Simplon Tunnel

Simplon Tunnel

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The opening of the Simplon Tunnel


After eight years in the making, the Simplon Tunnel officially opened between Brig and Iselle on 19 May 1906. Based on pilot studies conducted by Louis Favre, the Compagnie du chemin de fer du Simplon developed the concept for a base tunnel, which was showcased at the 1878 World's Fair in Paris. The Simplon design especially attracted crucial support in France and Italy, as well as the Swiss cantons of Valais, Vaud and Geneva. The project was revisited between 1881 and 1882. Albert Heim, a professor at the Polytechnikum (as ETH Zurich was called at the time), was in charge of the geological survey.         

The Simplon Tunnel was to be a twin railway tunnel between Brig and Iselle realised by the company Brandt, Brandau & Co. Alfred Brandt (1846 to 1899) came from Hamburg, had studied mechanical engineering at the Polytechnikum and worked as an engineer on the Gotthard Railway from 1875 till 1877. He founded a company with Karl Brandau, who had been at university with him, to market his technological innovation, a hydraulic rotary drill. In 1893 the company assumed the management of the Simplon Tunnel site. 

19,823 kilometres in length, it was the longest railway tunnel in the world for many years. The first tunnel was constructed between 1898 and 1906. Although the engineers ran into major water, rock and pressure problems on the south face, they eventually broke through on 24 February 1905. The first train finally travelled from Brig to Iselle on 25 January 1906 before the tunnel was officially inaugurated on 19 May 1906. The second tunnel, Tunnel II, was drilled alongside the first between 1913 and 1922.


Albert Heim

Profil géologique du tunnel du Simplon. (Hs 401:131)


ETH-Bibliothek's Collections and Archives contain documents from various holdings on the construction of the Simplon Tunnel.

The personal papers of Charles Andreae (Hs 1002) or Albert Heim (Hs 401) with plans, maps, profiles and postcards are located in the ETH-Zurich University Archives.

The Image Archive contains slides by Leo Wehrli (slide 247), for instance.

And various printed reports are found in the collection Rare Books:

  • Percement du Simplon: mémoire, plans et devis / Paul Cérésole. – Lausanne, 1882. (21011 Rar)
  • Développements complémentaires d'un avant-projet de chemin de fer par le Simplon / par Charles Jaquemin. – Lausanne: Imprimerie Georges Bridel, 1862. (3257 Rar)
  • Compagnie des chemins de fer de la Suisse occidental et du Simplon, linge traversée du Simplon... / Jean Meyer. – Lausanne:..., 1886. (31962 Rar)
  • Chemins de fer du Jura-Simplon: traversée du Simplon. – Berne: Staempfli, 1891. (31304 Rar)
  • Tunnel du Simplon: projèt de 1893 / texte par Giuseppe Colombo, Francis Fox et C.J. Wagner. – s.l.,ca. 1894. (32061 Rar)

All the documents in the Collections and Archives can be consulted in the Collections and Archives reading room. More recent literature, including on the history of tunnel building, can be searched for and borrowed via ETH Library's Search Portal.

ETHorama (external link) offers geographical access to images, texts and maps all about the Simplon tunnel: