MOUNTAIN TUNNELLING.

Auckland Star, Volume XXXII, Issue 147, 22 June 1901, Page 2 (Supplement)

MOUNTAIN TUNNELLING.

It is well known that the temperature rises as we bore downwards into the earth, but it was hardly expected that so much heat would be met with when boring horizontally through a mountain. The Alpine tunnellings showed that the temperature rises very considerably as the heart of the mountain is neared. During the construction of the Mont Cenis tunnel a maximum of 85 deg. Fahr. was experienced, and in the St. Gothard 87 deg. It is estimated that for somethink like six miles of the Simplon tunnel the rock, when first laid bare, will show a temperature of 104 deg. While the St. Gothard tunnel was being cut no less than 600 lives were lost among the workmen, most of them indirectly in consequence of this heat. After engaging for hours in -vigorous physical toil inside the tunnel the men would go out into the Alpine coolness, take cold, and die., But if such results followed the construction of the St. Gothard tunnel, what might be expected of temperatures of 15 or 20 deg. higher for a much longer distance? These considerations have led to the adoption in the case of the Simplon of certain arrangements which it is believed will ensure a regular supply of cool, fresh air to the workmen.