Europe's largest-diameter Vertical Shaft Sinking Machine (VSM) has been launched at National Grid's Tilbury site in Essex.

The machine, named Verena after pioneering British mechanical engineer Verena Holmes, is also the largest VSM ever supplied by Herrenknecht. Construction works are being delivered by Ferrovial BEMO JV.

Part of The Great Grid Upgrade, the scheme will replace the 1960s Thames Cable Tunnel between Tilbury and Gravesend, which has reached the end of its operational life. The project is designed to strengthen the UK’s transmission network and help connect more affordable, home-grown renewable energy to households and businesses.

Ferrovial BEMO JV has been appointed to construct a 2.2km high-voltage (400kV) cable tunnel, with the VSM designed and built by Herrenknecht AG. The bespoke method introduces a significant innovation for UK shaft construction, improving safety, speed and environmental performance.

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At Tilbury, the VSM is being used to build a 15m internal diameter shaft to a depth of just over 48 metres. A second shaft will then be sunk on the project’s Gravesend site.

Operated remotely from the surface, the VSM removes the need for personnel to enter the shaft during construction. Its cutting drum works in a water-filled shaft, avoiding groundwater lowering or treatment, while the shaft is carefully lowered from the surface as excavation progresses—enabling safe, efficient progress through challenging ground conditions.

Mark Farmer, Project Director for National Grid, said: "The Grain to Tilbury project is helping to future-proof the UK's electricity network. The launch of the Vertical Shaft Sinking Machine marks a major milestone for the project. Through collaboration and innovation, this technology is helping to deliver resilient infrastructure under the Thames, securing reliable electricity for the decades ahead."

Borja Trashorras, Project Director, Ferrovial BEMO JV, said: "Launching Europe's largest diameter Vertical Shaft Sinking Machine at Tilbury is a milestone achievement for our team and for UK infrastructure. This technology allows us to deliver the Grain to Tilbury project with enhanced safety, efficiency, and environmental performance. We're proud to be working in partnership with National Grid and Herrenknecht to bring this pioneering solution to life, helping to future-proof the electricity network for generations to come."