Cultural links have always run deep between Italy and Sicily, but the Strait of Messina separates them. To reach the volcanic island paradise from mainland Italy and explore its rich 2,500-year-old Greco-Roman history, visitors need to fly out or take the ferry. While this option is romantic and enchanting for those who aren’t concerned with time crunches, it’s also true that it’s a slow trip.

The Strait of Messina suspension bridge is set to transform that 25-minute ferry ride into a road trip that’s done and over in a fraction of the time. Knowing the area as they do, though, curious Italians and Sicilians can’t help wondering exactly what engineering challenges will be posed on a project of this scale. Frankly, they’re not alone in their speculations.

Artists image, circa 2001, of the Stretto di Messina. Source: Stretto di Messina SPA

A record-breaking Sicilian gambit

The Messina Strait, a narrow channel that flows between mainland Italy and Sicily, has strong currents. It’s possible that the shallow — only 90 meters deep in places — channel functions as a funnel between the Tyrrhenian Sea and the Ionian Sea, with Sicily acting as a pressure point between the two bodies of water. Indeed, some of the more dramatic Greek myths about sea tragedies may have been set right here. Homer’s Odyssey comes to mind.

Strangely enough, mythology and engineering have collided in this instance. Tales of sea monsters and the raging maelstrom that was the whirlpool of Charybdise are straight out of the fiction section of the library, not the staid engineering journals expected by consulting bridge designers.

So far, there are fault lines to contend with, as explained by those tales about sea monsters by Greek storytellers. Whirlpools and strong tidal forces are also on display, and then there’s the disdain exhibited by Sicilian locals, too. They don’t want their isolation disturbed or beautiful Mediterranean views obstructed by a bridge, not even if that groundbreaking structure represents an engineering marvel of epic proportions. Perhaps that’s why the project is ratcheting up costs that lay in the neighborhood of $16 billion.

Focusing less on politics and more on engineering solutions

It’s an expensive bridge, one generating reports of a divided Italy. The must-not-name crime family syndicates don’t approve. The same can be said for the local geography and geology. There’s no straightforward construction path, unfortunately. Migrating birds, environmental concerns over sea life habitats, and the disruption of the natural landscape are all factors contributing to the controversy surrounding this project.

As much as all of the above obstacles might hinder the feasibility of a suspension bridge, construction engineers need to rise above them and concentrate on more substantial matters. The rest is best left to environmental consultants, land surveyors and lead civil engineers. A suspension bridge capable of spanning a 3.2 km (2 mile) gap is a massive endeavor.

By connecting Sicily to Italy, a population of 59 million will suddenly have access to a historic and stunningly beautiful island. On the island side, 5 million Sicilians can drive to Rome or Florence, or they can carry on into all of Europe, perhaps into France, the Channel Tunnel and into England.

Earthquake-handling mechanisms are next on the agenda. The support abutments and piers supporting the bridge deck are constructed initially, all the way from Torre Faro in Sicily to Villa San Giovanni in Calabria. The two sides are located at the narrowest point of the Strait, hence the 3.2 km length of the suspension bridge. The loading cables supporting the deck exist partially to absorb and transmit seismic energies so the bridge will withstand earthquakes in a notoriously seismically active region. Just to reinforce this point, Mount Etna, one of the most active volcanoes in the world, resides in Sicily.

Solutions for overcoming multiple engineering hurdles

Although this is the longest suspension bridge to date, there are several other projects that can be referenced by engineers when conducting a feasibility study. The Akashi Kaikyo Bridge links Kobe to the island of Awaji in Japan. It’s built to absorb seismic shock and has a mechanism capable of damping resonant forces. The 1915 Çanakkale Bridge required similarly innovative engineering processes to get off the ground. It connects Asia to Europe, utilizing only two towers.

Of course, supporting the massive spans in a suspension bridge like this means raising the heights of these towers to over 300 meters. The Strait of Messina suspension bridge will likely use a similar approach, as a taller tower height equals longer cable spans and fewer deck-supporting foundations below.

It’s a difficult task, reducing so many real-world factors down to a few mathematical variables, but that’s the challenge accepted by all civil engineers, be it a small construction project or an off-the-scale suspension bridge design like this Italy-to-Sicily architectural marvel. Offsetting winds and sea currents, tall towers and longer cable spans provide a solution; there’s the possibility of tuned mass dampers and other resonant energy balancing systems.

Ultimately, situational engineering is called for in this design. Exploring stiffening girders, sleek aerodynamics and wind-mitigating decks is also crucial. This will need to happen before sound and effective engineering designs can be integrated into the upcoming Strait of Messina suspension bridge, which will debut in the 2030s.

Besides displaying great architectural prowess, Sicilians will (hopefully) embrace the idea of a quick, ferry-free journey to the Italian mainland and leave all the politics behind.