Tunnel TBM contract nominated

Tunnel TBM contract nominated

Mar 4, 2015  | Civil engineering 

Tunnel TBM contract nominated
(Photo by: I, Besse)

The Norwegian National Rail Administration has nominated a Joint Venture consisting of Acciona Infraestructuras S.A. and Ghella S.p.A. for the tunnel TBM contract for the Follo Line Project. This is the largest railway contract to date in Norway.

This Joint Venture has been nominated based on an overall assessment of price and technical feasibility and performance. The contract, which has a value of 8.7 billion NOK, is scheduled to be signed before Easter and the work will commence immediately thereafter. The award value is within the project budget.

This is the second of four large 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 (NNRA) on behalf of the Ministry of Transport and Communications.

Attention from major contractors- The Norwegian National Rail Administration has chosen an EPC contract strategy for the majority of the work to be executed for the Follo Line Project. The magnitude of the project and this contract has attracted interest from major national and international contractors. The competition has been extensive and the project has been well received, explains Deputy Director General Gunnar G. Løvås.

The contract covers both conventional drilling and drilling by tunnel boring machines, in addition to railway system installations and comprises construction work to be performed without proximity to railway operations.

Two separate tunnels

In addition to the development of a large rig area at Åsland, this contract includes the blasting of large assembly halls located approximately 1 km inside the mountain. Access tunnels to this area are currently under construction under a separate preparatory contract. In the assembly halls, the four tunnel boring machines will be assembled from prefabricated parts prior to operation. The tunnel boring machines will have a diameter of less than ten meters. Two separate tunnels of 19 kilometers each, will be excavated by TBM between Oslo and the new Ski station. Two machines will drill north towards Oslo and two machines will drill southward toward Ski. The northern part of the tunnel will be operated partly by conventional methods and partly by drill & split. This work is part of another contract.

The Joint Venture will also perform all the railway installations, with the exception of the signal system. All mechanical and electrical equipment in the tunnel will be installed in approximately half of the 44 cross connections to be built between the two tunnels. The cross connections will be used for evacuation between the tunnels.

A significant contract
- For several reasons this is a significant contract. This is due to the magnitude, the fact that railway technical installations are included for the first time in an EPC contract of this size and that this is the first tunnel contract in Norway to include the use of four tunnel boring machines, says Project Director Erik Smith in the Follo Line Project.

- We are pleased that this important EPC contract for the Follo Line Project has been met with such large interest. The offers we have received and the possibility for us to nominate the JV indicates that the strategy and the terms of contract for this tunnel work are correct, emphasizes Erik Smith.

Acciona and Ghella have experience from previous cooperation in the performance of several similar mega projects regarding tunnel and rail construction. In 2009 they completed the Italian Bolognia Junction High Speed Railway Line and in 2015 they will complete the Legacy Motorway Tunnels in Brisbane Australia.
Both companies can demonstrate industrial history through several generations and have their headquarters respectively in Madrid and Rome.

The Joint Venture has sourced key competence in Norway through the Norwegian departments of PEAB and Atkins. The cooperation concerns respectively groundwork at Åsland and railway engineering expertise. Through the law firm Haavind, the JV will ensure that Norwegian employment rules and wage conditions are fully understood and complied with.
In accordance with Norwegian and European public procurement legislation, a complaints period is allowed which, to reflect the size of the contract, has been set at 16 days.

The rig area 
At Åsland, in the outskirts of Oslo, the AF Group is preparing a rig area for the handling of the TBM construction work. Concrete elements to be used in the tunnel will be produced at Åsland. Currently two access tunnels are being prepared to provide access to where the two main TBM tunnels will be excavated. In the construction period the access tunnels will be used for incoming and outgoing traffic, in addition to the transporting of excavated materials which will be accomplished on conveyor belts. The access tunnels are also important for the air supply to the main tunnel.

The rig area at Åsland also includes a transformer station for providing power for the excavation with tunnel boring machines.

Via Wikimedia Commons
Image,video ©: I, Besse