Execution of the Túnel del Espiño section (left track) on the Madrid–Galicia High-Speed Rail line, within the North-Northwest Corridor. The project, delivered by OHLA for ADIF (Spanish Railway Infrastructure Manager), runs through the municipalities of A Gudiña and Vilariño de Conso (Ourense) and represents a key milestone in enhancing high-speed rail connectivity between central Spain and the northwest of the country. The alignment was designed for double-track high-speed rail with international gauge, improving overall network capacity and efficiency.

The scope of the works included the full construction of the rail platform over more than 8 km, encompassing earthworks, drainage systems, structures, tunnel execution, relocation of affected services and easements, as well as the construction of transverse connections to ensure road permeability along the alignment. In addition, the project included the development of the platform at the western approach to the Porta de Galicia Station, a strategic component of the infrastructure.

A key feature of the project is the construction of the Espiño Tunnel for the left track, with a total length of 7,909 meters, including half of the connecting galleries. The tunnel, of twin-tube typology, has a total length of 16.3 km considering both tracks, of which approximately 8.2 km correspond to the left track. The excavation in mined tunnel extends over 7,839 meters under natural ground conditions, complemented by additional sections of cut-and-cover tunnel at both portals.

From a construction standpoint, the project involves highly significant technical magnitudes, including the excavation of 665,743 m³ in tunnel, the application of 57,050 m³ of shotcrete, and the execution of 147,928 m³ of concrete lining. These figures reflect the complexity of the works carried out in a demanding geotechnical environment, addressed through advanced construction solutions and a high level of technical expertise.