Undersea tunnels in Norway

The project included renewal of electrical equipment, lighting, telecommunications equipment, traffic controls and more in undersea tunnels.

About this Project

Statens Vegvesen, region north, Norway


Tromsø and Tomasjord, Norway


The project's objective

The Tromsøysund tunnel has two undersee tunnels, 3,500 m and 3,386 m in length, that are located between Breivika in Tromsø and Tomasjord in Norway. Between the tunnels are 15 escape tunnels. The tunnel was opened in 1994.

The project involved a redesign of all electrical, lighting, emergency, control, monitoring and communications systems in the tunnels. In addition, the entire cable routes had to be renewed, the equipment rooms were expanded and rebuilt, and a new pump house was built.

The emergency power generator of the tunnel was removed, and instead the tunnel was equipped with a double power supply feeding. A new 11/22 kV transformer was installed, to adjust the high voltage system of the tunnel to a 11 kV power supply from Breivika.

All electrical and control equipment in the tunnel was renewed. Lighting of the tunnel was refurbished and increased greatly. An emergency lighting was installed in the ceiling and on the walls of the tunnel.

Camera surveillance system is in the tunnel with a radar detection, which gives alarms to the control room for abnormal incidents in the tunnel.

Traffic control system was installed with traffic booms and blinking lights, where it is possible to control the traffic in the tunnel, turn it around, allow traffic only on one lane or close it completely.

EFLA's role

  • Consultation
  • Design of electric, control, lighting and telecommunication systems in tunnels
  • Design of concrete technical buildings and pump house
  • Fire and security