Bouygues Travaux Publics Murphy Joint Venture has started procurement for one of Europe’s largest tunnel boring machines (TBM), marking a key milestone on the £10bn Lower Thames Crossing. The JV, appointed as tunnelling partner to National Highways, is seeking bids to design and build the machine that will drive two three-lane road tunnels beneath the River Thames between Kent and Essex.
The TBM will have a diameter of 16.4 metres and excavate more than 4km at depths of up to 60 metres. Its procurement follows confirmation in the Budget of £891m in public funding for the scheme.
Construction of the crossing is due to begin in 2026, with tunnelling scheduled to start in 2028. National Highways aims to keep the programme on track for an opening in the early 2030s.
To cut embodied carbon, the project team plans to use a single TBM to bore both the northbound and southbound tunnels. Concrete segments for the tunnel lining will be manufactured at a temporary casting facility near the northern tunnel entrance in Tilbury, Essex.
Work on the TBM launch chamber is expected to begin next summer. The 110-metre-long, 26-metre-deep structure will be buried beneath Tilbury Fields, a new landscaped park overlooking the Thames.
Delivered by National Highways, the Lower Thames Crossing will become the UK’s longest road tunnel and one of the widest of its type globally. The new link is intended to ease chronic congestion at the Dartford Crossing and improve freight flows between ports in the South East, the Midlands and the North.
Roads and Buses Minister Simon Lightwood described the TBM procurement as a “major step forward” for a scheme he said would unlock “jobs, growth and opportunity”. Matt Palmer, executive director for the Lower Thames Crossing at National Highways, said the TBM order would support the project’s timetable for opening in the early 2030s.
Planning consent for the Lower Thames Crossing was granted in March 2025, clearing the way for major procurement and enabling works to proceed.
