Denmark and Sweden are two countries separated by the Baltic Sea, and they are joined by a bridge-tunnel that runs from the Danish capital, Copenhagen, to the Swedish city of Malmö. But it is not just any bridge, but a marvel of engineering, a hybrid that is half bridge and half tunnel that leaves you open-mouthed.
This is the Oresund bridge-tunnel, the incredible work that unites Sweden with Denmark and the rest of Europe
The decision to create such a peculiar work was taken due to a combination of circumstances. To build a tunnel for the 16 kilometers that separate the two cities would have been very expensive, and building a single bridge also had its drawbacks.
Therefore, it was neither one nor the other, but both at the same time. A tunnel – island – bridge that achieves a spectacular effect when we start from the Swedish coast, as it looks like a bridge engulfed by the sea.
The tunnel itself has a length of 4,050 meters, and starts from the Danish area until it reaches the artificial peninsula of Kastrup. There it comes to the surface and is replaced by a 7,845-meter bridge. It is in fact the longest mixed bridge (for vehicles and railroads) in Europe, whose highest pillar measures 204 meters, has three spans, and weighs a total of 82,000 tons.
A single ingenious solution to several problems
The bridge is strategically located in the Öresund Strait. It is on a tongue of sea between Denmark and Sweden, where the Baltic Sea connects with the North Sea and the rest of the Atlantic Ocean.
It is also one of the points where the two countries are closest to each other.
It so happened that at the turn of the last century the cities of Copenhagen and Malmö had complementary needs. The Danish capital had affordable housing, while the Swedish capital had more jobs.
This, together with the opening of Europe’s borders, made the governments of the two countries decide to link them so that they would no longer depend solely on ferry service.
But it was not going to be that simple. For one thing, the strait is a strategic passage for ships, so they had to build a bridge high enough for them to pass. And this was a problem, because on the Danish coast is the Copenhagen-Kastru Airport, and such a height could be dangerous for airplanes.
The second solution could have been to build a tunnel, but the 16 kilometers separating the two cities was too high a budget. In the end they decided to do both at the same time. On the Danish side it would be a tunnel so that there would be no problems for the planes, and on the Swedish side a bridge so that the work would not cost too much.
The project began in 1991, and dragged on for nine years until it was opened to the public in 2000. The tunnel segments were towed from the manufacturing site and positioned using GPS technology, then submerged and placed on a level base on the prepared seabed.
The central towers of the bridge were placed by the world’s largest floating crane, and are designed so that the bridge will not be destroyed even if a plane crashes into them. The bridge is composed of two spans connected by a third central cable-stayed span. The span of this, the space between two consecutive girders, is one of the longest in the world at 490 meters. At this point the bridge rises 57 meters above sea level and is supported by piers up to 204 meters high.
