Bekkelaget Tunnel

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Bekkelaget Tunnel is a 578-meter-long railway tunnel on the Østfold Line near Bekkelaget in Oslo, Norway. It carries two electrified tracks (standard gauge) and is 9.55 meters wide. The line through the tunnel climbs slightly, with a gradient of 1.0% from north to south. The northern end is about 3.08 kilometers from Oslo Central Station (Oslo S).

Reason for building
In 1953 a landslide damaged both the railway and the Mosseveien road along Bekkelaget. To free space for the road, planners decided to move the railway into a tunnel. Construction began on 14 April 1955, and the tunnel was opened in September 1958.

New station and bypass
Bekkelaget Station was located on the section that would be bypassed by the new tunnel. A new Bekkelaget Station was built at the tunnel’s southern entrance and opened with the tunnel. The old station and its track were abandoned, and the new station operated until 29 May 1983.

Construction details
The tunnel runs through the mountainside at Bekkelaget and has a minimum curve radius of 400 meters. The Østfold Line itself opened in 1879. After the landslide, an early temporary solution blasted a 300-meter shelf into the hillside to move the tracks. The government approved the tunnel project on 24 December 1954. Breakthrough occurred on 8 March 1956, and concrete walls were completed by November 1957. A road bridge at the northern entrance allowed Mosseveien to pass over. The tunnel and the new station opened in September 1958. The total cost was about 7.4 million kroner, with NSB contributing 950,000 kroner.