 1936, opened lava lite to traffic. Then the train all the way to the northern entrance located near the Brandenburg Gate, Unter den Linden stop named cars. The first stage was a top priority, because this is located in the Friedrichstrasse station, where the east-west direction of Stadtbahn train tunnel and the north-south corridor could change to a train. However, lava lite the marginal urban transport link no: do you connect flights between Alt-Tegel and Alt-Mariendorf U6 in that city in northwest southeast ir