Follo Line first tunnel contract award 12 Feb 2015

Condotte of Italy is awarded the first of five large engineering, procurement and construction (EPC) contracts for the Follo railway line project near Oslo, Norway. The contract covers complex drill+blast excavation on the alignment approaches to Oslo.

Complex drill+blast works through Ekeberg Hill on Oslo Station approach

This mega project by Jernbaneverket (the Norwegian National Rail Administration) on behalf of the Ministry of Transport and Communications, is currently the largest infrastructure project in Norway and includes 20km of twin tube segmentally lined hard rock TBM excavation.

The offers from the prequalified tenderers have been thoroughly evaluated, and a decision made based on a technical and economic comparison. According to Norwegian public procurement legislation, the contract will be signed after the mandatory 10-day period for complaints has expired. The contract is valued at about NOK 1.2 billion (US$156 million) and is scheduled to be signed by the end of this month (February 2015). The main works will commence as soon as possible.

Challenging scope

Contract scope includes drill+blast excavation of the railway project alignment through Ekeberg Hill, close to Oslo Central Station. A three-track tunnel is to be built combining the inbound Østfold line, the inbound Follo Line, and the outbound Follo Line. The new double-track line will cross existing tunnels and infrastructure. Contract scope also includes construction of the new twin tube Follo Line tunnel between the exit of the three-track tunnel and 1.2km into the hillside; excavation of cross passages between the tunnels; underpassing of the Ekeberg Oil Depot and rerouting of a river into a tunnel conduit; and construction of the south portal as a concrete culvert that crosses under a road; the rebuilding of a ventilation tower and a railway bridge.

Four TBMs for Oslo-Ski Follo Line

Condotte (Societa’ Italiana per Condotte d’Acqua SpA), has been selected based on criteria combining financial and technical merits. The company has longstanding experience that is directly relevant to the task at hand. “This tenderer combines a competitive price, long experience and technical solutions which meet with our expectations,” said Erik Smith, Project Director for the Follo Line Project. “We are looking forward to a fruitful collaboration with Condotte.”

The scope of work to be performed includes the performance of all activities, including the provision of all resources, people, systems, equipment and materials and the execution of all engineering, procurement and construction as required by Jernbaneverket in the contract manual. The contractor will perform detailed planning and construction based on Jernbaneverket’s construction concept, with the owner ensuring that progress, quality, safety requirements, environmental requirements, noise regulations and working conditions are performed as demanded under the contract terms.

Four TBMs will operate two in each direction from a single central access adit

Preparatory works covered by ten construction contracts shared between Skanska, AF Group, Norsk Gjenvinning, Siemens, Implenia, Baneservice and KF Entreprenør, are due to end soon. Between them the main contractors have employed some 50 subcontractors to perform constructions at Oslo Central Station and close to Ski Station, as well as preparation of rig areas and access tunnels at the project’s main working access area for TBM tunnelling operations at Åsland (located about half-way between Oslo Central Station and Ski Station); at Sørenga (near Oslo Central Station); and in Klypen (close to Oslo Central Station).

Other companies are carrying out a monitoring program to ensure ground stability and environmental protection.

The Follo Line Project is a pilot for further construction of the Norwegian rail system.
It also includes a new double-track line between Oslo Central Station and the public transport hub at Ski; a twin bore 20km railway tunnel, the longest railway tunnel to date in the Nordic countries; extensive works at Oslo Central Station; construction of a new station at Ski and necessary realignment of the existing inbound Østfold line (on the approach to Oslo Central Station with a new tunnel, and between the new Ski station and the tunnel).

The magnitude of the project has attracted major national and international contractors’ interest. The new high-speed railway is scheduled for completion by the end of 2021 and forms the core part of InterCity development southwards from Oslo.