Helge Eidsnes, Regional Director of the Norwegian Public Roads Administration (NPRA), has now signed a contract with two advisory teams. The two teams will study and advise which concept is the best choice for the crossing of the Bjørnafjord, south of Bergen.
The NPRA has studied the Bjørnafjord since 2009. The fjord is five kilometers wide and close to 600 meters deep. Crossing the fjord will depend on the development of new bridge technology.
The two teams
Team 1: Aas-Jakobsen, COWI and Multiconsult with Johs Holt
work will start all in November 2018.
Team 2: Norconsult, Dr.Techn. Olav Olsen and Prodtex.
The two advisory teams will work in parallel with developing new technology and studying 4 different floating bridge concepts:
- Option 1: Floating bridge. The bridge is only held at each end.
- Option 2. Floating bridge including anchoring system. The anchor ring system is activated only by a possible extreme event, and in such a situation it can prevent progressive fracture development for the structure.
- Option 3. Floating bridge as a beam bridge. The bridge is held at each end and also has anchoring lines for anchors on the seabed. The anchoring lines ensure the necessary stiffness of the bridge in the horizontal plane. The bridge is aligned in the horizontal plane.
- Option 4. Floating bridge, which equals option 3, but in this option only the bridal chain of the bridge is straight-line. The floating bridge is curved.
Based on the work of the advisory groups, the NPRA will make a decision on floating bridge concept for the Bjørnafjord in 2019.
The companies have joined forces with specialist competence in transport and bridges, as well as offshore and marine engineering. Both groups are awarded contracts until August 2019, with the option of expanding the contract.
– The NPRA wishes a thorough investigation to ensure that we make the correct choice of concept for the crossing of the Bjørnafjord, says Øyvind Kongsvik Nedrebø.
A challenging project
Svein Erik Jakobsen from Aas-Jakobsen is the project manager for team one.
– This is perhaps the most challenging project in Norway in modern times, and we are looking forward to help with bringing this closer to realization, says Jakobsen.
Kolbjørn Høyland is a contractor in Dr.Techn. Olav Olsen.
– We have many ideas on how to reduce costs. We will work together with the NPRA on how to achieve reduced cost, but not on the expense of a robust and safe construction, says Høyland.
Predictable travel times
The floating bridge will replace ferry crossing, which normally takes 40 minutes today. In the future, it will take 11 minutes to drive over the fjord.
A more predictable travel route with significantly reduced travel time will give great effects according to preliminary calculations performed by the NPRA. A more predictable travel route and a significantly reduced travel time gives great social gain according to calculations made by the Norwegian Public Roads Administration.
The floating bridge will be five kilometres long, comprising four traffic lanes, and a 100 km/hr speed limit. It will also have a separate lane for pedestrians/cyclists.