Europe is in a transition period as it attempts to leave behind the days of long train journeys across the continent, and replace them with quick and easy commutes courtesy of high-speed rail. This has led to some of the biggest tunnelling projects on the planet happening on the continent.

The biggest project currently under construction in Europe is the 57km Gotthard Base Tunnel, in the Swiss Alps. The USD 9bn rail tunnel project, once complete, will be the longest road or railway tunnel in the world, running between the Swiss cantons of Uri and Ticino. Four Herrenknecht gripper TBMs are employed on the job, which has an estimated completion date of 2017. In total, 153.5km of tunnels, shafts and passages will be constructed.

Another large project currently being undertaken in Europe is the Brenner Base Tunnel running through the Alps between Italy and Austria.With an expected completion date of 2025, the USD 6bn project will be the world’s second longest road or rail tunnel after the Gotthard. The final design will consist of two 55kmtunnels, with a centre tunnel used during construction as a guide tunnel to determine geological conditions, and later for drainage and emergency access.

The Italian and Austrian governments have each committed to pay 30 per cent of the construction costs, with negotiations underway concerning the rest of the funding. Once completed, 400 trains will pass through the tunnel every day, 320 of which will be freight.

The Brenner Base Tunnel will begin in Wilten, a suburb of Innsbruck in Austria, penetrating the Alps at a height of about 840m above sea level. It will tunnel at up to 1800m below the peak, before emerging in the Italian town of Fortezza.

Meanwhile, Germany’s longest underground construction, the Katzenberg Rail Tunnel project, is currently being excavated. The 9.4km twin tube tunnel will form part of the Karlsruhe-Basel railway line.

The USD 681M project is expected for completion at the start of 2012.

The Leipzig City Tunnel, considered to be one of Germany’s biggest inner-city infrastructure projects, is designed to end the inefficiency of reversals at a central terminus, improve connections and provide interchanges with surface running buses and trams. The USD 850M project is being carried out by Zweckverband for the Transport Area (ZNVL) and is scheduled for completion in 2012.

In Sochi, Russia, the Adler to Alpika Service Mountain Resort Rail Tunnel is being constructed at a cost of USD 800M. The 2.4km tunnel project was announced in 2007 and is scheduled for completion in 2013. The purpose of the tunnel, which is being built by the Directorate for Comprehensive Railway Renovation and Construction of Railway Transport Facilities (DCRC), is to reduce traffic congestion, travel time and distance across Sochi, close to the border with the Republic of Georgia.

Warsaw’s USD 944M Metro Development Rail Tunnel project in Poland involves the construction of a 47.2km tunnel. It is being constructed using both TBM and top-down drill and blast method. The second line will link the east and west of the city. The line will run at relatively shallow depths, with an average of 9m between track and ground level. The metro facilities will be constructed in Quarternary soil formations, mainly by the cut-and-cover method.

In Scandinavia, tunnelling is in no less of a boom time, however the emphasis is more on the roads rather than the rails. In Norway, Skanska is constructing the USD 60M, two-lane, 6.5km long Kvivs Tunnel, on the E39 motorway. The tunnel is being excavated between More og Romsdal and Sognog Fjordane in the west of the country. Completion is scheduled for mid 2012.

Also in Norway is the 1.2km Loren Tunnel project, scheduled for completion in 2013, that will form part of the Ulven- Sinsen road project. The contract, worth about USD 94M, was awarded to Veidekke Entreprenor in 2008.

For the time being the future looks bright for tunnellers after a difficult period.

The Brenner Base Tunnel, one of the largest tunnelling projects underway in Europe