The Alpine Mega-Tunnel

Der Spiegel is running an interesting story titled The Alpine Mega-Tunnel

The new Gotthard railway tunnel in the Swiss Alps will be the longest in the world. The unmanned elevator races down the shaft and comes groaning to a halt right in the warm, damp belly of the Tgom mountain. Perfectly on schedule, it will shortly take half a dozen construction workers almost one kilometer (0.6 miles) up to the mountain's surface.

Almost 1,000 meters of mica slate and gneiss lie above the enormous rocky cavern. Warm water seeps through its walls. An elaborate ventilation system lowers the air temperature in the huge space from more than 40 degrees Celsius (104 degrees Fahrenheit) to about 28 degrees (82.4 degrees Fahrenheit).

Since 1993, excavation work has been going on at this construction site and three others. A total of 13 million cubic meters (459 million cubic feet) of rock -- the equivalent of five Cheops pyramids -- will have to be removed from the mountain massif so that high-speed trains travelling at 250 kilometers an hour (155 mph) will be able to race through the Alps ten years from now.