Shani Wallis, TunnelTalk
Anticipated opening of the 28th subsea link
- The 28th undersea road tunnel in Norway celebrated an official opening on Saturday 19 December. In construction since August 2006, the 5.7km long Atlantic Ocean Tunnel passes some 250m below sea level at its deepest point to link portals at Øksenvågen in Averøy and Hagelin in Kristiansund and replace the Bremsnes-Kristiansund ferry connection. The subsea fixed link incorporates maximum 10% gradients (ascending 10m in every 100m) and third lane on the inclines allows for two lanes of traffic on the inclines in the otherwise two-lane, bi-directional roadway. The new, much anticipated, subsea crossing provides a 24-hour connection between Averøy and Kristiansund that will shorten travel times substantially and contribute significantly to regional growth and prosperity in a number of neighbouring municipalities, including Eide in Nordmøre and others in coastal Romsdal.
Officials perform the ribbon cutting honours
- After an excellent start, prime contractor Mesta A/S, had more than half the 5,735m drill+blast tunnel finished in little more than seven months. From the first tunnel blast in late April 2007, maximum average progress rates of about 100m/week, working from each portal, contributed to completion of 2,862m by November 2007. A series of incidents then caused severe delays from March 2008. A rock-fall in the Averøy section of the tunnel brought tunnelling to a stop before Easter 2008. At the same time week zones in both headings caused reduced progress and fires in a shotcrete spraying rig and two transport vehicles caused further interruptions. A later delay in Kristiansund, affecting disposal of tunnel muck was compensated for and breakthrough finally arrived in late 2008.
The Giertsen WG T100 waterproofing system
- The deep undersea rock tunnel is supported with rockbolts and shotcrete and is finished with the Giertsen Tunnel A/S waterproofing system. More than 100,000m2 with the company's WG T100 system is applied in the single-tube tunnel.
- While prime contractor Mesta A/S advanced the tunnel works, contractor K. A. Aurstad managed transport and stone crushing of the tunnel muck and Johs. J. Syltern built the 3.9km of connecting road on the Averøy side and the 600m of new road connection in Kristiansund, starting in August 2006 and in Autumn 2007 respectively.
- Of the NKR 635 million ($US110 million) cost, in 2005 values, some 70.5% (NKR 447 million) is to be financed by tolls. The remainder is provided 20% (NKR 127 million) by municipal subsidies/loans; 4% (NKR 26 million) by alternative use of ferry subsidies and 5.5% (NKR 35 million) by a highway capital grant in 2010.
- The toll corresponds to a 30% increase over the previous ferry fares and is collected in both directions. Five toll categories include a fee for private and public vehicles as well as the number of passengers in each vehicle. Automatic toll collection is therefore not possible. The toll, set just prior to the opening of the tunnel, is calculated to provide a payback period of borrowed capital within 18 years.
5.7km long route of Norway's 28th undersea road tunnel since the first was completed in Vardø in 1981
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