The incredible new ‘twin box’ that will transform a major UK motorway | United Kingdom | News

A major milestone has been reached in the construction of HS2 as work on a 300 meter bridge is due to begin.

HS2 engineers have completed essential preparation work on a section of the M42, finishing the work five hours ahead of schedule.

Construction work will now begin on the 300m bridge structure which will carry the high-speed railway over Britain’s main motorway.

The construction method will use hollow building blocks to create a ‘double box’ structure which will reduce construction time and reduce disruption to road users.

Over the course of two weekend closures, the engineering team prepared the area for construction by removing pre-existing concrete foundations, installing underground conduits and creating a safe work zone in the median from the highway.

Once built, the rectangular structure of the M42 motorway will be 300 meters long and will allow the high speed line to pass through a 130 meter stretch of the M42 between junctions six and seven near the Birmingham NEC.

The structure will be built using a modular construction method that reduces the need for lengthy highway closures, minimizing disruption to road users.

It involves the assembly of giant building blocks that are manufactured off-site and transported to land near the highway.

The structure is expected to be completed in early 2027. In collaboration with National Roads, HS2 will build the structure in place whilst keeping three lanes of carriageway open on the M42, with a 50mph speed limit in place.

Doug Barnett, senior project manager at HS2 Ltd, said: “I congratulate our site team who worked through the night to complete these essential works, allowing the motorway to reopen five hours earlier than planned.

“Following this first phase of work, we can now start building the existing structure from scratch.

“We have prioritized a modular, self-supporting construction method because it avoids any long-term highway closures and reduces the overall construction time, while minimizing disruption.”

HS2 and its main civil engineering contractor for the West Midlands, Balfour Beatty VINCI (BBV), will continue to work in partnership with National Highways as work begins.

At peak construction, a dedicated workforce of 150 will support the complex operation, also creating jobs in the region.

Oliver Shore, project director at Balfour Beatty VINCI, said: “Now that we have completed essential preparation works on a section of the M42, we are ready to begin construction of this double box structure which will carry HS2 trains on the highway.

“Using a modular construction method, this impressive structure will be built into position to minimize disruption to road users.”

David Patmore, National Highways Network Planner, added: “It is crucial for us to keep traffic flowing and we are doing everything we can to ensure people’s movements on our roads are as smooth as possible.

“When we need to carry out large and significant works like this, we work closely with partners like HS2 to ensure disruption is kept to a minimum.

“We will continue to work closely with our partners to reduce the impact of the works on our roads and would like to thank road users and local communities for their patience.”

HS2 services will run between London and the West Midlands on a dedicated high-speed line before reaching destinations further north via the existing West Coast Main Line.