The U5 gap closure will extend Berlin’s U5 underground line from Alexanderplatz to Brandenburger Tor and connect it there with the already completed U55. The U5 and U55 will merge to form one line: the new U5, which will run from Hönow to Hauptbahnhof.
The BVG AöR as a building owner erected the new route on contract of the Berlin Senate with federal and state funds. The PRG U5 was founded in 2014 to take over project management.
The new line section is 2.2 kilometres long. It runs from Alexanderplatz past Berlin City Hall. Then it crosses under the Marx-Engels-Forum, the Humboldt Forum, the Spree and the Spree canal, before wending its way below the Unter den Linden boulevard to Brandenburger Tor underground station. On connection with the U55 section, 1.5 kilometres long, and the 18.3 kilometres of the present U5, the new U5 from Hönow to Hauptbahnhof will have a length of 22 kilometres.
The U5 gap closure will create three new underground stations:
Underground station Rotes Rathaus is located directly in front of City Hall, below Rathausstraße.
Underground station Museumsinsel extends south of the Palace Bridge beneath the Spree canal.
Underground station Unter den Linden is a new interchange for the U5 and U6 and located under the junction of Unter den Linden and Friedrichstraße.
The closure of the gap between the U5 and U55 will create a direct connection between the eastern parts of the city, the historic centre, the government district and the Central Station. In addition to the direct link with Bundestag and Brandenburger Tor stations, the Central Station will also be connected to the entire Berlin underground network. Passengers will finally be able to change directly from line U5 to the U6 and the north/south S-Bahn. The new connection also relieves the strain on the S-Bahn and the U2 on weekday commutes.
We currently have a budget of 525 million. The project is funded by federal and state funds.
As the developer, the Berliner Verkehrsbetriebe (BVG) is building the new line on commission of the Berlin Senate using federal and state funding. In 2014, the BVG commissioned Projektrealisierungs GmbH U5, a wholly-owned subsidiary, to take over work on the U5 gap closure project.
The symbolic ground-breaking ceremony for construction of the U5 gap closure was held in April 2010. Construction works started in 2012. Based on previous construction progress, we expect commissioning in late 2020.
Most of the tunnel for the U5 gap closure – from Marx-Engels-Forum to Brandenburger Tor station – was built using the shield tunnelling method. Tunnel boring machines are in principle rolling factories that move through the subsoil and, in addition to boring, also create the tunnel carcass. The machine we were using was specially designed and configured for this particular construction project. It will excavate two separate main tunnels through the finished station pits.
The machine is the property of construction firm Implenia Construction GmbH. Like all tunnel boring machines made by Herrenknecht, Bärlinde was custom-built. She was developed specially for the U5 gap closure and the geological conditions of the subsoil in the centre of Berlin, and cannot readily be used on another construction project.
Manufacturer Herrenknecht takes back used machines to reprocess certain parts and use them again on new machines. Bärlinde, for example, in part consists of elements that were previously used for the U4 line in Hamburg. It is ultimately the responsibility of the construction firm to decide how the machine will be reused or recycled at the end of the tunnel boring process for the U5 gap closure.
The future southern entrance to Unter den Linden station is located only a few metres from today’s northern entrance to Französische Straße station.
Französische Straße station will be retained as a structure but removed from the underground network. The entrances will be sealed and trains on the U6 will pass through the station without stopping. A new use for the Französische Straße station – as an event venue, for example – may be possible in the future. Any such decision will be taken by the Berlin Senate.