Engineering Wonders of the World
Volume III

THE GREAT TUNNELS THROUGH THE ALPS. the calculated length. It need hardly be said that such results betokened extreme accuracy in the surveying operations preliminary to laying out the tunnel’s centre lines. The Mont Cenis Tunnel is 7’9806 miles long, including the two curved entry tunnels, which meet the main tunnel, 7| miles long, some distance in from the portals Details. used for sighting purposes. At the French end the maximum dimensions are: width, 26 feet 2| inches ; height, 24 feet 71 inches. At the Italian end the width is the same, but the height is about a foot greater. The gradients from the French and Italian portals to the centre point are 1 in 45| and 1 in 2,000 respectively. It may be added that the Modane entrance is 3,945 feet, the Bardonnéche 4,379 feet, above sea-level ; that the greatest depth of rock immediately over the tunnel is nearly a mile ; and that the highest temperature recorded during the work was 87° Fahrenheit. The total cost was about £3,000,000, or £225 per yard ; the average progress made per day 2-57 yards. The opening of the Mont Cenis Tunnel revo- lutionized travel from France and England to Italy, and transferred a great portion of the Eastern mail and merchandise traffic from Marseilles to Brindisi and Genoa. So great were the advantages gained, that the Swiss The St. Gothard Project. determined to effect railway access to Italy over or through the great barrier of the Lepontine Alps. After mature deliberation it was decided to take a railway from Altdorf, at the south- eastern end of the Lake of Lucerne, up the valley of the Reuss to Goesch- enen, to tunnel from that point under the St. Gothard to Airolo, and so gain the head of the valley of the Ticino, through which the rails would be led down to Biasca, on the way to Lugano, Como, and Milan. As the scheme was of importance to Italy and to Germany, these countries contributed 45,000,000 and 20,000,000 francs respectively towards defraying the cost. Switzerland came in equally with Germany ; and as soon as the agreement was signed, the public sub- scribed a further 115,000,000 francs within twenty-four hours. M. Louis Favre of Geneva, who undertook the contract, died of apoplexy in the St. Gothard Tunnel before it was com- pleted. The summit tunnel was to be 9| miles long. This by no means represented the sum of tunnelling to be done, as in the 56 miles between Erstfeld in Switzerland and Biasca there are over 8 miles of additional subsidiary tunnels, including the three corkscrew tunnels on the north and the four on the south, of ONE OF THE STEAM LOCOMOTIVES USED ON THE ST. GOTHARD RAILWAY.