They will be the longest railway tunnels in Scandinavia, part of the Follo Line project, the biggest transport infrastructure ever built in Norway.
Twin tunnels, each 19.5 km long with an internal diameter of 8.8 meters, will connect the cities of Oslo and Ski, establishing the central axis of the intercity development to the south of the Norwegian capital.
Designed for trains running at 250 kmph, carrying passengers between the two cities, both tunnels have been drilled by four huge double-shield Tunnel Boring Machines (TBMs), named Anna de Kloppa, Magda Flåtestad, Queen Euphemia and Queen Elisiv in honor of four of the country’s bravest and most enterprising women.
The TBMs, each 150 meters long and weighing 2,400 tons, began hewing the tunnels out of rock in the Ekeberg hills, Åsland, at the halfway point, where installations were built to support the project’s keystone and concrete manufacturing plants.
The challenging job of drilling the tunnels also involved blasting caves for the TBMs, rescue tunnels (including a 2.7-km-long escape tunnel) and two 420-meter-long transport tunnels. The consortium, formed by ACCIONA and Ghella, will also construct all the project’s railway installations except the signaling systems. Resilient transport infrastructure bringing well-being and progress to Norwegian society.
Connect the cities of Oslo and Ski by rail, forming a central axis for interurban development south of the Norwegian capital.
Drive the economic development of the region and connect the inhabitants of Oslo and Ski.
Once complete, the two 19.5km rail tunnels will be the longest in Scandinavia.