94 TUNNELING 



CHAPTER X. 



TUNNELS THROUGH HARD ROCK (Continued). - 

 THE SIMPLON TUNNEL.* 



BEFORE entering upon a description of the constructive 

 details of this, the longest railway tunnel in the world, it may 

 be well to give a general idea of the undertaking. Many 

 schemes for the connection of Italy and Switzerland by a rail- 

 way near the Simplon Road Pass have been devised, including 

 one involving no great length of underground work, the line 

 mounting by steep gradients and sharp curves. The present 

 scheme, put forward in 1881 by the Jura-Simplon Ry. Co., con- 

 sists broadly of piercing the Alps between Brigue, the present 

 railway terminus in the Rhone Valley, and Iselle, in the 

 gorge of the Diveria, on the Italian side, from which village 

 the railway will descend to the existing southern terminus at 

 Domo d'Ossola, a distance of about 11 miles. 



In conjunction with this scheme a second tunnel is pro- 

 posed, to pierce the Bernese Alps under the Lotschen Pass 

 from Mittholz to a point near Turtman in the Rhone Valley ; 

 and thus, instead of the long detour by Lausanne and the Lake 

 of Geneva, there will be an almost direct line from Berne to 

 Milan via Thun, Brigue, and Domo d'Ossola. 



Starting from Brigue, the new line, running gently up 

 the valley for 1J miles, will, on account of the proximity of 

 the Rhone, which has already been slightly diverted, enter the 

 tunnels on a curve to the right, of 1,050 ft. radius. At a 

 distance of 153 yards from the entrance, the straight portion 



Abstract from a paper read before the Institution of Civil Engineers by Charles B. 

 Fox, Jan. 26, 1900. 



