A new connection in the heart of Berlin

Rotes Rathaus station (designed by Collignon Architektur).

An inspection run through the Museumsinsel station (designed by Max Dudler Architekten).

Creating the tunnel expansion with the protection of ground freezing.

The Rotes Rathaus station consists of three levels.

The construction pit in front of the Rotes Rathaus.

After ten years of planning and construction time, the new section of Berlin’s U5 subway line finally opened on December 4. This long-awaited link closes the gap between the Alexanderplatz and Brandenburger Tor stations via a new 2.2-kilometer-long route that includes three stations boasting expressive and sophisticated architecture.

WTM Engineers was commissioned with inspecting the two structurally complex stations at Rotes Rathaus and Museumsinsel respectively. Inspection engineers Dr. Scholz and Dr. Morgen were also responsible for inspecting the track-switching system, the starting shaft for the tunnel drive, the Alexanderplatz holding depot, and the carriageway trough (mass-spring system) along the 2.2-kilometer route.

Particularly challenging elements of construction were the transitions and widenings between the two-platform route tunnel and the attached buildings. These were laid in the wet and sandy ground of Berlin’s Mitte district using the new Austrian tunnelling method (NATM), among others, with the protection of ground freezing.