Tanum Tunnel, Bærum

Tanum Tunnel is 3,590-meter-long double-track railway tunnel on the Asker Line, between Jong in Bærum and Åstad in Asker, Norway. It was built as part of the first stage of the Asker Line, between Asker and Sandvika; construction started in February 2002 and the tunnel opened on 27 August 2005. The tunnel was built by AF Gruppen for the Norwegian National Rail Administration. Most of the tunneling was conducted using the drilling and blasting method, although the easternmost 800 meters were built using the cut-and-cover method. After the tunnel opened, there have been problems with leaks damaging the superstructure. The tunnel has double track, is electrified and allows for a maximum speed of 160 kilometers per hour. The cost to build the tunnel, excluding the superstructure, was 370 million Norwegian krone. The tunnel will accelerate intercity and regional traffic west of Oslo and free up capacity for the Oslo Commuter Rail on the Drammen Line. ()