The Öresund Bridge, the much desired link between Sweden and Denmark, was completed in 2000. Skanska was part of the Sundlink Contractors’ consortium, along with the German company Hochtief, as well as Højgaard & Schultz and Monberg & Thorsen from Denmark. The four companies belonged to the bridge-building elite and jointly created a bridge that generated major worldwide attention.
The building project has been described as a gigantic puzzle, which was built piece by piece. It was precision work that required satellite navigation, engineering skills and the expertise of craftsmen.
In order to cause as little disruption as possible to shipping activities, the eastern connecting bridge and the high-level bridge were constructed first. When work was in the final phase, the western connecting bridge was built.
The Öresund Bridge comprises three sections – two connecting bridges and a high-level bridge. The bridge was built in two stories, one roadway and a lower level for the railway. The high-level bridge comprises a diagonal-cable bridge, the longest in the world, with both railway and motorway. The two bridge towers are 203.5 meters high, thus making the Öresund Bridge Sweden’s highest structure. The main span is 490 meters long and the vertical clearance is 57 meters.
The focal point for the complicated bridge construction was the head office in Norra Hamnen in Malmö. This was the headquarters. We also built our own concrete station here and a harbor that was specially adapted for the automatic pontoon crane, Svanen, which transported caissons and other materials to the bridge line.
Caissons (bridge base), pillars for the connecting bridges, the roadway for the high-level bridge and the trench for the railway tracks for the connecting bridges were manufactured at the concrete station. The heaviest caisson weighed 4,700 tons. Concrete corresponding to 128 Olympic-size swimming pools were used. We monitored the concrete in a special laboratory to ensure top-class sustainability.
The bridge project commenced with the installation of the abutments at Lernacken in Malmö, and at Peberholm, the artificial island in the middle of Öresund. At Peberholm, a 560-meter viaduct was also constructed, which is connected to the abutment on the Danish side.
After that, it was time for the bridge line, meaning the stretch through the sea where the bridge will be located. The sea floor was dredged and prepared for the caissons, which will bear the pillars and pylons. The dredged masses, 240,000 cubic meters, were used as filling in Norra Hamnen and to build Peberholm.
When the sea floor was prepared, the caissons for the connecting bridges were transported to the bridge line from Norra Hamnen using the pontoon crane, Svanen. The gigantic pontoon crane could lift 8,700 tons and was a floating workplace.
Precision requiring satellite navigation
The pylon caissons for the high-level bridge weighed 20,000 tons and were transported to the bridge line using a specially built pontoon catamaran. Since the pylon caissons had to be placed in exactly the right location, we used the satellite navigation system GPS, and surveillance from divers and underwater cameras; an enormous operation that had to be executed with precision. The caissons were finally cast to the bottom.
The pylons themselves (high-level bridge pillars) were cast at sea. They were built at a speed of four meters in eight days and the final height is an impressive 203.5 meters. Sweden’s highest structure!
The high-level bridge sections rest on two cross bars but are primarily born by 80 pairs of cables. A total of 25 kilometers of cables were used.
Alternating weather at sea
A total of 400 individuals were involved in offshore work. The various shifts went out to the bridge line from Limhamn, where there was also a reinforcement station for pylons and spare-parts storage.
Offshore working conditions were periodically fantastic, with brilliant sunshine and glittering waves, changing suddenly in a second to harsh winds and strong sea currents. The various bridge sections were produced at several different locations – from Cadiz in Spain to Karlskrona in Sweden.
Tests, controls and painting
Numerous tests and controls were required for the major bridge construction. Wind-tunnel tests, erosion tests and test casting were conducted. Concrete quality, steel structures and welding were examined continuously.
The Öresund Bridge was painted using several layers of primer and two layers of intermediate paint. A total of 260,000 liters of paint were used.
The project in figures
• 51 caissons (bridge bases) were cast. The height varied between 12 and 20 meters. The heaviest weighed 4,700 tons, the lightest 2,500 tons.
• 51 pillars were cast, on which the connecting bridges rested. The height varied between 10 and 51 meters. The weight was between 800 and 3,500 tons.
• 320,000 tons of concrete were used, corresponding to 128 Olympic-size swimming pools.
• For one pylon caisson, holes were excavated corresponding to 38x40 meters on the sea floor. For the smaller caissons, holes corresponding to 20x20 meters and 20x26 meters were dug. The holes were 6-10 meters deep.
• The pylons on the high-level bridge are 203.5 meters – Sweden’s highest structure.
• The pylon caissons weighed 20,000 tons.
• The main span on the high-level bridge is 490 meters long, vertical clearance is 57 meters.
• 25 kilometers of cable was used for the high-level bridge. 80 pairs of cables were installed and each individual cable has a breaking strength of 2,000 tons.
• 240,000 cubic meters of dredged masses were used as filling in Norra Hamnen and for building Peberholm.
• The heaviest section weighed 6,900 tons. Together with the pontoon Svanen’s lifting tool of 1,800 tons, lifting ability of 8,700 tons was used.
• A cable comprises 70 sub-cables.
• The bridge was painted using 260,000 liters of paint.