Europe’s largest-diameter vertical shaft sinking machine has been fired up in Tilbury as Ferrovial BEMO JV begins sinking the first access shaft for National Grid’s new Thames power tunnel.
Named Verena, after pioneering mechanical engineer Verena Holmes, the German-built machine marks the start of major works on the £230m Grain to Tilbury upgrade – a central strand of the Great Grid Upgrade.
The 2.2km, 400kV cable tunnel will replace the ageing 1960s Thames Cable Tunnel between Tilbury and Gravesend, which has reached the end of its working life.
Ferrovial BEMO JV will deliver the twin-shaft scheme, beginning with a 15m internal diameter, 48m-deep structure now being sunk from the Tilbury site. A second matching shaft will follow at Gravesend.
Verena is the largest VSM ever supplied by tunnelling machine maker Herrenknecht and the biggest of its type in Europe.
The system is fully operated from the surface, removing the need for operatives to enter the shaft and allowing excavation to proceed inside a water-filled environment.
This cuts out the requirement for groundwater lowering or treatment and helps keep progress steady through mixed geology.
National Grid project director Mark Farmer said the launch marks a major milestone for the Thames power link renewal.
Ferrovial BEMO JV’s project director Borja Trashorras said using Europe’s widest VSM boosts safety, efficiency and environmental performance on the challenging shaft build.
The tunnel drive and remaining shaft works will continue through 2026 as the upgrade pushes on to strengthen grid resilience and unlock more home-grown renewable power across the south-east.
