U2 is a line of the Berlin U-Bahn. The U2 line starts at Pankow S-Bahn station, runs through the eastern city centre (Alexanderplatz) to Potsdamer Platz, the western city centre (Wittenbergplatz, Zoologischer Garten, Theodor-Heuss Platz) and finally to the Ruhleben terminal station.
The U2 has 29 stations and a length of . Together with the U1, U3, and U4 lines, it was part of the early Berlin U-Bahn network built before 1914. The line between Potsdamer Platz and Zoologischer Garten was the western section of the "stem line" (Stammstrecke), Berlin's first U-Bahn line opened in 1902.
Overview
The line starts to the west of central Berlin at Ruhleben and runs on an embankment between Rominter Allee and the railway to Spandau (also called the "Olympic" or "Grunewald" railway). On the bend approaching Olympischen Straße, the line descends into tunnel to run beneath that road from Neu-Westend to Wittenbergplatz. Subsequently, the U2 swings onto Reichsstrasse to Theodor-Heuss-Platz, where it runs in a curve to Kaiserdamm. Under Kaiserdamm, which becomes Bismarckstraße at Sophie Charlotte-Platz, the tunnel runs straight to Ernst-Reuter-Platz. Here again, it swings to the southeast, following the course of Hardenberger Straße towards Zoologischer Garten station. In the tunnel, it passes the foundations of the Kaiser Wilhelm Memorial Church on a tight arc and then follows Tauentzienstraße to Wittenbergplatz where the line emerges to an elevated section via a ramp east of the Kleiststraße/Courbierestraße intersection.
The elevated railway reaches its full height at Nollendorfplatz station where all four lines of the small-profile network meet. The underground part of the station has four tracks. The U2 continues above ground to the east of Bülowstraße. After that the U2 makes a curve over a long viaduct at the southernmost point of the line, passes through Gleisdreieck station and then runs straight across the Landwehr Canal and returns underground between Mendelssohn Bartholdy-Park and Potsdamer Platz stations.
While the elevated railway company intended to continue the line along Leipziger Straße, it was not permitted to build this route and instead it continues instead along Anton-Wilhelm-Amo-Straße, Markgrafenstraße and Niederwallstraße to the River Spree in Berlin Mitte. After passing Märkisches Museum station, it goes under the River Spree in a tunnel, and runs through Klosterstraße to Alexanderplatz station.
After leaving Alexanderplatz, the line turns under Rosa-Luxemburg-Straße and through Rosa-Luxemburg-Platz station. The line then runs north underneath Schönhauser Allee and through Senefelderplatz station. Before reaching Eberswalder Straße station, the line emerges from tunnel and on to an elevated viaduct through to Schönhauser Allee station, an interchange with the S-Bahn. From there the line runs beyond the former city limits and the elevated railway descends again into a tunnel to Vinetastraße before reaching the terminus at Pankow.
Route numbering
Since the introduction of the schematic line network plans at the Berlin subway, at least parts of today's line U2 always had the colour red. When letters were introduced as a line name after the First World War, the small profile network received the letters "A" and "B". The inner city route, more important than the older route through Kreuzberg, became line A, as did the two western branches to Charlottenburg and Dahlem (today's U2 and U3 lines). The routes from Kurfürstendamm and Schöneberg through Kreuzberg to Warschauer Straße (today: U1 and U4) were given the letter "B" and the colour code green. To distinguish the branches in the western part of the line, the letters were supplemented by Roman numbers, the Charlottenburg route was thus the line AI.
From 1966, the designation of the lines operated by the Berlin public transport companies (BVG West / BVG) in West Berlin was converted to Arabic numbers. Each line was now operated independently and without branching. The ("green") line 1 now ran from Ruhleben through Charlottenburg to Kreuzberg, while the previous AII became the ("red") line 2 (Krumme Lanke – Gleisdreieck, from 1972 only to Wittenbergplatz). The severed eastern line section, used since 1949 by the BVG East / BVB, retained the "A" line designation unchanged, as well as the red colour code.
On 9 January 1984, the BVG also took over the S-Bahn lines in West Berlin previously managed by Deutsche Reichsbahn. The marking of the U-Bahn lines operated by the BVG changed again because the U-Bahn and S-Bahn lines were now operated in parallel. To better distinguish the two networks, the respective Arabic numbers, which had been used since 1966, were prefixed with the letter "U" to provide a line number. According to the model of public transport networks, which were used in various cities (Frankfurt, Shanghai, Munich, Beijing, Guangzhou) they were then designated as U1 to U9 and similarly the acquired S-Bahn routes were preceded by "S".
With the merging of Berlin in the context of German reunification and the reconstruction of the disused Wittenbergplatz–Anton-Wilhelm-Amo-Straße section in 1993, the BVG decided to swap the western branches of lines U1 and U2, which meet at Wittenbergplatz. The reunited former AI line has since been operated under the new name "U2", but using the traditional red line colour as previously used in the separate parts of the city.
