Cable tunnel works
Replacing the Thames Tunnel
The existing tunnel between Tilbury in Thurrock and Gravesend in Gravesham needs replacing as it was built in the 1960s and is coming to the end of its useful life.
The tunnel under the Thames will be 2.2km in length and will take eight months to build.
Introducing Verena, Europe’s biggest Vertical Shaft Sinking Machine
To start work on the tunnel, we first had to build a shaft at Tilbury which was big enough to house the tunnel boring machine. To do this, we used Europe’s biggest Vertical Shaft Sinking Machine. It measures 15m wide and 48m deep. We've just done the same at our Gravesend site.
Introducing Caroline, the Tunnel Boring Machine
Over the next eight months, the Tunnel Boring Machine will work continuously to get the new tunnel built, starting slowly at first – roughly 0.9m per day – until travelling an average of 23m per day.
Naming Caroline and Verena
Over 30 students from local schools were offered a unique opportunity to name the machinery. Taking inspiration from influential women in engineering, the TBM was named after Dame Caroline Haslett and the VSM named in honour of Verena Holmes.
Overhead line works
Our overhead line teams have started a programme of maintenance and upgrades, works began in mid-April 2026 near the Kingsnorth Power Station. Over the next seven months, they’ll make their way along the route making sure the infrastructure is fit for the future.
The Great Grid Upgrade
The Great Grid Upgrade is the largest overhaul of the electricity grid in generations. Our infrastructure projects across England and Wales are helping to connect more renewable energy to your homes and businesses.