£8 billion UK tunnel project to go ahead

Construction is to go ahead on the UK’s tolled Lower Thames Crossing tunnel project. The project is to cost over £8 billion, with much of the financing coming from the private sector.

The Lower Thames Crossing tunnel contract is being handled a joint venture team comprising Bouygues Travaux Publics, Murphy, Balfour Beatty and Skanska. Balfour Beatty will build the roads North of the Thames and Skanska will build the roads in Kent. National Highways awarded the Bouygues Travaux Publics – Murphy Joint Venture the contract to drive the tunnels for the project.

The twin tube tunnels will be driven using TBM technology. However, the project will also be a first for the UK, with no diesel machines being used onsite. All mobile equipment use for the project will have to be either electric or hydrogen powered, to meet reduced emissions targets. This will reduce the impact of construction on the local community and environment and the project will utilise new and emerging low carbon technologies and materials.

The new tunnel link will help reduce the severe congestion that occurs regularly at the Dartford Crossing. One of the tunnels dates back to the 1930s and is too narrow to cope with many large vehicles now in regular use. As a result, traffic has to be halted temporarily for the other tunnel to allow large vehicles to be escorted through. The bridge crossing alongside was opened in the early 1990s and the route now carries significantly higher traffic volumes than it was designed for on a daily basis. Although designed to handle 135,000 vehicles/day, the two tunnels and bridge have to cope with an average of 150,000 vehicles/day. Long delays are common when traffic has to be halted to allow large vehicles through or when there are crashes. 

The Dartford Crossing is a key route for the UK's economy, handling traffic travelling between the Channel ports and the rest of the country. Increasing capacity on this strategic route will boost the economy, as well as providing much-needed jobs during the construction phase.

Ian Edwards, president and CEO of AtkinsRéalis, was present in Oxfordshire for UK chancellor Rachel Reeves’ speech on kickstarting economic growth. He said: “We welcome the decisive action being taken to remove barriers to infrastructure delivery and provide the long-term certainty needed to secure investment into the UK and create the supply chains that will deliver sustainable development across the country.  

“Infrastructure investment can be the catalyst for social opportunities and economic growth in every corner in the UK: the faster infrastructure programmes can pass through planning into delivery, the sooner their full impact on the economy will be felt. 

"Today's announcements reinforce this, like the support for nationally significant projects like Heathrow expansion, Sizewell C and Lower Thames Crossing alongside progress to build regional project pipelines. 

“We look forward to supporting this new phase of infrastructure development, from delivering place-led growth through regional regeneration to the vital infrastructure projects that will power homes and business, connect communities and boost jobs, skills and innovation across the country.”

It is more than three decades since the Lower Thames Crossing project was first mooted. An early plan suggested, at around the same time that the Dartford Bridge opened to traffic, was for a concrete box girder type bridge. This attracted comment at the time, given it would have required the longest single span for this type of bridge to date. There was discussion as to how well the bridge would cope with the high traffic volumes expected over its lifetime, considering that it was pushing the boundaries of concrete box girder technology. There was also criticism of its aesthetics. The proposal for a tunnel link came later but was seen as the best option, despite the increased cost.