National Grid has appointed at Ferrovial BEMO joint venture deliver a new £230m tunnelling contract.
Ferrovial Construction and BEMO (Ferrovial BEMO JV) will deliver the contract - to design and build a 2.2km high voltage cable tunnel under the Thames between Grain and Tilbury.
The existing tunnel was built in 1969 and houses 400 kilovolt (kV) transmission cables as part of National Grid's high voltage transmission network.
Completion of the project, Ferrovial’s first with National Grid, is expected in the first quarter of 2029.
Work will include the construction of a new 2.2km long high voltage (400kv) cable tunnel and includes two 35m deep shafts (15m and 12m diameter respectively), headhouses and Cable Sealing End (CSE) compounds.
One of the solutions to be employed on the scheme is a Vertical Shaft Sinking Machine (VSM), renowned for its reliability and accuracy.
The VSM technology allows for simultaneous excavation and installation of the final lining from the surface, significantly reducing construction time, minimising environmental impact and ensuring the highest level of safety throughout operation.
The VSM can be used under groundwater, making it ideal for the Grain to Tilbury project. This will only be the second time that this method is used in the UK.
The project is part of a broader programme of infrastructure upgrades and reinforcements planned by National Grid as part of The Great Grid Upgrade, the largest overhaul of the UK’s electricity network in generations.
Ferrovial Construction’s track record in complex tunnelling projects in the UK includes the Thames Tideway Tunnel (FLO JV), the Silvertown Tunnel (Riverlinx CJV), Northern Line Extension (FLO JV) and three contracts on the Elizabeth Line (BFK JV) including the longest stretch of tunnel between Royal Oak and Farringdon, as well as Farringdon Station itself.