Planning for an underground railway in Vienna can be traced back to the 1840s. Since then, there have been numerous plans and concessions to build such a project, making Vienna the city with the most subway planning. The concession request of the engineer Heinrich Sichrowsky dates from 1844 with the idea of a pneumatic, or atmospheric, railway based on the system of Medhurst and Clegg. The trains would have been advanced pneumatically by stationary steam engine air pumps. Sichrowsky’s route would have led from Lobkowitzplatz, below the Vienna Glacis, and along the Wien River to Hütteldorf. Although such trains had been built in London and Paris, it found in Vienna no investors for its stock company, so this idea was rejected. The connecting railway project of Julius Pollak (1849) was also conceived as an atmospheric system. Sichrowsky's request was the starting point for a series of plans that were mostly not approved and could not be implemented. For example, in 1858 the city planner Ludwig Zettl proposed to make an overburden of the former moat instead of filling it, and then to set up a railroad tram in this enclosed ditch, which would bypass the city. This would have created a connection between the central station and the market halls, while at the same time the gas-lit tunnels were to serve as warehouses for food. By 1873, at least 25 plans for a municipal railway system came up, with only the Verbindungsbahn, which already appeared in the much larger overall plan by
Carl Ritter von Ghega in his project for Vienna's urban expansion of 1858, being later implemented as part of the mainline railway line. Ghega had already worked out a belt railway project along the line wall in 1845. The first planning for a subway in deep-seated tunnels by
Emil Winkler dates back to 1873, with planning proposals that were also based on the first systematic traffic census in Vienna. Another wave of public transport projects were developed as the
ring road was close to be finished. The conception of the British engineers James Bunton and
Joseph Fogerty won out, since their plans, approved in 1881, included trains to be run in tunnels, in open incisions, and on elevated tracks. In 1883, the project of an "electric secondary railway" of the company
Siemens & Halske planned for a small profile rail system with three lines. The construction failed due to the concern of the city council that inner city business life could be affected, especially since the project for the first time ever included a tunneling of the city center. , in
Jugendstil style by Otto Wagner The first system to be constructed was a four-line
Stadtbahn railway network (which had been planned to have three main and three local lines) using steam trains. Ground was broken in 1892, and the system was opened in stages between 11 May 1898 and 6 August 1901. At
Hütteldorf, the Stadtbahn connected to railway service to the west, and at
Heiligenstadt, to railway service on the Franz Josef Line, which then ran northwestwards within the
Austro-Hungarian Empire to
Eger. Some of the
Jugendstil stations for this system designed by
Otto Wagner are still in use. However, the Stadtbahn proved inadequate for mass transport, less successful than the tramway. Starting in 1910, plans were considered for an underground system, but were interrupted by the
First World War, which also necessitated closing the Stadtbahn to civilian use. After the war, the economic situation of a smaller and poorer country ruled out continuing with the plan. However, starting on 26 May 1924 the Stadtbahn was electrified, something that many had called for before the war, and from autumn 1925 it was integrated with the tramway rather than the railways. The frequency of trains tripled. Plans for a U-Bahn dating to 1912–14 were revived and discussions took place in 1929, but the
Great Depression again necessitated abandoning planning. Both in 1937 and after the
Anschluß, when Vienna became the largest city by surface area in
Nazi Germany, ambitious plans for a U-Bahn, and a new central railway station, were discussed. Test tunnelling took place, but these plans, too, had to be shelved when the Second World War broke out. Severe war damage caused the Stadtbahn system to be suspended in some areas until 27 May 1945. The redevelopment of stations took until the 1950s. Meanwhile, Vienna was occupied by the four allied powers until 1955, and in 1946 had returned three quarters of the pre-war expanded Greater Vienna to the state of
Lower Austria. Two proposals for U-Bahn systems were nonetheless presented, in 1953 and 1954. Increasing car traffic led to cutbacks in the S-Bahn network that were partially made up for by buses. The U-Bahn issue was also politicised: in the 1954 and 1959 city council elections, the conservative
Austrian People's Party championed construction of a U-Bahn, but the more powerful
Social Democratic Party of Austria campaigned for putting housing first. The city council repeatedly rejected the U-Bahn idea in the late 1950s and early 1960s. Extensions of the Stadtbahn system had always been discussed as an alternative to building a new U-Bahn. But it was not until the late 1960s, when the Stadtbahn and the Schnellbahn were no longer able to adequately serve the ever-increasing public traffic, that the decision to build a new network was taken. On 26 January 1968, the city council voted to begin construction of a basic network (
Grundnetz). Construction began on 3 November 1969 on and under
Karlsplatz, where three lines of the basic network were to meet, and where central control of the U-Bahn was located. Test operation began on 8 May 1976 on line U4, and the first newly constructed (underground) stretch of line opened on 25 February 1978 (five stations on U1 between Reumannplatz and Karlsplatz). An additional , three-station extension of the U2 to Aspern
Seestadt was officially opened on 5 October 2013.
Fourth expansion phase (since 2010): Further extension of the Vienna U-Bahn Planning for a fourth U-Bahn expansion phase began in 2001 and concrete ideas were put forth in the 2003 Transport Master Plan. This was achieved by expanding the pre-existing route of tram line 67. The change to the original plans was thought to be due cost issues or the incomplete development of the area surrounding Rothneusiedl. This extension was ultimately opened to the public on 2 September 2017, thereby expanding the Vienna metro network by and 5 stations. In the area of the station Alaudagasse preparations for a future line bifurcation were made, should the further development in Rothneusiedl warrant a branch line there.
Further expansion options Other possible expansion options are: • Expanding the U5 beyond Hernals to Dornbach • Expanding the U5 beyond Karlsplatz as was planned in the 4th expansion phase for the U2
Timeline ==Rolling stock ==