The Øresund bridge

Mariano A. Davies examines the Øresund Bridge as a remarkable fusion of engineering

innovation, ecological sensitivity, and cross-border collaboration in Scandinavia.

Photographs: Øresundsbron FB PG

Text: Mariano Anthony Davies

The bridge

Four pylons and 80 pairs of stay cables create the iconic silhouette of Øresundsbron over the Øresund. The bridge is a 7.845-metre combined railway and motorway bridge with a double-track railway on the lower deck and a four-lane motorway with shoulders on the upper deck.

It is divided into three sections with two approach bridges supported by piers and a high bridge suspended by pylons with stay cables over the Flintrännan navigation channel.

The high bridge features a 490-meter free span, making it one of the world's longest cable-stayed bridges for both motorway and railway. The west approach bridge (3.014 metres) stretches from the artificial island of Peberholm to the 1.092-metre-high bridge. On the eastern side, the 3.739-metre east approach bridge connects with Lernacken on the Swedish side.

The stay cables are arranged in an even-angled pattern for stability and are located outside the roadway for protection against collisions. To prevent oscillations in certain wind conditions, vibration dampers are installed. The pylons (203,5 metres tall) taper upwards, giving an appearance of strength and balance.

Peberholm

Peberholm is the green island in the middle of Øresund, spanning 130 hectares, and was established between 1995 and 1999 - using dredging material (approximately 9 million m³) from the construction of the tunnel trench. Its name refers to Saltholm, the natural neighbouring island to the north (“salt and pepper”).

Peberholm was created as part of the Øresund Bridge, serving as a transition point between the bridge and the tunnel. The island was constructed to enable the shift of traffic from the bridge—where train and car traffic operate on two levels—to the tunnel portal on the island's western side, where traffic enters the Øresund Tunnel on a single level side by side.

The island is surrounded by stone embankments (approximately 2 million m³). No landfill or soil from the mainland was added (just from the tunnel), and nothing was planted by human hands. The island was left barren, allowing all species to migrate naturally from either Denmark or Sweden. Since Peberholm's establishment, nature has been left to evolve freely, making it an exciting natural experiment that has developed rich biodiversity. The island has transformed from a barren area into the green island with an impressive and unique variety of flora and fauna.

Peberholm has been a “Natura 2000” site since 2000, and its nature is considered particularly valuable from a European perspective. Øresund Bridge therefore strives to preserve its strong biodiversity.

The Øresundsbro Consortium's original strategy of allowing nature to develop without human intervention proved highly successful. Within just a few years, the barren area became home to an impressive variety of plant and animal life. The number of plant species found on Peberholm is now estimated to be around 600 with approximately 30 bird species nesting there annually.

The tunnel

The tunnel is essential to avoid disruption to air traffic to and from Copenhagen Airport and to ensure that large ships can pass through the Øresund Strait. It is equipped with modern technology for ventilation, lighting and safety, making it a secure and reliable connection for both car and train traffic.

The Öresund Tunnel was built from 20 tunnel elements that were manufactured at a tunnel factory in Denmark and then submerged and placed in extension of each other in a dredged trench on the seabed under the Drogden shipping channel. Each tunnel element is 176 metres long, 9 metres high, 40 metres wide and weighs 55.000 tons. The 3.510-metre-long immersed tunnel is complemented by two portal buildings, each 270 metres long.

The approaches to the two motorway tubes have light filters in the ceiling to provide drivers with a smooth transition between daylight and the electric light in the tunnel. Every 88 metres, there are 1,2-metre-wide escape doors from the road tunnels to the service and escape tube. Furthermore, each motorway tube has a total of 80 jet fans. Their main function is to expel smoke and heat in the event of a fire, but also to keep the air clean in all situations.

The toll for this crossing is only collected on the Swedish side. The cost of the project in 2000 was DKK 30 billion (approx. DKK 53,2 billion in 2025) and took five years to complete. In 2024, the annual profits were the highest ever at DKK 1,6 billion.