track replacements due to heavier than anticipated passenger load. This necessitates the planning of new U9 line as to reduce the burden on U3/U6 line. No 24-hour service is offered due to the nightly maintenance. Instead, the night buses are used. History Already in 1905 there were plans to build an underground metro in about the route of today's trunk line of the S-Bahn between the main and Ostbahnhof and a ring road that surrounds the old town. Since these plans for the then traffic were clearly oversized, they came back into oblivion. The tram network was able to cover the traffic flows in the former half-million city. From 1910, the only 450 m long, automated Munich subway metro connected the main station with the post office on Hopfenstraße. It served only for the transport of letter post. In 1928 there were again plans to replace the trams in Munich by a subway network, but any such plans for this were thwarted the global economic crisis. A network of five subway routes, which had some similarities with today's route distribution, was to be realized. At the time of Nazi Germany, from 1936, a network of electric subterranean railways was planned for the "capital of the movement" and construction was begun, but the Second World War put an end to this. The tunnel of today's U6 between Sendlinger Tor and Goetheplatz - including the station there - were already completed in the shell, but still as part of a rapid-transit railway route. This also explains the relative generosity of Goetheplatz (especially in the blockade entrance Goetheplatz does not fit the architecture today) and the narrowness of the present interchange station Sendlinger Tor on the platform U3 / U6. In the Lindwurmstraße took place on 22 May 1938, the groundbreaking ceremony for this tunnel, which should herald the beginning of the end of the tram. By 1941, the shell was completed, first railcars were to be delivered in the same year. The war-related scarcity of resources led to the cessation of this work. The shell was used during the war as an air-raid shelter, of which today still bears inscriptions on the tunnel walls. Parts of the tunnel were filled with debris after the war, others served for a while as a breeding ground for mushrooms, before penetrating groundwater made the short piece of early metro history unusable. The Nazis forbade the