Highways England has invited firms to submit tenders to build the longest road tunnel in Britain which is part of the Lower Thames Crossing project, one of the most ambitious projects in the United Kingdom in decades.

The £2 billion contract is the largest contract in the history of Highways England.

The Tunnelling Journal reported that the Lower Thames Crossing will improve journeys by almost doubling road capacity across the Thames east of London, with 22.9 km (14.3 miles) of new road featuring two 4.3 km long (2.6 mile) tunnels.

Highways England said work on the project could begin in as soon as 18 months.

The Tunnels and Approaches contract includes design and construction of the twin road tunnels under the River Thames. At 16m diameter tunnels will be bored mostly with tunnel boring machines and will be some of the largest bored tunnels in the world. They will also be the longest road tunnels in the UK. The scope also includes the portal buildings, approach roads and the tunnel systems.

Keith Bowers, the Lower Thames Crossing’s Tunnels and Systems Director, added: “This contract is unparalleled in its ambition, and we need the right partner to match that ambition. From our bidders we’re looking for outstanding construction, health, safety and wellbeing performance. We have committed to targets that mean by 2040 nobody will be killed or seriously injured on our roads and motorways, and we need our contractors’ design and delivery to meet that target for our road users and workers.

“We are setting priorities in our contracts that will reward excellence during delivery by offering an enhanced share of cost savings for high performance in areas including health and safety, customer focus, delivery, environment, people and communities and economics.”
The Tunnels and Approaches contract is the first of the three main works contracts to be procured for the scheme, with the Roads North and the A2 M2 contracts expected to be announced early in 2021.

The scheme’s planning application was submitted on Friday 23 October, and the Planning Inspectorate now has 28 days to review the application and decide whether to allow the application to proceed to examination. A decision is expected from the Secretary of State for Transport in 2022, with construction expected to start later that year.
The A303 Stonehenge (Amesbury to Berwick Down), another significant Highways England tunneling scheme, is due to receive a decision on its Development Consent Order application by the Secretary of State for Transport on Nov. 13.