Some Tunnelling Feats 63 



A year after opening of the Mont 

 Cenis tunnel a new one under Mont St. 

 Gotthard was started to link up Belgium, 

 Germany and Switzerland with Italy. This 

 has a length of slightly more than nine 

 miles, but the greatest achievement of the 

 engineers was undoubtedly the building of 

 several spiral approaches with which to 

 gain altitude. Thus the train doubles on 

 its course, so that there are places where 

 the locomotive and its train is running many 

 feet above where it was climbing a few 

 minutes earlier. The great advantage of 

 the air drill was demonstrated more clearly 

 in the St. Gotthard tunnel, the work being 

 accomplished in nine years. 



Next came the Arlberg tunnel which 

 was begun in 1880, and so great was the 

 progress made that it was completed in a 

 little over three years. The rate of progress 

 was close upon 30 feet a day, and by careful 

 organisation the work of bricking the tunnel 

 was carried forward at the same rate as it 

 was excavated. It will be clear that the 

 farther the boring is driven into the moun- 



