In the ruined landscape that was once Berlin, an improvised normality began unbelievably quickly. After the end of the war the city’s infrastructure had to be brought back on line. The flooded north-south tunnel – where it was thought that there would be thousands of dead – presented the danger of an epidemic. Therefore the Soviet city commander ordered that repair work begin immediately in May 1945, however it took a further 10 months until the tunnels were in a condition that trains could travel though them. In September 1945 it was still possible to inspect the tunnel with inflatable boats. After the damaged sections were sealed, 1.9 million cubic metres of water were pumped out of the tunnel. There 93 dead and 102 train carriages were found in the masses of sludge.
Another problem lay in the clearing of the estimated 60-70 million cubic metres of rubble. The amount equates to a 30 metre-wide and 9-10 metre-tall embankment that would stretch from Berlin to Hamburg. The debris was piled up into rubble-mountains at various points in the city. A survey of the damages in Berlin showed that 28 per cent of above ground buildings and 5 pro cent of its underground buildings were completely destroyed. The centre of the city was disproportionally affected, with often more than 80 per cent total destruction.
As a result of the Berlin Blockade, the city’s infrastructure was gradually divided. Aside from the canalization and train tunnels, all lines connecting the two halves of the city were capped by 1952. In February 1949 the pneumatic post connection was disconnected from East Berlin, so that “no subversive messages from the west sector can make their way to the democratic sector of Berlin” – as they put it. Shortly afterwards the telephone, electricity, and water supply lines were cut – only the gas lines were severed from the western side.
It didn’t take long before the underground was the setting for a Cold War conflict. In April 1956 The Soviets discovered a 450 metre-long spy tunnel belonging to the British and American secret services in the south of Berlin – known as “Operation Gold” – that was used to listen in on the East Berlin telephone lines. Because of this, the East Berlin press referred to the attempt about a year later of three West Berliners to use the heating tunnel from the Reichstag ruins to get into the east, as another case of the American moles trying to spy on the east.
Finally, with the building of the Berlin Wall on the night of the 12th/13th of August 1961, the underground transportation network was divided. The U and S-Bahn stations of the underground lines that crossed between east and west were quickly sealed. The U-Bahn station Potsdamer Platz – today part of the U2 – was also affected. The workers of the BVG (Berlin transit authority) from the west and the east were sitting together drinking coffee at 11pm when the station was stormed by East German police and the West Berliners were sent home. A few weeks later the tunnel leading to the west was walled shut.
Attempts to dig tunnels under the wall followed the sealing of the canalization. More than 40 of these attempts are known, however the majority failed, mostly as a result of betrayal. Constantly improving surveillance methods, like microphones used to listen for digging, made tunnelling a very dangerous activity. The last known tunnel escape was in 1972, wherein three East Berliners dug for twelve nights from the cellar of the old Bewag (power company) building, under the “death strip” of the Berlin Wall on Zimmerstr, to Kreuzberg. The first time they tested to see if they had reached the west, they found themselves two metres short of the wall. Luckily, “Operation Mole” wasn’t discovered, and the escapees were able to dig further and reached West Berlin. Shortly later, as a result of a routine search, the entrance of the tunnel was discovered.
After the 13th of August 1961, trains no longer stopped at many of the underground stations in the city’s centre. The exits were systematically barred or bricked up. Only patrols and border guards passed through this spooky no man’s land. All of the stations in East Berlin of the U6, U8 and north-south S-Bahn lines were closed, and West Berliners travelled through them without stopping. The only exception was Friedrichstrasse station, now a border crossing point, where it was possible to get on and off the train. A white line on the walls of the tunnel marked the border in the tunnels.
The transit lines and the ghost stations were an absurdity under the divided city. West Berlin paid a yearly fee of millions of Deutschemark for the use of these lines. Trains had to pass at a walking pace through the restricted stations, which were guarded by border guards and transport police. It was a closely guarded secret that the guards were forbidden to use their weapons in the tunnels, for fear of the bullets ricocheting around, yet there were other security measures taken to foil escape attempts.
In 1967, forgotten tunnels of the Germania plans were rediscovered under the Soviet war memorial in the Tiergarten. Rumors that circulated about a possible underground connection to the east part of the city gave the Stasi (East German secret police) a fright. Since no records were found detailing the clearing of the area, instructions were issued to perform a comprehensive survey of the site. The goal was “to register subterranean structures (untertägige Anlagen) – UTA for short – that may be used for provocations or attacks on the border of the capital of the GDR”.
In the following years a total of 16 buried bunkers were laid open and documented, amongst them the bunker of the New Reich Chancellery. The Fueher Bunker was also reopened, and after the ground water was pumped out, it was meticulously measured and photographed. In the mud old documents were found, including Joseph Goebbels’s diaries, yet these soon disappeared again into the dark corridors of the Stasi. The “Adlon Bunker” and the bunkers of the various other government ministries of the Third Reich were also opened, although no other surprises were found. In 1975, the survey came to the tentative conclusion that secret tunnels connecting to the west part of Berlin could not be found.