Megaprojects

Beneath the Strait: Europe and Africa’s Century-Old Dream Is Finally Becoming an Engineering Plan

Morocco, Africa as seen from Spain, Europe.

A view of Morocco, Africa, from the shores of Spain, Europe / Photo by Tom Lorber on Unsplash

For nearly fifty years, connecting Europe and Africa across the Strait of Gibraltar has been treated as something closer to science fiction than infrastructure policy. 

But in the past two years, the project has quietly shifted from a diplomatic talking point into an active engineering study – with feasibility reports, government funding, and a realistic (if distant) completion date attached to it for the first time in its long history.

Why a Bridge Was Never Going to Work

The idea of physically linking the two continents dates back decades, and early proposals often imagined a suspension bridge. 

That option was abandoned long ago, for reasons that become obvious once you look at the strait itself. 

The Strait of Gibraltar reaches depths of roughly 900 meters at its narrowest point, is subject to powerful, unpredictable currents where the Atlantic Ocean meets the Mediterranean Sea, and carries some of the densest maritime shipping traffic on the planet. 

A bridge tall and long enough to clear both the depth and the shipping lanes was never realistic – which is why every serious modern proposal has instead focused on a submerged rail tunnel, closely modeled on the Channel Tunnel between the United Kingdom and France.

The Route: Threading a Geological Needle

Rather than crossing at the strait’s narrowest and deepest point, engineers have focused on a route further west, across a shallower underwater ridge known as the Camarinal Sill. 

Even there, the numbers are formidable: current planning documents describe a twin-bore rail tunnel around 65 kilometers long, reaching a maximum depth of 475 meters below sea level – deep enough to rank among the deepest rail tunnels ever attempted anywhere in the world. 

The design calls for two separate single-track tunnels, one for each direction of travel, alongside a smaller central service and safety gallery – the same three-tunnel configuration used in the Channel Tunnel. If built as currently planned, the crossing itself would take only about 30 minutes.

The geology beneath the strait is part of what has kept this project on the drawing board for so long. 

The area sits within a genuinely difficult stretch of seabed, containing so-called flysch formations – layered, often unstable sedimentary deposits of shale, marl, and sandstone – combined with significant seismic activity, since the Iberian Peninsula sits near the boundary of the Eurasian and African tectonic plates, close to the same fault system responsible for the catastrophic Lisbon earthquake of 1755.

The Verdict: “Feasible, But Extremely Complex”

The most significant recent development came in December 2025, when Herrenknecht – the German company that is a world leader in the design of tunnel boring machines – delivered an independent feasibility study commissioned by SECEGSA, the Spanish state company overseeing the project. 

The study’s conclusion was cautiously optimistic: building the tunnel is technically achievable using current engineering methods, even though the flysch formations, seabed instability, and extreme depth will require preliminary exploratory tunnels, advanced seismic surveys, and specially adapted boring machines. 

It is a meaningfully different verdict than assessments made only a few decades ago, when the project was often treated as effectively impossible.

Timeline: Not for the 2030 World Cup

The project has picked up fresh political momentum from an unrelated event: the 2030 FIFA World Cup, which Spain, Portugal, and Morocco will host jointly. 

For a while, that shared tournament fueled speculation that the tunnel might open in time for it. Herrenknecht’s study put that idea to rest – the tunnel will not be ready for the World Cup.

The realistic schedule now looks like this: Spanish engineering firm Ineco is finalizing an updated preliminary design, known as APP07, due by August 2026 – the first full technical update to the project since 2007. 

If seismic and geological findings remain favorable, a tender for an initial exploratory tunnel could follow around 2027, a phase alone expected to take six to nine years to complete. Full construction and entry into service are now projected for sometime between 2035 and 2040.

What It Would Cost, and What It Would Connect

Current estimates put the cost of the project on the Spanish side alone at more than €8.5 billion, a figure widely expected to rise as detailed engineering and risk assessments continue. 

Financing is expected to depend on a mix of European Union co-funding, national government contributions, and Morocco’s own investment.

If completed, the tunnel would do more than shorten a ferry crossing. It would physically connect Spain’s high-speed rail network to Morocco’s Al Boraq line – the first high-speed railway on the African continent – creating, for the first time, a continuous rail corridor between two continents. 

In principle, that would make it possible to travel by train directly between cities like Madrid and Rabat, without ever boarding a plane or a ferry. Beyond passenger travel, planners and logistics analysts see the tunnel as a potential catalyst for trade, capable of shifting a meaningful share of current Spain-Morocco air travel onto rail and adding billions of euros a year in freight trade between the two economies.

A Pipe Dream, Slowly Becoming a Plan

None of this means the tunnel is imminent. A decade of geological surveys, exploratory boring, seismic risk assessments, and financing negotiations still separates the current studies from an actual, operating railway. 

But for a project that spent nearly half a century as a diplomatic aspiration more than an engineering one, the shift is notable: for the first time, there is a named tunnel boring machine supplier, a specific route across the Camarinal Sill, a concrete depth figure, and a government-funded design process with real deadlines attached to it. 

Whether or not it opens by 2035, 2040, or later still, the Strait of Gibraltar tunnel has moved from myth into blueprint – and that, on its own, is a genuinely new chapter for one of the oldest transcontinental dreams in modern engineering.

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