NORWAY: The second major tunnelling contract for Oslo’s Fornebu metro linehas been signed, following an agreement by local authorities in the Oslo metropolitan region and the county of Viken of a revised funding package to cover increased costs.
Running from a junction with the capital’s existing metro network at Majorstuen to the Fornebu peninsula in the southwest, the line is intended to support property development around the capital’s former airport. Serving six stations, it would run for 5·2 km in Oslo and 3·1 km in Bærum, with the depot and control centre located near Fornebu Senter. Construction began in 2020 with opening envisaged for mid-2027.
Veidekke Anlegg was selected in April as preferred bidder for the second of the four main tunnelling contracts, following a tendering process that began in mid-2021. Project promoter Fornebubanen pre-qualified six contractors, and received four final offers.
Valued at NKr1·15bn, the contract covers a 2·35 km section of the route from Lysaker in Bærum to Vækerø in Oslo, passing under the Lysaker River in an area of challenging geology. It includes the station caverns for Lysaker and Vækerø stations, as well as emergency access shafts. The tunnel will run close to Bane NOR’s busy cross-city main line, which must remain operational throughout the construction phase. Tunnelling is expected to be completed by the first half of 2025.
‘We are naturally pleased to have all the necessary decisions in place, so that today we could sign the tunnel contract with Veidekke’, said Fornebubanen Project Manager Andreas Finstad on June 24. ‘They have delivered a solid and thorough offer and have an experienced and competent team. Together, we will create a safe and good implementation, so that the tunnel section can be handed over within the framework of the project.’
Project budget revised
When initially approved, the Fornebubanan was costed at NKr16·2bn in 2018 prices. Of this, half would be funded by the central government, and half by the local authorities. However, following recent increases in construction costs, the two authorities have agreed a revised budget envelope of NKr27·6bn to NKr31·3bn.
The revised budget has been adopted following a quality assurance review by Dovre Group Consulting which was commissioned at the beginning of 2022. This proposed a number of cost saving initiatives, including the pausing of the planned redevelopment of Majorstuen station, and the adopting of an ‘optimised’ route that would shorten the line from 8·3 km to 7·7 km. The construction timescale has also been extended, in part to allow more time for complex construction work at Skøyen station. Opening is now envisaged for June 2029, plus or minus a year.
The review put the P50 expected cost at NKr20·5bn in 2018 prices, or NKr23·3bn at 2021 prices. The P85 cost including an uncertainty margin has risen from NKr18·5bn to NK23·2bn in 2018 prices or NKr26·4bn at 2021 prices. The revised budget comes with a proviso that it may still be exceeded as costs continue to rise and much of the construction has yet to be completed.
To provide additional funding, the authorities have reportedly agreed to increase the Oslo road congestion charge by an average of 40%. Property owners and developers along the route will also be expected to pay more through a value capture mechanism.