The tunnel connecting Scandinavia to the Mediterranean represents a significant north-south axis for the European economy. The corridor stretches from Finland and Sweden in the North to the island of Malta in the South, taking in Denmark, Northern, Central, and Southern Germany, the industrial heartlands of Northern Italy, and the ports of Southern Italy, thanks to a bridge over the sea at Copenhagen, it’s all pretty easy-going, until you reach the mountain range called the Alps. That has slowed traffic for decades, turning an ordinarily smooth highway into a painful bottleneck. To solve the problem, the EU is digging an $11BN tunnel directly through the very heart of the mountains to connect Scandinavia to the Mediterranean effectively.

The Alps present a significant barrier for people and freight to cross between Northern and Southern Europe.

Project Details | Tunnel Connecting 

The Wilten neighbourhood of Innsbruck serves as the starting point of the 55 kilometres (34 miles) long twin-tube tunnel Connecting Scandinavia to the Mediterranean that travels through the Alps to a height of around 840 meters (2,760 feet) above sea level (ASL). The gneiss part of the tunnel, which extends south from the Italian border, will be the deepest, reaching a maximum depth of 1,720 m (5,640 ft) below the surface. The diameter of the major tunnels’ circular cross-section, which will be about 8.1 meters, is (27 ft). 

On its north end, the tunnel Connecting Scandinavia to the Mediterranean, the base tunnel (BBT) has two entrances, which must go underground a few kilometres before the junction with the main tunnels and will be built as part of the BBT. The 165 km (103 mi) Grafing-Rosenheim-Kufstein route is the northern approach from Munich within Germany. From the tunnel’s southern entrance in Franzensfeste/Fortezza to Verona, the southern approach for the BBT will be 189 kilometres (117 mi) long. Planning has been finished for several sections.


The Brenner railway, built in 1867 to increase capacity, was joined by the E45 motorway in the 1970s, forming a key freight route for traffic travelling from the North Sea to the Mediterranean and back. Since the start of the project in 2008, excavation has been moving forward at four major locations for more than ten years. Due to the topography, it would be very difficult to repair the current railway. Thus, the EU constructed a brand-new railway tunnel through the Alps. The primary section of the tunnel will be 55 kilometres long, running from Innsbruck in Austria to Fortezza in Italy. The project would surpass the Gotthard tunnel in Switzerland as the longest underground railway network in the world, with a total length of 64 km combined with sub-tunnels built near Innsbruck in 1994.

Construction Materials and Methods

It probably won’t surprise you that digging a long tunnel Connecting Scandinavia to the Mediterranean through a mountain is not easy – and this is no exception. The tunnels were built using conventional blasting and tunnel boring (or TBM) techniques since the route passes through four rock types and one of Europe’s longest fault lines. Explosives are put into pre-drilled holes and set off for sections made by blasting. 

Project in-depth: Tunnel Connecting Scandinavia to the Mediterranean - Sheet1
The BBT will consist of three separate tunnels connected every 333 meters. _©BBT SE

The loosening of the material is followed by “mucking,” which involves using large machines. Shotcrete is used to anchor the surface and stabilise it after it has been cleaned, and lattice arches and reinforcing matting are put in place to offer structural support. The entire process then continues and repeats itself. In theory, the TBM portions are considerably easier. As it advances through the rock, the machine excavates material, transports it away on conveyor belts, and inserts tunnel reinforcement on its own. Regardless of the technique employed, once the tunnels connecting Scandinavia to the Mediterranean are dug, they are finished mostly uniformly, with only small variations in the overall appearance. A staggering 21.5 million cubic meters of material will be dug for the 8.1-meter inner diameter tunnel connecting Scandinavia to the Mediterranean project. Almost a third of that material will be recycled and used as concrete aggregate inside the tunnel. 

Project in-depth: Tunnel Connecting Scandinavia to the Mediterranean - Sheet2
Tunnel reinforcement_©BBT SE

The remaining will be sent to five locations along the route for environmentally friendly disposal, filling areas that can be replanted with trees and landscaped after the project is finished, restoring the property to its original usage.

Construction process_©BBT SE

Latest Breakthrough

With the most recent development in the Tunnel Connecting Scandinavia to the Mediterranean, a continuous tube has been built from the southern portal at Fortezza in Italy to the Brenner Pass on the Austrian border. On May 19, an excavator broke through the last wall separating the Brenner Base Tunnel’s construction lots for H61 Mules 2-3 and H71 Isarco River Underpass. The two Italian building sites for the Brenner Base Tunnel are now directly connected by the most recent development. The result is a 24.1 km long tunnel uninterrupted between the southern portal and the state border at Brenner Pass.

What Does the Future Entail? | Tunnel Connecting

The highly straight Brenner Base Tunnel will enable trains to achieve 200 kilometres per hour when it is ultimately finished in 2032 – around 30 years after construction initially started – and the trip from Innsbruck to Fortezza would decrease from 80 minutes to only 25. It’s a feat of construction that will create a cleaner and more sustainable transport link not just through a mountain range between two countries but connecting from Scandinavia down to the Mediterranean. It is an engineering and building marvel. The Tunnel Connecting Scandinavia to the Mediterranean, the fifth of the Trans-European Transport Network’s nine priority axes, is a vital route for the European economy.  

  • Kajastie, N. (2022). Brenner Base breakthrough combines 24km of tunnel. [online] Ground Engineering (GE). Available at: [Accessed 9 Mar. 2023].
  • Wikipedia. (2023). Brenner Base Tunnel. [online] Available at: [Accessed 9 Mar. 2023].
  • (n.d.). The $11BN Tunnel Connecting Scandinavia to the Mediterranean. [online] Available at: [Accessed 9 Mar. 2023].

Preksha is an endeavoring architecture student who relishes traveling and reading. With a desire to create engaging and thought-provoking content, she is committed to rummaging through new ideas in architecture and design, sharing them with a broader audience, and inspiring positive change through her writing.