Lötschberg Tunnel

The Lötschberg Tunnel is a 14'612 m long railway tunnel of BLS AG of KanderstegGoppenstein car train in Switzerland. He is a einröhriger double -track tunnel and heart of the Lötschberg line from Spiez to Brig

Planning

As the largest building in the Lötschberg line a tunnel should connect the Kander Valley and Valais. The project manager William Teuscher studied different variants in order to penetrate the 3,500 meter high Alps. The variants foresaw a 7 km long summit tunnel in Gasterntal and two longer tunnel from Kandersteg plateau, Loetschental. Finally, the " Version D " of KanderstegGoppenstein car train with a 13'725 m long tunnel and a straight tunnel axis was chosen under the Balmhornmassiv. The tunnel was originally planned single track with a shunting station for train crossings of 500 m length along the tunnel center.

On 14 July 1906, the first triangulation survey of the tunnel axis occurred. These were repeated and completed by Prof. Baeschlin on October 1, after the first surveyor who died unexpectedly. The construction of the tunnel was transferred to the construction consortium Entreprise Générale du Lötschberg (EGL ).

Construction

Construction

On 15 October 1906, the work began with the removal of mountain rubble before the future north portal of the tunnel. On November 1, began in Goppenstein the construction work on the tunnel itself, a day later on the north side near Kandersteg. It was first worked in the tunnel with modest means by hand. Mechanical rotary hammers met in Kandersteg in January 1907, and were used from 7 March. In the south, the delivery of hammer drills took longer to much and the mechanical drilling did not start until 9 April 1908. Blame for this delay have included delays in the construction of the two Baubahnen of Frutigen and Naters up at the tunnel portals. Rotary Hammers and the studs locomotives were powered by compressed air. The main gallery had a height of 2.2 m and a width of 3.5 meters: at the tunnel front seven days worked 17 to 20 miners in eight-hour shifts a week. Only during Easter and Christmas, the holes were set.

In August 1907 a federal subsidy for the double-track extension of the tunnel has been approved and increases the diameter of 8.8 meters. Early 1908 worked around 1,700 people at the tunnel, where the majority of Italian origin was. Around 220 engineers and foremen were mainly Swiss and French. Most had already worked with other major projects around the world, a large part came directly from the construction of the Simplon Tunnel.

Accidents

On February 29, 1908 went after days of snow on the south side of an avalanche down and spilled the accommodation of the workers. 25 people were killed.

Took place on July 23, 1908 at 2:30 clock, at 2,674 kilometers an explosion in the 100 meters above expected unconsolidated rocks of Gasterntals. Instant invaded about 7000 cubic meters of sand, gravel and mud masses 1.5 km wide in the tunnels and buried everything in its path. 26 workers were trapped and killed in this accident. Only the body of Vincenzo Aveni was found and buried on behalf of all his comrades in the cemetery of Kandersteg. In the valley floor of the valley Gastern a terrain reduction of 3 m deep was formed.

Even during the accident investigation decided the EGL, the project by again. At first it was planned to retain the original, straight driving shaft after this accident. Advancing into the buried tunnel was tried several times by repeatedly nachrutschenden debris but prevented. The tunnel consortium made ​​it his work to the approval of a bypass through the BLS management. On August 4, 1908 bricked and so also leave the bodies of 25 miners Italian final in the mountain of the EGL of the old tunnels.

The Federal Council approved in December 1908, construction of the bypass tunnel with the resulting curved lines of the tunnel. The tunneling work was resumed on 15 February 1909. The new cleat guide the Gasterntal was driving at kilometer 5.1 without problems and the tunnel was extended by 807 meters. This results in a new total length of the Lötschberg tunnel from 14'612 meters revealed.

On January 20, 1910 barring a yearly low continuous avalanche that Rücklaui, the south portal of the tunnel. In the snow a hole had to be dug in order to extract the 30 miners working in the mine can. People were not injured. The two portals were subsequently extended to protect against falling rocks and avalanches artificially by 15 meters ( north side) and 55 meters (south side).

Puncture

On March 31, 1911, the hammer drill broke through the last of the south side, about 80 cm thick wall of separation. With Handbohrhämmern the hole was enlarged and the two engineers shook hands. As compensation, the miners of the north side were the last blast ignite. By twelve sticks of dynamite broke at 3:55 clock at 7367.29 meters from the north portal and 7237.80 meters from the south portal of the dividing wall collapses.

The difference in the encounter was in spite of the bypass tunnel Gegenortvortrieb horizontally only 25.7 cm and height 10.2 cm. On 31 March 1912, the excavation works have been completed. The construction workers and machines were in the two tunnels of Mont -d'Or tunnel and the tunnel Grenchenberg further used.

In - Shutdown

The rails for the standard gauge were moved from 20 July 1912 to September 28, the first track could be driven. After completion of the second track and installation of the catenary drove on 3 June 1913, the first electric locomotive through the tunnel. Three days later, the Federal Authority took off the tunnel and granted the operating license. On 15 July 1913, the Lötschberg line was opened to public traffic.

Data

• Length: 14'612 meters
• Height north portal: 1'200 m asl
• Height south portal: 1'216 m asl
• Apex: 1'239, 54 m asl
• Slope north side: 5'390 m = 7 per thousand; 1'690 m = 3 per thousand
• Slope south side: 4'328 m = 3.8 per thousand; 2'819 m = 2.415 per thousand
• Inclination tunnel middle: 308 m = 0 per mil

Source and Literature

• Patrick Belloncle: The Story of the Lötschberg Railway. Éditions du Cabri, Breil -sur -Roya, 1986, ISBN 2-903310-49-1.