The new high-capacity Milan-Genoa line is largely an underground route. Starting from Genoa, the first section, the so-called Valico Tunnel, develops 27 kilometres into the tunnel, making it Italy's longest underground railway route. In reality, if all the secondary line interconnections are also considered, the project involves building 90 kilometres of tunnels.

Most of this journey is made underground. That is why the excavations are a central part of the work. Compared to the total 90 kilometers of tunnels built, 28 of these were excavated with TBMs. The remaining 62 using traditional methods. During the excavation phases, the complexity is twofold: on one hand, the use of sophisticated excavation techniques, specific to the geological features of the mountain; on the other, managing the huge volumes of spoil (the loose earth and the rocky fragments from the excavation works).

In the first episode of HowWebuild - Webuild's tech video series dedicated to the Terzo Valico project - we discover together the traditional excavation techniques of a large infrastructure, which will allow trains to travel at a maximum speed of 250 km / h, crossing the provinces of Genoa and Alessandria and affecting 12 municipalities until reaching Milan.