Ambitious Infrastructure Project Unveiled
For several years, the Spanish government has been immersed in a colossal project aimed at connecting the Iberian Peninsula with Morocco through an underwater tunnel. In mid-March 2026, the government approved an additional transfer of 1.73 million euros to finance the technical studies required for this infrastructure. Currently, the project, which is being developed by the Spanish Society of Studies for Fixed Communication through the Strait of Gibraltar (SECEGSA), is envisioned to consist of a tunnel approximately 65 kilometers long, with around 40 kilometers traversing Spanish territory. The northern entrance is planned to be located near Vejer de la Frontera.
The proposed infrastructure will feature two independent railway tubes, each with a single track, along with a service gallery designated for emergencies and maintenance. At nearly 500 meters deep at its highest point, the journey between Spain and Morocco could be completed in about 30 minutes, thanks to this underwater tunnel. However, the estimated cost of the Spanish section alone exceeds 8.5 billion euros, and a report by the German tunneling specialist Herrenknecht indicates that this project poses extreme complexity.
Feasibility Studies and International Collaboration
The Spanish Society of Studies for Fixed Communication through the Strait of Gibraltar (SECEGSA), a public entity established in the 1980s to promote the construction of the tunnel, commissioned Herrenknecht Ibérica to conduct a feasibility study. After several months of analysis, the Spanish subsidiary of this multinational tunneling company has confirmed that, while the most challenging section of the strait will present significant difficulties, it is technically viable within current engineering limits.
The report particularly focused on assessing the feasibility of drilling through the "Camarinal Threshold," an underwater elevation separating the Mediterranean Sea from the Atlantic Ocean. The findings are optimistic, although they caution that executing this task will involve enormous logistical and economic challenges.
With this study in hand, Spain and Morocco have taken a crucial step forward in this ambitious project. Transport Minister Óscar Puente and his Moroccan counterpart, Karim Zidane, convened at La Moncloa to sign a Memorandum of Understanding that will facilitate joint research on seismicity and geodynamics in the Strait. This analysis is vital before commencing construction, which will start with a reconnaissance gallery that will serve as the first phase of the tunnel.
The agreement lays the groundwork for studying seismic activity, potential earthquakes and tsunamis, as well as the geodynamic behavior of the Strait over the next three years. If the studies yield favorable results, approval can be granted to excavate the reconnaissance gallery, with initial bidding potentially occurring in 2027. This preliminary phase is estimated to require between six to nine years for completion.
If materialized, the underwater tunnel between Spain and Morocco would span a distance of 42 kilometers between terminal stations, with a total length of 38.5 kilometers, of which 27.7 kilometers would be underwater. The minimum clearance at the lowest point would be 175 meters, reaching a maximum depth of 475 meters, with a gradient of 3%.
"The excavated tunnel solution anticipates the connection of the Moroccan terminal located in Tangier with the Spanish terminal situated near Punta Paloma. The main works are depicted in the schematics below and will consist of two single-track railway tunnels with a circular cross-section of 7.90 meters in inner diameter, a service/safety gallery of 6 meters in diameter centered between the two, and cross galleries every 340 meters, each with a diameter of 6 meters. From a safety perspective, a Safe Parking Zone (ZAS) is planned at the lowest point of the tunnel, which will include stopping areas in the railway tunnels, safety zones, and intervention zones, along with a smoke extraction gallery," details SECEGSA.
The marine campaign is set to take place before the end of the first half of 2026 and is expected to last approximately 15 days of work at sea. Planned tasks include high-resolution bathymetric studies using multi-beam sonar, subsoil analysis with a parametric probe (sub-bottom profiler), sediment and rock sampling from the seabed, and laboratory tests and scientific interpretation of the data.
The CSIC will conduct the campaign through three of its specialized institutes: the Institute of Marine Sciences (ICM), the Geological and Mining Institute of Spain (IGME), and the Spanish Institute of Oceanography (IEO). The Hydrographic Institute of the Navy and the United States Geological Survey (USGS) will also collaborate within an international working group.
All information obtained will be integrated into a three-dimensional geological model of the Camarinal Threshold, deemed essential for assessing the technical viability of the underwater tunnel between Spain and Morocco. This endeavor has received funding from the Spanish government, co-financed by the European Regional Development Fund for ultra-peripheral regions for the transport of goods in the Canary Islands. "A way to make Europe," concludes the report.
As reported by okdiario.com.
