Installation of large and small caissons continues as development of offshore superstructure progresses

Concrete produced directly offshore: a floating factory supporting the works

GENOA, May 22, 2026 – A new milestone has been reached in the construction of the New Genoa Breakwater: the 21st caisson has been installed offshore the Ligurian port city. The project is being carried out by the PerGenova Breakwater Consortium, led by Webuild, on behalf of the Western Ligurian Sea Port Authority.

This caisson belongs to the large-size category: 67 metres long, 30 metres wide, and nearly 34 metres high, taller than a 10-storey building. It is one of the prefabricated elements forming the structural backbone of the new barrier, whose installation requires highly complex technical operations in open water.

Working at sea means operating under constantly changing conditions, without stable surfaces and with the continuous motion of waves. Despite all of this, all phases—even the most delicate—are managed with continuous quality monitoring of the material during pumping, while ensuring high standards of safety and precision.

The mega caissons are built at a dedicated yard in Vado Ligure, where Tronds Barge 33 is deployed—a semi-submersible barge 110 metres long and 45 metres wide. This is a highly specialised platform capable of submerging up to 20 metres below sea level, allowing operations to be carried out under more stable conditions and facilitating the construction and launching of the caissons, even in the complex marine environment.

Alongside the installation of the caissons for the base, work on the offshore superstructure is also progressing with coordination among the different components of the project. A particularly innovative aspect concerns the production of concrete for the sealing of the caissons, which takes place directly at sea thanks to a dual batching plant installed on a floating barge operating about 800 metres from the coast. In fact, it is a real offshore factory: during the day it produces concrete on site, while in the evening it returns to port to load more raw materials.

The New Genoa Breakwater is a strategic project aimed at strengthening the competitive position of the Port of Genoa and adapting the port system to new dynamics in international maritime traffic. Together with the Terzo Valico dei Giovi–Genoa Node projectp, also carried out by Webuild, it is set to ensure a central role for the Ligurian port in Northern Italy’s and Europe’s trade flows.