Santa Barbara, the Light in Underground Infrastructure Development with TBMs

On 4 December, in dozens of underground construction sites across Italy and around the world, a small altar, a bouquet of flowers, a statue or a time-worn image return to centre stage. It is Saint Barbara, the protector of miners, tunnel workers and explosives experts, a figure who has accompanied for centuries the men and women who work in the bowels of the earth.

The tradition was born in Europe between the nineteenth and twentieth centuries, when miners invoked the young Christian martyr as guardian against explosions, collapses and sudden gases. With the arrival of major infrastructure projects in the twentieth century, Saint Barbara also became the spiritual reference point for tunneling: metro lines, railways, Alpine underground tunnels. A secular and religious celebration at once, an identity ritual that honours the strength and vulnerability of an extreme profession.

Even today, across Webuild’s construction sites, the feast of Saint Barbara is a special day. This year it is even more meaningful because the celebration coincided with the 75th anniversary of the founding of Seli Overseas, the Webuild-owned company specializing in underground excavation projects around the world.

Amid shifts and the strict routines of excavation fronts, the recurrence becomes a moment to pause, come together, and pay tribute to a profession requiring skill, courage and solidarity.

This happens at the Terzo Valico dei Giovi, where the Tunnel Boring Machines (TBMs) are excavating the major railway corridor between Piedmont and Liguria. It happens in Naples, at the new Parco San Paolo station on Line 7, where engineers and workers operate beneath layers of millenary history. And it happens in all ongoing underground construction projects: a simple, often informal gesture that unites workforces of different languages and cultures under the same symbol.

And so, from Italy to Canada, from the United States to Australia, on December 4th, in Webuild’s construction sites the feast of Saint Barbara was celebrated — not merely a recurrence but a bridge between an ancient trade and the engineering challenges of the twenty-first century. A way to remember that, even in the era of TBMs and automation, it is always people — with their experience, courage and stories — who keep the heart of major projects beating.

For those who work on underground construction sites, Saint Barbara remains a symbol that survives progress. No longer merely an act of faith, but a moment to recall the value of safety, shared responsibility, and the need to remain vigilant at every stage of excavation.

Within tunnelling teams (mechanics, miners, TBM operators, geologists, monitoring technicians), the celebration is a ritual of belonging, a memory renewed each year as the TBMs advance metre after metre, bringing modern and sustainable infrastructure to cities and territories.

Today, safety itself is entrusted to a refined science: geology, seismic monitoring, innovative materials, ventilation systems and, above all, TBMs that transform tunnel boring into a continuous, controlled and protected process.

For Webuild, tunnelling is an industrial frontier in which the Group has developed a global leadership role, deploying some of the world’s largest and most sophisticated TBMs. Each machine is a steel giant over one hundred metres long, capable of advancing, installing segments, monitoring pressures, interacting with safety systems and ensuring the protection of the teams.

The constellation of Webuild’s underground construction sites today forms a global atlas of contemporary tunnelling. The Group now has around 60 TBMs either operational or on order, distributed across Europe, the Americas and Oceania.

Italy represents the nerve centre of this underground network, with around 40 machines engaged in infrastructure projects such as new high-speed railways, metro lines and hydraulic systems. These are the TBMs advancing beneath cities and mountains, from the excavation of the Terzo Valico to the sections of the Naples–Bari High Speed/High Capacity line, from Sicilian tunnels to the shafts and stations of Rome’s Metro C.

Beyond national borders, Webuild is active in some of the most complex underground construction sites on the planet, from France to Canada, from the United States to Australia, and as far as Peru, Romania and Austria. The TBMs operating in these worksites form a global underground network that crosses continents, geological environments and cultures.

It is a technological heritage that reflects Webuild’s leadership in the underground infrastructure development world and its ability to tackle, metre after metre, some of the most demanding engineering challenges of our time.