INTRO: After many years of delay, the long-planned cross-city tunnel in Leipzig is finally under construction. The 4·3 km twin bores serving four stations will be used by S-Bahn and regional express services. Ralf Roman Rossberg reports
IT HAS BEEN a long wait. But now, after more than a century of delays, the rail network in Leipzig is to be rebuilt to meet the city’s needs. At last, Leipzig is to enjoy the benefits of an extensive S-Bahn network, at the heart of which will be a cross-city tunnel.
Leipzig is one of Germany’s most important railway centres. It is also one of the oldest, with Germany’s first inter-city railway opening between Leipzig and Dresden in 1839. The 19th century railway infrastructure has long been in need of modernisation, but until recently every plan to expand and develop the network seemed doomed to fall foul of political obstacles.
The city is located on several important long-distance main lines. It is an important intermediate calling point for trains between Berlin and München, and is also served by trains in the international corridor linking Amsterdam and Praha via Hannover and Dresden.
In common with many other European cities, Leipzig once had separate stations serving different railways. From 1915, routes to the west, north and east were reconstructed to converge at the Hauptbahnhof, leaving only routes from the south serving the Bayerische Bahnhof in the southern part of the city.
Today these two termini are still extant, with the Hauptbahnhof lying north of the city centre; it is, incidentally, Europe’s largest terminal station. Trains ceased to use the Bayerische Bahnhof in 2002, although the main buildings remain intact.
Now the two stations are to be linked by a cross-city tunnel similar to that built to join the Hauptbahnhof and Ostbahnhof in München before the Olympic Games in 1972. Whereas the München tunnel is used exclusively by S-Bahn trains, the Leipzig tunnel will be shared by Regional Express routes. Later, long-distance trains between Berlin and München may also be routed through it.
Long-standing project
The first scheme to build a cross-city link in Leipzig dates back to 1893. At that time a four-track alignment on a viaduct was envisaged, but when the main station was built in 1911, Siemens & Halske received a contract to construct a U-Bahn line below the city using electric traction. There was no intention for the U-Bahn to carry long-distance traffic, but in the event the line was never built. In 1929 an ambitious urban development plan was drawn up, and this stressed the need for long-distance trains to run through the heart of the city. But this too came to nothing.
The project was discussed again in the 1960s when Leipzig was part of East Germany, but this time the emphasis was on developing local traffic. When the city’s first S-Bahn service was eventually launched in 1969, it had to make do almost entirely with existing tracks, the only new section being a line to Miltitzer Allee, serving the development area in Grünau to the west.
With Germany’s reunification, the chances of building the cross-city tunnel improved, although the costs were put at more than DM1bn or €570m.
After many more setbacks, contracts for the project were finally signed between the Federal Transport Ministry, the Land of Sachsen, the City of Leipzig and DB AG on May 23 2003. A ceremony to mark the start of work was held on July 9 2003, and the target now is to complete the tunnel within six years.
Alignment
The tracks will run in two single-track bores with central platforms at the intermediate stations. The 4·3 km alignment includes four stations: Hauptbahnhof, Markt, Wilhelm-Leuschner-Platz and Bayerischer Bahnhof. The route begins in the northern approaches to the Hauptbahnhof, dropping down to serve new platforms beneath existing platforms 3 and 4 on the western side. The alignment then continues below Ringstra§e towards the city centre.
The underground platforms at Hauptbahnhof will be 215m long, but they will be designed for subsequent lengthening to 400m for use by long-distance trains. Exits will provide easy access to the main concourse and to the station forecourt, ensuring that passengers have only a short distance to walk to reach the city or to interchange to trams or buses.
From Markt, near the town hall in the geographical centre of the city, all important locations in the inner city are within easy reach on foot. Two exits will lead directly from the platforms, with a glass lift tower at the northern end and steps at the south end that will serve a mezzanine area; the southern exit will continue through the underground entrance of the city’s former trade fair building, which is a listed structure.
At Wilhelm-Leuschner-Platz there will be interchange to tram services. An exit at each end of the station will lead to an intermediate floor, from where passengers can reach tram stops without having to cross the street.
The S-Bahn station at Bayerischer Bahnhof will also be underground, although the historic station building with its famous portico will be retained. Passengers will enjoy easy interchange to tram services with only a short walk required. Immediately beyond the station, the tunnel alignment regains the surface.
Because of the deep foundations of buildings along the route, the tunnel is being dug between 17 and 22m below the surface. Steepest grade will be 4%, with the station areas limited to 2·5%. Minimum curve radius will be 500m, and the trains will run at up to 80 km/h.
Shield tunnelling methods are required to cut the 9m diameter bores between the stations, but the station boxes are being constructed using cut-and-cover. Special measures are being taken to minimise disturbance on the surface; for example, the excavation at Markt will be covered over for part of the construction period. The station here has been designed with lavish use of glass so that natural light can penetrate down to platform level.
Routes and services
S-Bahn and Regional Express trains will call at all stations, but when long-distance trains eventually use the line, they will stop only at Hauptbahnhof.
The current plans envisage four S-Bahn and three Regional Express services using the tunnel:
S1: Miltitzer Allee - St
