Officials break ground on world’s longest underwater rail tunnel connecting 2 major cities: ‘A milestone in … history’

Construction has begun on what will be the world’s largest underwater road and rail tunnel connecting Denmark and Germany, as Newsweek reported.

The tunnel, which is a major component of the European Union’s Scandinavian-Mediterranean corridor plan, runs beneath the Fehmarn strait for more than 11 miles and aims to cut travel times between the two countries. A 45-minute ferry ride may soon be reduced to a quick seven-minute train commute.

Denmark’s transport minister, Thomas Danielsen, called the project “a milestone in Danish history” at a ceremony celebrating the progress, per the report. He continued, “With the Fehmarnbelt tunnel, we get a fantastic and cross-border infrastructure project.”

Road and rail traffic on routes between the north and south are currently detoured approximately 300 miles due to the waterway. Soon, as Forbes noted, train travel between Hamburg and Copenhagen may take three hours instead of five. Plus, drivers between the two zones are expected to save an hour by using this more direct route.

Any large construction project these days receives heavy scrutiny over potential environmental impacts, and the Fehmarnbelt project is no different. Others have also questioned the impact of the tunnel on reefs in the Baltic Sea. The developers have positioned this as an eco-friendly alternative to pollution-heavy air travel.

“While all such infrastructure projects have substantial carbon emissions from construction, some have the potential to pay it back over time, through lower emissions from reduced or changed traffic patterns,” Søren Have of Copenhagen-based climate-focused think tank Concito told Newsweek. “The Fehmarnbelt tunnel is such a project.”

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The contractors, Sund & Baelt, see it as advancing the green transition for the transport sector and are working to be climate neutral in both administration and operations by 2030, which is approximately when the project aims to be completed.

Walking or biking aside, rail transportation is one of the least polluting ways to travel. Taking a train for medium-length journeys instead of a car could reduce planet-warming pollution by around 80%, according to Our World in Data. Riding them instead of taking short-haul flights can reduce that pollution output by 86%.

Clearing the way for more extensive train lines can cut travel times for commuters — and reduce pollution from low-occupancy vehicles on the road (though electric adoption would eliminate that problem).

According to Newsweek, the tunnel is scheduled to be ready for commuters by 2029.

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