The major underground interchange under construction at Potsdamer Platz will cope with 250 000 people a day when the surrounding redevelopment is complete. Of these, 60 000 will use the regional trains on the north/south link. This central hub station is being built in a huge 250 x 50 x 20m deep cut+cover box. Inside this outer box, the 12m high station structure itself is built as a free standing, waterproofed structure. As with all structures built underground in Berlin, flotation is a problem, so uplift of 1.8 bar on the station box is countered using 25m long ground anchors.
Connections have had to be provid-ed to the existing nearby S-Bahn railway station. In addition, provision for a new metro line – U3 – which is planned to run from Alexander Platz in the east to the Tiergarten area and eventually on to Tegel Airport has already been made in the design. An elevated ‘bridge’ has been constructed to carry the metro extension above the rail platforms with the secondary role of acting as a prop to the box structure. The two central platforms are 230m long but it is not planned that inter-city trains will stop at this station at present.
The station is scheduled for completion in early 2000.
Lehrter Station is a huge develop-ment north of the River Spree, facing the new Chancellery building and the Reichstag, and is costing $523m. It is the key to the new link and will be the last element to be completed because of design changes which have included the late addition of a 900 space car park with links to the new B96 road tunnel. This station will not now be ready until 2005.
Lehrter Station provides an inter-change between east-west and north-south local, regional and intercity rail lines, metro and tram routes. These, together with retail developments, are housed in a four storey structure, two levels of which are below ground.