Slussen bridge: Stockholm centrepiece

Located in central Stockholm, every day 400,000 people pass through Slussen on public transport, and that number is expected to double by 2030. Slussen is situated between the southern part of Central Stockholm, Södermalm, and Old town. It consists of bridges over the locks that connects the lake of Mälaren with the Baltic sea.

Slussen was originally built 80 years ago and needed to be upgraded to be able to handle the increasing number of people who pass by daily. As part of the expansion, it was decided to build a new bridge between two of Stockholm’s neighbourhoods, Södermalm and Gamla Stan.

Ramboll has worked with design, drawings and calculations for the steel superstructure for the new bridge.

For almost two years, Ramboll's bridge team worked on the design of the new bridge that will carry car and bus traffic, pedestrians and cyclists between two of Stockholm’s neighbourhoods, Södermalm and Gamla Stan.

The City of Stockholm manages the construction and repair of the new Slussen, and Skanska is one of the contractors.

Large variations in cross-section heights

The new bridge is as big as a football field and the steel alone weighs 3,400 tonnes.

Commissioned by Skanska and Stockholm municipality, for several years Ramboll has been planning the bridge which is to become a centrepiece in the new Slussen. The work on the bridge has taken almost five years, covering design, calculations, workshop drawings and additional project planning, including transportation and construction. During the whole project Slussen remained functioning as an important hub of communications as well as meeting place.

140 metres long and 45 metres wide, the bridge has lanes for walking, cycling and cars and buses. It extends from Skeppsbrokajen in Gamla Stan to Katarina Lift on Södermalm and has a slip road to Stadgårdsleden. To make this possible, the height of the bridge on the Södermalm-side is about eight metres and about one metre tall on the Gamla Stan side. The geometry of the bridge is rather special in appearance with varying inclination of the sides of the bridge, making each cross-section unique.

“The biggest challenge in our work was that the bridge has a large variation in cross-section height and a varying cross-section geometry in general. In addition, there is much more to the construction than meets the eye. The bridge is as big as a football field and weighs 3,500 tons,” says Victor Vestman, bridge designer at Ramboll.

The project is the largest that Ramboll’s Swedish bridge team has worked on so far. Work on the main bridge started in 2015 and continued until the summer of 2017. The new Slussen is expected to be completed in 2025 and the bridge was in place in the spring of 2020.