The incredible £598m tunnel stretching 4270m boosting transport between 2 pretty countries

The Rastatt Tunnel is a major transport project in Germany. (Image: Getty)

Civil works on a massive railway project in Europe have been completed, officials have announced. The 4,270-metre-long twin-bore Rastatt Tunnel is a major part of a scheme to ensure the section of a key Rhine Valley main line between Karlsruhe and Basel in Switzerland is extended to four tracks. Tunnelling, done using two tunnel boring machines (TBMs), has now finished, and final railway systems work is now underway.

The final part of the slab track, replacing the traditional elastic combination of sleepers and ballast, overhead electrification equipment, signalling, lighting and communications systems need to be installed. DB said it is working to ensure that the first trains are able to travel through the tunnel as planned by the end of 2026. The project is a key part of the around 200-kilometre upgraded line between Karlsruhe and Basel - one of the oldest rail lines in Germany. 

The railway line runs through key locations such as Mainz. (Image: Getty)

Bosses say this is crucial for domestic and international rail traffic, as the section is part of the "most important European rail corridor" between Rotterdam and Genoa.

DB said: "The new double-track line begins in the first section of the line between Karlsruhe and Rastatt South.

"The core of this section is the Rastatt tunnel, which is just under five kilometers long."

On its way from Karlsruhe, the new line runs parallel to the B36 highway east of Ötigheim.

Then it descends into a watertight concrete trough and passes through a tunnel under the city of Rastatt.

Officials say the tunnel is set to have trains travel through it in 2026. (Image: Getty)

Officials describe the Rastatt Tunnel as "one of the largest structures in the major Karlsruhe-Basel project".

The tracks the emerge from the tunnel at Rastatt-Niederbühl, in a concrete trough to start with.

They then cross under federal highway (BAB) A5.

It comes after work on the tunnel had to stop in 2017, when part of the eastern bore collapsed, the International Railway Journal reported.

This also caused major disruption to the railway, as the incident severed the existing main line on the surface.

The line reopened later that year after a 275-metre-long concrete slab was laid to support.