Under one of Europe’s busiest mountain passes, a multi-billion euro project advances through the rock to remove trucks from the road and connect the north to the south of the continent in an almost straight line.

In the heart of the Alps, between Austria and Italy, giant tunnel boring machines and loads of dynamite are carving a path through the mountain. The goal is to create a train corridor that passes under the peaks instead of climbing over them.

When completed, the Brenner Base Tunnel will be 55 kilometers long and will take the title of the longest underground railway crossing in the world from the Swiss Gotthard.

A flat tunnel through a mountain range

The term base tunnel aptly describes the concept. Instead of following the ascent and descent of the mountain range, the route cuts through the bottom of the mountain, keeping the track almost flat from one end to the other.

ARTICLE CONTINUES BELOW

See also

When it seemed that oil would only rise, a turnaround between the US and Iran brought prices down and changed the global scenario in a few hours.

Neighboring country takes €1.3 billion out of its pocket and will build the largest urea factory in Latin America, a giant with 80 hectares, producing 2.1 million tons per year and more than 3,500 jobs.

The tax on blouses may return after a surge in international purchases, and the government is already considering revising the tax on orders up to US$ 50.

U.S. tariff hike pressures Brazilian exports, which fall 13% and total US$ 17.4 billion in the first half of 2026, while the U.S. share declines to 9.4%, the lowest level since 1997, with losses concentrated in coffee, oil, and steel, and new surcharges increasing pressure on the industry.

This changes everything for a freight train. Gentle slopes allow for longer and heavier trains, pulled by fewer locomotives, with lower energy consumption and reduced risk.

The Brenner connects the Innsbruck region in Austria to Fortezza in northern Italy, crossing the border entirely beneath the rock.

55 kilometers that become 64 and surpass the Gotthard

The main tunnel will be 55 kilometers long. Combined with an already existing underground railway link on the Innsbruck side, the continuous underground route reaches about 64 kilometers.

This number secures the record. The current titleholder, the Gotthard Base Tunnel in Switzerland, is 57 kilometers long and has reigned as the longest since it was inaugurated.

The Brenner takes the lead and joins a select group of mega-projects that prefer to cross mountain ranges from within rather than bypassing them from above.

Two galleries and an exploration tunnel below

The project is not a single hole. There are two main parallel tubes, one for each direction of traffic, connected by transverse passages at regular intervals, used for safety and rescue.

Below them runs an exploration tunnel, excavated ahead of the main galleries. It serves to study the rock before the final excavation and later for drainage and maintenance.

This layered architecture is what allows the project to proceed with more predictability, reducing geological surprises over dozens of kilometers.

Tunnel boring machine and dynamite against the Alpine rock

The excavation combines two methods. In much of the route, giant tunnel boring machines advance by biting into the rock and lining the tunnel as they move.

In sections with more complicated geology, the team resorts to the drill and blast method, opening the rock in controlled cycles of explosives and debris removal.

On top of all this, the alpine massif reaches about 1,700 meters of rock between the tunnel ceiling and the mountain tops, one of the reasons why the project is so slow and expensive.

The real target is to take trucks off the road

The Brenner is not a vanity project. The pass that bears its name is one of the most used Alpine crossing routes for road freight transport, with lines of trucks and a strong environmental impact on the valleys.

The idea is to transfer a large part of this flow to the rail. A flat and fast corridor under the mountain makes the train competitive against the truck, promising less pollution and less congestion on the hillside roads.

For passengers, the effect shows on the clock: the train journey between southern Germany and northern Italy should shorten significantly when the line becomes operational.

A billion-dollar project that only finishes at the end of the decade

None of this is quick or cheap. The project involves an investment in the billions of euros, divided between Austria, Italy, and the European Union, and drags on for more than a decade of excavation.

The forecast is that the tunnel will be fully operational by the end of this decade, after the galleries are completed, the track is installed, and the long safety tests required before any train circulates are conducted.

Until then, the Brenner remains one of the largest engineering projects underway in the world, silently digging the record that will take the title of the longest railway tunnel on the planet from the Gotthard.