Webuild: seven hydromills deployed for new Pedemontana Lombarda Highway

More than 26 kilometres of highway under construction to strengthen connections between Como, Varese, Milan, Monza and Brianza, and Bergamo

Milan, September 2, 2026 – Seven hydromills along the route: this is the configuration, among the most impressive being deployed on a major infrastructure project in Italy. Work being done by a consortium led by Webuild together with Pizzarotti on behalf of Autostrada Pedemontana Lombarda is progressing according to schedule on Sections B2 and C of the Pedemontana Lombarda Highway, a strategic infrastructure project for Northern Italy.

The project will strengthen connections among Como, Varese, Milan, Monza and Brianza, and Bergamo with more than 26 kilometres of new highway infrastructure between Lentate sul Seveso and the interchange with Milan’s A51 Eastern Ring Road at Usmate Velate, one of Europe’s most densely urbanised and industrial regions. Once completed, the New Pedemontana Lombarda Highway will ease traffic along the existing network and improve the efficiency of road transport for both people and goods.

Approximately 85 percent of the route will run through trenches or tunnels, reducing noise and minimising the impact on the urban fabric while creating space for new green areas and public spaces along the corridor. A key phase of the project is the construction of diaphragm walls, the structural elements forming the underground walls of future cut-and-cover tunnels. This is a complex operation that hydromills can significantly accelerate. Standing more than 24 metres high and weighing over 400 tonnes, these machines drill deep into the most resistant ground conditions, supporting the excavation walls with slurry while extracting and transporting excavated material to the surface. The productivity gain compared with traditional excavation methods is substantial: from an average of 3 to 4 diaphragm panels per week to 3 to 4 per day for each hydromill, reaching depths of up to 40 metres. At full capacity, the seven machines will be able to construct approximately 130 diaphragm panels in a single week.

The technology is at the core of the so-called “Milan Method”, which will be used, for example, for the Desio and Macherio tunnels. With this approach, the diaphragm walls and tunnel roof are built first, followed by excavation under it. It is a solution specifically developed for densely populated urban environments, where limiting the impact of construction activities at ground level is a priority.

The New Pedemontana Lombarda Highway is one of 11 infrastructure projects being delivered by Webuild in Northern Italy. These sites collectively employ 11,100 people, directly and indirectly, supported by a supply chain of around 5,000 companies since the start of construction activities.