The vertical shaft sinking machine (VSM) has started its work at the National Grid’s Tilbury site.

The largest diameter VSM in Europe, the work forms part of the Great Grid Upgrade, the largest overhaul of the electricity grid in generations.

Named “Verena”, after Verena Holmes, a pioneering British mechanical engineer, the VSM will enable the project to replace the existing 1960s Thames Cable Tunnel between Tilbury and Gravesend to reach the next stage. This, in turn, is a part of the larger upgrade to the country's electricity network.

Ferrovial BEMO JV has been awarded the contract to build a 2.2km-long high-voltage (400kV) cable tunnel, with the VSM designed and built by Herrenknecht. This purpose-built approach represents a significant innovation for UK shaft construction, offering improved safety, speed, and environmental performance.

Verena has now been deployed to construct the 15m internal diameter shaft at Tilbury, reaching a depth of just over 48 metres. Once complete, a second shaft will be constructed at the project’s Gravesend site.

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.”

---