A Capita Symonds project in Norway has reached a major milestone with the immersion of the first tunnel element in the Bjørvika Immersed Tunnel project in Oslo harbour.
The 600m long structure - part of a much longer network of tunnels carrying traffic beneath the city on the E18 highway – is made up of of six tunnel elements and will eventually carry a dual three-lane highway under the harbour. It is the first ever immersed tunnel in Norway
A Capita Symonds team – led by Associate Director Jon Baber – has been working on the project since 1999 when we provided advice on the project’s feasibility.
We also provided outline design and detailed design of the tunnel structure - working with Norwegian consultants Aas Jakobsen - as well as preparing contract documents. Our team is currently providing advice and site support during the construction phase.
The tunnelling contract is linked to the redevelopment of the harbour area which includes a new opera house as well as commercial and residential districts. The remaining tunnel elements are due to be in place by mid October before work starts on the road construction and the installation of the various mechanical and electrical systems. The €300m highway tunnel is due to open to traffic in 2010 with the remainder of the harbour development planned to be complete around 2012.
The immersed tube tunnel technique is highly specialised and Capita Symonds is one of only a few consultants in the world with the expertise to deliver this type of project.
The work involves the construction of large box-shaped tunnel elements in dry docks, or purpose built basins, which are then sealed with bulkheads before being floated up and towed to site where they are sunk into a pre-dredged trench in the river or sea bed. The tunnel elements are then joined together with a complex arrangement of watertight gaskets and, once backfilled, the road or railway can then be constructed internally.
Capita Symonds’ client on the project is the Norwegian Public Roads Administration while the contractor for the immersed tunnel is a joint venture between Skanska, BAM and Volker Stevin.
Our portfolio of immersed tunnel projects extends to over 30 major international schemes. It includes the Conwy Tunnel in North Wales, the Medway tunnel in Kent, the Jack Lynch Tunnel in Cork, Ireland and the largest concrete immersed tunnel in the world - the Øresund Tunnel between Denmark and Sweden. Our other current projects include the Limerick Tunnel in Ireland and the Tyne Tunnel in Newcastle where the team is providing technical advice to the lending bank.