The existing Thames Cable Tunnel between Tilbury, Thurrock, and Gravesend, Gravesham is over 60 years old and is coming to the end of its useful life hence the need for its replacement. 

The project involves the replacement of the existing 1960’s Thames Cable Tunnel between Tilbury, Thurrock, and Gravesend, Gravesham.

Tunnel Replacement 

National Grid will be required to carry out an Environmental Impact Assessment to demonstrate the works will not adversely impact the local environment.   

The tunnel will be 2.3 kilometres in length and will run beneath the Thames between Tilbury and Gravesend. This will require planning permission, along with the headhouses and overhead line alterations, to be granted under the Town and Country Planning Act by both Gravesham and Thurrock Council.

Headhouses and cable sealing ends

Two headhouses, and sealing end compounds, will be required as part of the development, at either end of the tunnel at Gravesend and Tilbury. This infrastructure is required to connect the existing overhead line route to the new cable in the tunnel, and to the rest of the electricity network. It will also be necessary that we later deliver and install a new pylon at both the Gravesend and Tilbury headhouse sites, and remove three existing pylons at Tilbury. This is planned for 2027/2028.

Overhead line refurbishment 

The scheme also includes the full refurbishment of the existing overhead line between Tilbury, Kingsnorth, and the Isle of Grain. As this is existing infrastructure, it is not included as part of this Town and Country Planning Act application, and further engagement will take place when this work is being prepared. 

Project timeline