When Hamburg completed the reconstruction of destroyed buildings in the 1950s, the port was humming and with it the entire economy, the Senate set up the "Commission for Transportation Issues" to develop a sustainable transportation concept for the Hanseatic city. Public transportation played a decisive role in this, and the subway network was to double its length to up to 100 kilometers. At the same time, the tasks of the transportation systems were reorganized: On the important traffic axes, subways were to provide direct and reliable connections to the city center. In the surrounding areas, buses took over traffic development and at the same time fulfilled the feeder function to the rapid transit systems. The streetcars, on the other hand, which were making increasingly poor progress on streets clogged with cars, were gradually phased out and replaced by flexible buses.

The Wandsbek line

The new concept came to full fruition during the construction of the subway line to Wandsbek, which was planned from 1955. Starting at Jungfernstieg and running via Meßberg, Hauptbahnhof, Wandsbek Markt to Wandsbek Gartenstadt, the line connected important residential neighborhoods such as Eilbek and Dulsberg to the subway. As a fast direct connection to the city center, the line at Wandsbek Markt also fulfilled an important bridging function in Hamburg's east. This was because numerous bus lines ran from what was then the most modern bus facility in Europe, for example to Jenfeld, Tonndorf and Rahlstedt, Bramfeld, Horn and Billstedt, and ensured that the area was connected to the subway. In the city center, the area around Meßberg was also opened up to traffic, and at the main train station, a transfer facility to the ring line was created, which strengthened the interconnection of the subway lines.

Large sections could be built openly because of the gaps between buildings and free areas, and new types of prefabricated components were used in tunnel construction, both of which saved time and money. In the case of the 550-meter-long undercrossing of the railroad tracks at the main station, where open cut construction was not possible, the new shield tunneling method was used for the first time in Germany and worked so well that it was also used in the future. The fact that HOCHBAHN was responsible for equipping the station with tracks, signals and all the necessary electrical equipment, and that the construction authority was responsible for the actual construction work, also helped to complete the project quickly.

The Meßberg stop opened in February 1960, followed by Steinstrasse and Hauptbahnhof Süd on October 2. On July 2, 1961, the line was completed as far as Lübecker Strasse, in October as far as Wartenau, and the section as far as Wandsbek Markt went into operation together with the bus interchange on October 28, 1962. Barely six months later, the last two stops, Straßburger Strasse and Alter Teichweg, were completed and the connection to the Walddörfer Bahn was made at Wandsbek Gartenstadt.

The Straßburger Straße stop shortly before its opening, 1963

Opening of the Wandsbek Markt stop, 1962

Branches to the west and east

In 1960, planning began for the next major subway project: the cross connection between Billstedt and Stellingen, with work on both branches being carried out simultaneously and the construction challenge lying in the inner-city central section. Although a free route was available from Berliner Tor to Billstedt and it was possible to build in an open manner, contrary to initial plans the line had to run in a tunnel due to the high groundwater level. Only the last section between Legienstrasse and Billstedt was in a cut. On January 2, 1967, the line went into operation as far as Horner Rennbahn, and Legienstraße was completed on September 24. The Billstedt stop was opened on September 28, 1969, and then Merkenstrasse as the temporary terminus on May 31, 1970. It was not until September 29, 1990 that the two stops Steinfurther Allee and Mümmelmannsberg opened.

Work on the Stellinger section began on May 1, 1964, with the discontinuation of subway service between Schlump and Hellkamp and the demolition of the previous terminus. This was followed by fundamental renovation and reconstruction work at the Christuskirche, Emilienstraße and Osterstraße stops. The opening of the Lutterothstrasse stop on May 30, 1965 was followed by the Hagenbecks Tierpark terminus on October 30, 1966.

This meant that the growth area of Stellingen and populous Billstedt were connected to the subway network. However, this was not to be the end of the story, as the goal was to be able to reach the city center directly.