FCC has finished excavating the left-hand tunnel of the northern access to the Atlantic High-Speed Corridor -Vigo-Das Maceiras section-, which will connect Vigo and A Coruña. This is one of the longest, most important tunnels in Galicia.

The tunnel is 8.5 kilometres long, including 300 metres of cut-and-cover tunnels. There are two separate circular tubes connected to one another by cross-passageways every 500 metres. Altogether 16.4 kilometres of tunnel will be excavated, using two double-shielded tunnel-boring machines working at a boring diameter of 9.5 metres.

The left-hand tube has been bored by the TBM A Miñoca, in a process that has taken two years and eight months to complete. The tube's path lay through an area rich in highly abrasive, hard-to-penetrate granite in the Schistose Domain of the Tras os Montes zone.

The tunnel follows a straight line pointing southwest/northeast, and it begins with a downward slope. The first 387 metres of the Das Maceiras mouth were built using a combined system of excavation: The conventional dig-and-shore method was used first, and then a TBM was deployed to bore out the lower section.