At the same time as the rail link, a new road tunnel and an extension to the U-Bahn (metro) line U5 into east Berlin are being constructed in the same vicinity.
The metro extension extends from the Brandenburg Gate and runs to Reichstag and Lehrter stations. Of this extension, 489m is in twin bored tunnel being excavated by a 6m diameter Herrenknecht machine originally used on the Cairo Metro. Contractor Walter Bau reports that tunnelling is now complete and that all construction works will be achieved by March 2000. The line will later be extended to Alexander platz.
The B96 road tunnel follows the existing surface route of the road through the Tiergarten. Of cut+cover concrete box construction, it will have two tubes, each with two lanes. Once they are completed, traffic will be removed from the park.
In the Spreebogen area, south of Lehrter Station, the B96 road, the four lines of the north-south railway link and the U5 tunnels run parallel to each other and pass under the River Spree in a submerged concrete box 100m wide and only 1m below the river bed. This was constructed in open cut, with the river diverted from its course during the works. Once under the river, the tunnels enter a major open cut excavation in front of the Reichstag.
The contractors on all three projects were compelled to come together on this 800m section and treat it as one project, working together in the highly congested area.
At the time of the visit, the section between Lehrter Station and the Reichstag pit was complete except for a 200m section marking the diverted route of the Spree.
