If once we know, that we don't have anything to fear concerning the gases or even eruptions, we could start with the drill. We have to drill the centre cone, four entrances and the rooms.

© AlpTransit Gotthard AG 

Swiss ingeniers have a big knowledge about drilling, because of many miles of drilling for the transit through the alps.

You may visit http://www.alptransit.ch for further informations.

 
© AlpTransit Gotthard AG (both pictures)