History
The increasing traffic problems in Berlin at the end of the 19th century led to a search for new efficient means of transport. Inspired by Werner von Siemens, numerous suggestions were made for overhead conveyors, such as a suspension railway, as was later built in Wuppertal, or a tube railway as was built in London. Finally Siemens and some prominent Berliners submitted a plan for an elevated railway on the model of New York. These people opposed Siemens' suggestion of building an overhead railway in the major street of Friedrichstraße, but the city of Berlin opposed underground railways, since it feared damage to one of its new sewers.
Finally, after many years and negotiations, Siemens proposal for an elevated railway line from Warschauer Brücke via Hallesches Tor to Bülowstraße was approved. This was only possible, however, because it passed through poor areas. The richer residents of Leipziger Straße pressed the city administration to prevent the line using their street. Siemens & Halske carried out all construction work and also owned the line. The first sod was turned on 10 September 1896 in Gitschiner Straße. The construction work had to be carried out quickly because the contract with the city of Berlin, signed with the granting of the concession, specified that the line had to be finished within two years, or a penalty of 50,000 marks would be payable.
The railway engineers developed a design for the supporting columns for the elevated railway, but it was unpopular and the architect Alfred Grenander was asked to submit an artistic solution for this problem. For the next 30 years Grenander was the house architect for the elevated and underground railway.
After tough negotiations with the city of Charlottenburg it was decided to extend the line to Knie along the Tauentzienstraße, but instead of being elevated it would be a subsurface (cut-and-cover) railway. The management of the city of Berlin board of works regarded the idea of an underground railway sympathetically. Since the underground caused no apparent damage to the new sewer, an underground branch could be built from a junction at Gleisdreieck (German for "rail triangle") to Potsdamer Platz, Berlin's then city centre. The national government granted permission for the planning changes on 1 November 1900.
The total length of the elevated and underground railway was now . The largest part of the route, approximately , would be established on viaducts and connect eleven elevated stations. In addition there would be of underground line with three underground stations. The planners believed that 8-carriage trains would not be needed and therefore designed it with -long platforms, sufficient only for 6-carriage trains.
The first of the line was finished in 1901 and on 15 February 1902 the first train ran on the line from Potsdamer Platz to Zoologischer Garten, then to Stralauer Tor and back to Potsdamer Platz. This allowed many prominent Berliners to participate in the opening trip, including the Prussian minister for public works, Karl von Thielen. On 18 February 1902 the first stage of the Berlin U-Bahn was officially opened (Stralauer Tor–Potsdamer Platz). In March the line was extended to Zoologischer Garten and on 17 August it was extended by from Stralauer Tor to Warschauer Brücke. There were at that time only two lines: From Warschauer Brücke to Zoologischer Garten via Potsdamer Platz (with reversal). From Warschauer Brücke directly to Zoologischer Garten.
On 14 December the line was extended to Knie. The section between Gleisdreieck and Knie (now Ernst-Reuter-Platz) is now part of U2.
Charlottenburg extension
After the opening of the original route further plans to extend the three route branches emerged: via Charlottenburg city to Wilhelmplatz (now Richard-Wagner-Platz) and towards Reichskanzlerplatz (now Theodor-Heuss Platz), from Potsdamer Platz to the centre of Berlin and via Warschauer Straße to Frankfurter Tor The fastest route negotiations were completed with the young and coming city of Charlottenburg because there was a lot of vacant land that could be developed. The most important negotiating point was to build a route via Charlottenburg Town Hall in Wilhelmsplatz. Here an extension along Berliner Straße (now Otto-Suhr-Allee) would have served, but this was served at the time by the and a parallel line did not seem sensible. Therefore, this line would continue under Bismarckstraße to the west and then curve to the town hall. Under the working title of Krumme Straße, the line was initially planned with a station at Bismarckstraße (now Deutsche Oper) and a terminus at Wilhelmplatz. The line was opened between Knie and Wilhelmplatz on 14 May 1906. Both U-Bahn lines now ran to Bismarckstraße, but only the branch to Potsdamer Platz also ran to Wilhelmsplatz.
While this line was under construction, the railway company and the city of Charlottenburg agreed on a branch towards Westend. Therefore, a planning amendment was necessary at the planned station at Bismarckstraße, because the line to Westend would branch there. Therefore, the station was built as the first four-track U-Bahn station in Germany. The two inner tracks would be used for the line to Wilhelmsplatz and the outer tracks for the line to Westend.
Since the western Charlottenburg area was still completely undeveloped, the line would not generate any profits in its early years. Therefore, the elevated railway company negotiated with the city of Charlottenburg and the other property owners to compensate for the line's deficit. This contract was signed on 23 June 1906.
For the line westwards through Charlottenburg, the following stations were to be built: Bismarckstraße (today's: Deutsche Oper) Sophie-Charlotte-Platz Kaiserdamm Reichskanzlerplatz (now Theodor-Heuss-Platz, the terminus)
On 16 March 1908, the Emperor Wilhelm II, opened the line, following the "ministerial trip", the first service on the line. It was officially inaugurated on 29 March 1908. The two existing lines did not continue to Reichskanzlerplatz; instead, a third line was established, operating only between Bismarckstraße and Reichskanzlerplatz.