The Bjørvika Tunnel, Oslo, Norway

DEVI supported the first immersed tunnel in Norway

The Bjørvika Tunnel is a motorway immersed on European Route E18 in the city center of Oslo. The tunnel links Festning tunnel in Oslo west with Ekeberg tunnel in Oslo east. The completed tunnel has an unbroken length of six kilometers.

The immersed part of the tunnel is made up of six elements. Each element is 112.5 meters long, 28–43 meters wide and 10 meters high. The immersed tunnel consists of two tubes, with three lanes in each direction. The tunnel is 1,100 meters long, 675 meters of which are below sea level. The Bjørvika Tunnel is part of the Opera Tunnel complex, which is the interconnected system of tunnels between Ryen and Filipstad.

The Bjørvika Tunnel was opened in September 2010 as the first immersed tunnel in Norway. During its construction, DEVI electrical heating solutions were used to harden the concrete in roof and walls in the immersed part of the tunnel. A uniform concrete may cause a problem, especially during the Scandinavian winter. DEVI electrical cables were chosen to make sure that hardening process unfolded properly.

DEVI electrical solutions are used to maintain a normal concrete hardening process during winter where temperatures often fall below the freezing point to not delayed that building process due to the weather conditions.

Project overview
  • 1 100 meters of tunnels
  • 675 meters of which is immersed
The DEVIreg™ 330 is an electronic thermostat to be installed in electric cabinets with DIN rail attachment. Used primarily for controlling a lower temperature range as by frost protection. The thermostat must be installed via an all-pole disconnection switch and has a LED indicating the current mode (heating, standby or fault). To measure and control the desired temperature a wire sensor or an outdoor air sensor must be used. The temperature setting can be adjusted with a scale from -10°C to +10°C.
Heating cables
DEVIflex™ 30T is an extremely high-quality, 360° fully screened twin conductor cable with a tough outer sheath (non UV stable). It has a round profile and robust construction which ensures a fast, simple and safe installation. It is designed for concrete hardening only.