The Norwegian National Rail Administration has nominated a consortium formed by ACCIONA and Ghella to build the longest railway tunnel in Scandinavia - twin tunnels 20 km long that will link Oslo to the town of Ski.

The €1 billion project will be ACCIONA’s first in Norway.

ACCIONA, a global infrastructure and renewable energy group, in partnership with Ghella of Italy, have been named preferred bidders by the Norwegian National Rail Administration to design and build the 20km twin-tunnels of the Follo Line Project.

The twin railway tunnels, of 8.75 metres in diameter, will link the cities of Oslo and Ski to form the core part of the InterCity development southwards from the Norwegian capital.

The contract, valued at NOK 8.7 billion, or more than €1 billion, is the largest transport infrastructure contract in Norway, and also ACCIONA’s first in the country. The contract is scheduled to be signed before Easter and the work will commence immediately thereafter.

This is the second, and largest, of four EPC contracts for the Follo Line Project, currently the largest infrastructure project in Norway. The mega project is executed by the Norwegian National Rail Administration on behalf of the Ministry of Transport and Communications.

The Follo Line twin tunnels have been designed for high-speed trains of up to 250km/hour, and, at 20km in length, will be the longest railway tunnels in Norway.

The construction of the twin tunnels will involve the simultaneous deployment of four tunnel boring machines. Two machines will drill north towards Oslo and two machines will drill southward toward Ski. The tunnels will be connected by galleries at 500-meter intervals.

In addition, the tunnel works will include an underground rescue area, the blasting of larges assembly halls for the tunnel boring machines, rescue tunnels, an escape tunnel of 2.7km in length, and two transport tunnels each of 400m in length. The joint-venture will also perform all the railway installations, with the exception of the signal system.

The ACCIONA-led joint-venture was nominated following an international bidding process that attracted the interest of some of the world’s leading contractors.

ACCIONA’s Engineering division was named the lead engineering consultant of the project during the bidding phase, and will be responsible for the construction design of the tunnel works. It will also provide technical assistance for the project’s key stages, and be responsible for conducting the final tests before the project is delivered to the Norwegian National Railway Authority.

ACCIONA brings its extensive international experience in high-speed rail and tunneling to the Follo Line Project. In addition to building a large part of Spain’s high-speed rail network, it also built the twin tunnels of Bologna’s high-speed rail station in Italy, and is currently building the twin tunnels of the Legacy Way in Brisbane, Australia, where ACCIONA’s TBMs have broken the international daily, weekly and monthly speed records for tunneling machines.