Rostock Warnow Tunnel

After 1989, motorisation began an upward spiral both on the commercial and private sector in the east of Germany. Heavy supra-regional source and target traffic as well as through traffic in an east-west direction caused gridlock Situations on Rostock's main traffic arteries on a regular basis. Something had to be done to remedy the considerable time losses and the increasing nuisance caused by dust, fumes and noise. Pertinent studies, which also took future traffic frequencies into consideration pointed to just how imperative it was to set up a northern Warnow crossing. When the Port of Rostock was built and became operational in 1960 to the east of the Lower Warnow and new residential areas were created in the northwest of the city, it was also intended to construct a permanent Warnow crossing indeed it was an integral part of urban development planning. The required land for the project in fact had been reserved since 1974 and no buildings were allowed to be set up on it. The route alignment and the preferred tunnel solution were included in the plans for port development and the Warnow Park at Schmarl. The route is located in Weichsel, Saale and Fläming glacial deposits. These are thick glacial marls with intruding glacifluvial sediments, which largely consist of sands, younger holocene layers are to be found above the glacial deposits; these are made up of silty sands and organic sediments (peat, limnic muds). The base of the pleistocene deposits is located roughly 50 m beneath the surface. As from this depth there are tertiary deposits. At the start of 2000, work on building a tunnel using the immersed tube method commenced. The subsurface was unsuitable for a bored tunnel, which would have entailed carrying out the project at a major depth. The required 6 tunnel elements were prefabricated in the construction dock. Towards this end, 2 elements were produced simultaneously, floated out and temporarily stored. One element weighs no less than 20,000 t and is 120 m long. The outer wall thickness amounts to 0.90 m, the ceiling thickness 1.05 m, the base is 1.20 m thick and the side spurs 0.80 m thick. The Warnow was dredged to produce the tunnel route. It has a longitudinal gradient of 4% and a transverse gradient of 3%. Supporting foundations were installed. The elements are sealed against one another by means of a polymer seal in an omega profile and covered with gravel. Rocks protect the tunnel against the impact of ships and anchors along the shipping channel. The Warnow Tunnel has 2 lanes per direction of travel, each 3.50 m wide with emergency footpaths that are 1.05 m wide at both sides. The clearance height amounts to 4.50 m. The 2 tunnel tubes are separated by a 50 cm thick central partition. RABT 2003 specifications, which were being revised at the time, were taken into consideration during the construction phase. Tolls are levied for travelling through the Warnow Tunnel, which is Germany's pilot project for PPP.

Country: Germany
Region: Germany, Mecklenburg-Vorpommern
Tunnel utilization: Traffic
Type of utilization: Road tunnel
Client: Hanseatic City of Rostock
Consulting Engineer: Bung Beratende Ingenieure, IMM Prof. Dr.-lng. B. MaidI- Dipl.-lng. R. MaidI
Test engineer: Prof. Duddek und Partner GmbH
Construction monitoring: WRI (Warnowquerung Rostock lngenieurconsult)
Contractor: Bouygues Travaux Public S.A.
Main construction method: Open
Type of excavation: Immersion/Sinking
No. of tubes: 2
Tunnel total length: 4 km, 790 m tunnel and 4 bridges
Cross-section: 160 m²
Contract Volume: approx. € 156 million
Construction start/end: March 2000 to September 2003
Opening: September 12th, 2003