Seelisbergtunnel
The Seelisbergtunnel is part of the A2 motorway between the cantons of Uri and Nidwalden and is therefore an important part of the north -south axis of Switzerland. The north portal is located high above Lake Lucerne in Beckenried northwest, the south portal in space Seedorf UR on the western shore of Lake Uri. The name does not get this tunnel as by a mountain of the same, but by the well-known place Seelisberg, which was the end of the left-side bypass of Lake Lucerne before the construction of the tunnel. The mountain massif, which is mainly traversed by Seelisbergtunnel, is 1,923 m above sea level. M. high Niederbauen Chulm. The 9292 meter long Seelisbergtunnel world was and is still in Switzerland, the longest double -tube road tunnel. It was built in 1971-1980.
Building
The tunnel has two tubes, which have a center distance of 25 meters at the portals. In the middle portion of the distance up to 60 meters to grow. In the two-lane tunnel tubes, the clear running room height is 4.5 meters and the road width 7.5 meters, plus 0.8 meters wide sidewalks on both sides. All 300 yards are cross connections exist between the tubes as escape routes.
The tunnels are ventilated four underground centers, two of which are at the portals Rütenen and Buel. In addition, there is the middle station Hattig that sucks the air intake with a 275 meter deep shaft and the exhaust air blows out and the means Central Huttegg that has a 640 meter long tunnel and a 189 meter deep shaft for air exchange.
Production
The production of the two tunnels was carried out in three contract sections. The Los Rütenen ( northern section ), consisted of 2 × 4300 meter tunnel and the ventilation control Rütenen and Hattig. It had its point of attack for the tunneling at the northern portal. The Los Buel ( southern section ) with the contact point on the south portal included 2 × 2900 meter tunnel and the ventilation center Buel. Both lots had a breakout cross section profile with a horseshoe 88-125 m² of space and were built in the display of mining drill and blast. The Los Huttegg (average lot) consisted of 2 × 2000 meter tunnel and the ventilation center Huttegg. The point was the later Lüftungsstolllen. The propulsion of the circular profile 111-115 m² surface was carried out with an American shield tunnel with a zipper tooth excavator and a Tübbingversetzmaschine. Maximum 230 miners were working in the tunnel.
Traffic
The tunnel is used by about 20,000 vehicles per day. He is admitted for an indicated top speed 100 km / h. The road, in contrast to most other road tunnel in Switzerland concrete slabs. Despite its length and monotony, it hardly ever came to significant accidents. Half of the few fatal accidents incurred in oncoming traffic due to blockage of the other tube.