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Historic Tunnel Breakthrough at Loetschberg

07/05/2005
Historic Tunnel Breakthrough at LoetschbergWorkers have blasted their way through the final metres of rock on 28th April, 2005 to pierce the 34.6 km Loetschberg rail tunnel, a key component of Switzerland's rail transit system. About 1,200 guests, including Moritz Leuenberger, the Swiss transport minister, attended an official ceremony marking the end of tunnelling. The junction was made between Ferden and Mitholz by the JV headed by Bouygues, including Losinger, Prader, Deneriaz, Evequoz, Imboden and Theler, who drove the tunnel northwards from Ferden. Work on the tunnel itself, which connects the Valais and Bern cantons, began in 1999. The entire tunnel and adit system, excluding cross passages, represent 88,064 m. Construction teams have been working from opposite sides, on five different worksites in Raron, Steg/Niedergesteln, Goppenstein/Ferden, Mitholz and Frutigen (from south to north). The final excavation was at the midpoint of the tunnel, some 1,800 m underneath the Balmhorn mountain on the border between Bern and Valais cantons. Drilling for the Loetschberg began in 1994 at Mitholz, near its northern end about 55 km south of the Swiss capital of Bern where construction first started on a pilot tunnel in Kantertal. The alignment of the main tunnel had to be extremely precise. The two halves of the tunnel met almost perfectly: the centre of the bore coming from the north was only 13 centimetres off the centre of the bore coming from the south and their heights were mere fractions of centimetres off. Approximately 2,500 people have been working on the tunnel system, with up to 1,800 working underground in shifts 24 hours a day, seven days a week. Conditions have been difficult in the tunnel and the air has been cooled inside to 28°C. The tunnelling has not been without risks. Five workers have been killed so far on the Loetschberg project and unions have called for improved safety measures and better healthcare. Despite difficult carboniferous geology in Mitholz, the final breakthrough takes places only 2 ½ months behind schedule compared with the estimate of the early 1990s. For a project of this magnitude, this is indisputably a major achievement and an engineering marvel.Construction has generated around 16 million tons of rock and dirt, 40% of which has been reused. Most of the Loetschberg project will be a dual tunnel system, although one section between Mitholz and Frutigen in canton Bern has only one tube. Journey time from Zurich to Milan will fall to 2.5 hours while trips between Germany and Milan will be shortened by an hour. On completion, the Loetschberg tunnel will be the longest under the Alps and the third longest in the world, behind Japan's 53.8 km Seikan tunnel and the 50.5 km Channel tunnel between the UK and France. The tunnel, along with a similar project under the Gotthard in central Switzerland, are key to the Swiss government's goal of moving north-south freight traffic through the Alps from road to rail. The Loetschberg is due to open in 2007, while the 57 km Gotthard base tunnel, where 44% of the rock has been excavated, will not open before 2015 or 2016. Both projects are facing major budget overruns (subscribe to E-News Weekly 16/2005, 4/2005, 41/2004, 30/2004, 15/2004 & 12/2004). The Loetschberg will now cost an estimated CHF4.2 billion (USD3.5 billion), 31% more than originally planned. The new base tunnel is the successor to a much older one finished in 1913. This tunnel, built higher up in the mountain, will continue for the time being to transport cars through the Alps. Click ch/18. Click here to view a video. Visit www.blsalptransit.ch 18/05. Guests plug their ears shortly before the last breakthrough of the Loetschberg base tunnel, Thursday 28th April, 2005, near Frutigen, canton Bern. Miners wave flags to celebrate the last breakthrough of the Loetschberg base tunnel, Thursday 28th April, 2005, near Frutigen, canton Bern.



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