A vital traffic connection between northern and southern Europe lies in the Austrian Alps. While motorists have long dealt with traffic jams and pollution levels have continuously risen, a massive engineering feat has slowly been moving forward beneath it to create the longest underground railway link in the world: the Brenner Base Tunnel. Set to open in 2028, 11 excavation sites in Austria and Italy continue work on creating the Brenner Base Tunnel through the Austrian Alps, set to be the longest railway corridor in the European Union.
Part of the Mediterranean Corridor, which links Norway, Sweden, Denmark, Germany and Italy, the new tunnel eliminates traveling along the steps grades that require slower travel. Instead of 60 to 110km/h and a 30km/h speed restriction through Brenner station, the tunnel will allow freight trains to travel 120km/h and passenger trains to travel at 250km/h. For now, the massive undertaking, which started in 2008, is only 50 percent through the excavation process.
This intense project is estimated to cost €9.2 billion with the European Union contributing 40 percent of construction costs and Austria and Italy investing 30 percent each. Brenner Base Tunnel between Innsbruck, Austria, and Fortezza, Italy, will have a length of 55km, making it the second longest after Gotthard Base Tunnel in Switzerland, which is 57km. Since the BBT will connect with an existing bypass tunnel, its length will increase to 64km.
The construction phase, which surpassed 115km of the total 230km in December, has required significant communication between companies and countries. There are four construction lots in Austria and Italy—Tulfes-Pfons, Pfons-Brenner, Mules and the Isarco River Underpass—that includes 11 ongoing excavation points. Approximately 1,900 workers are clearing approximately 500m per week using mechanical and explosive methods.
A unique aspect of the tunnel is a third tunnel tube, which is an exploratory tunnel meant for geological purposes. It allows for easier access to rock mass information and enhanced logistics, which has helped to minimize costs. It will serve as a drainage and maintenance tunnel after project completion.
Once finished, the tunnel will have two single tracks that are 8.1m in diameter and 40 to 70m apart. It will be electrified using 25kV, reducing CO2 emissions, and has been designed with ecological factors in mind, one of the many considerations in determining the true benefits of using railway as a major mode of transportation.
Challenges thus far faced during construction have included crossing the Periadriatic fault line and tunneling below the Isarco River, as well as related projects on connecting lines and developing an integrated transport policy for cross-border travel.
According to Ekkehard Allinger-Csollich, chief officer of traffic planning with the Tyrolian state government, the shell of the twin-bore tunnel is scheduled for completion in 2025. If all goes as planned, the tunnels will be open for business in 2028.