The technically demanding renovation of the Kulosaari Metro Bridge

Kreate is carrying out repair works on the Kulosaari metro bridge on a key section of the Helsinki metro line. Additional foundation supports are being installed on the 420-metre-long bridge over the waterway, located between Kalasatama and Kulosaari stations, and repairs are being carried out on, amongst other things, the waterproofing, the superstructure and the surface structures. The project is made challenging by the limited working space beneath the bridge, the dense urban environment and the need to extend the existing underwater structures. The contract commissioned by Helsinki City Transport is Kreate’s third contract on the metro line in 2026.

The Kulosaari metro bridge is a technically very challenging repair project, located on the Helsinki metro line between Kalasatama and Kulosaari stations. The western end of the bridge is connected to the Redi shopping centre, and almost the entire 420-metre-long bridge spans Vanhankaupunginselkä.

Currently, the metro bridge is supported by the adjacent Kulosaari road bridge. As part of the renovation, Kreate is constructing additional supports on the existing foundations, allowing the metro bridge to become structurally independent in the future. This will enable the horizontal supports connected to the road bridge to be removed and ensure uninterrupted metro traffic when the road bridge renovation begins in 2028.

One of the most demanding aspects of the project is extending and widening the existing underwater foundations. The work requires connecting new and existing structures in a watertight manner and constructing new support elements in extremely confined conditions. To facilitate these operations, Kreate is building a temporary work bridge approximately 250 metres long beneath the structure.

A significant portion of the work is being carried out under the bridge, where space is exceptionally limited. This places high demands on equipment selection, engineering design, and construction sequencing. Protective casings will be built around the existing structures, allowing the old and new foundations to be connected using dry construction methods.

The project also includes specialised foundation work involving bored piles installed beneath the existing bridge. These works require careful planning and precise execution. KFS Finland, part of the Kreate Group, is carrying out the piling operations in approximately four-metre sections, welding the piles together on site as the work progresses.

The client is Helsinki City Transport Ltd. The project will run from October 2026 to March 2028 and will be executed as a turnkey contract. The contract value recognised in Kreate’s third-quarter order book is €8.2 million.