Last segment of Stockholm rail tunnel submerged

The final 100 metre portion of the Söderström tunnel has been lowered into place in the Mälaren river.

By submerging the third 20,000 tonne section on August 6, contractors completed a key phase in the construction of the 400 metre underwater tunnel which will link Södermälarstrand and Riddarholmen in the centre of Stockholm.

Known as the Söderström tunnel, the project is part of the 6 kilometre Citybanans line.


“This is a milestone for the City Line project,” said project manager Kjell-Åke Averstad, with the first two sections having been lowered into place earlier in the year.

For each length of tunnel, water had to be pumped inside to allow the structure to gradually sink into place over the course of 24 hours.

With the segments together, the partitions will now be removed and the tunnel cast together ahead of the line’s first trains in 2017.





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