The delivery of Britain’s new high-speed railway has taken another major step forward after tunnelling teams successfully broke through into the HS2 Old Oak Common station box, completing the excavation of 100,000 tonnes of material, equivalent to the weight of around 14,000 double-decker London buses.
The breakthrough establishes a critical connection between what will become London’s first HS2 station and the wider high-speed network. Once operational, passengers will be able to travel the 140-mile route between Old Oak Common and Birmingham Curzon Street in approximately 45 minutes, while HS2 is also expected to more than double peak-time rail capacity between London and Birmingham.
Work on the twin tunnel sections began from HS2’s Victoria Road crossover box in May 2024. Unlike the majority of HS2’s tunnels, which have been constructed using tunnel boring machines (TBMs), these two 360-metre-long sections were mined entirely through London clay using tunnel excavators before being lined with 30,000m³ of sprayed concrete.
The milestone comes as HS2 continues to make progress across its route. Deep-bore tunnelling between London and Birmingham has now been completed, while more than 80% of the programme’s major structures are either under construction or already finished. During 2025/26, HS2 Ltd delivered more than 10% additional construction activity against plan and achieved six major milestones ahead of schedule.
Old Oak Common is set to become one of the UK’s most strategically important transport interchanges, bringing together HS2 services with the Great Western Main Line, the Elizabeth line and Heathrow Express. The station is expected to provide significant economic benefits for London, the West Midlands and regions beyond through enhanced connectivity and capacity.
The Rail Minister, Lord Hendy, said:
“This is a major milestone for HS2, bringing us a step closer to delivering a world-class transport hub at Old Oak Common and connecting London to Britain’s new high-speed railway.
“HS2 will provide much-needed rail capacity, create space for more reliable services across the wider network and help unlock economic growth, homes and jobs in west London, the West Midlands and beyond.”
The breakthrough, along with that of the northbound tunnel in October, employed an innovative construction technique not previously used on HS2. Engineers cut the tunnel’s dividing wall into sections before pushing the blocks back into the completed tunnel behind, in a process likened to removing pieces from a giant game of Jenga.
HS2 Ltd chief executive Mark Wild said:
“I pay tribute to all those who achieved, and safely delivered, the breakthrough into the Old Oak Common station box. This is a key milestone for the HS2 programme and helps bring us a step closer to achieving our challenging ambition of delivering the railway from Old Oak Common to Birmingham Curzon Street by 2037, or earlier.
“We are now in the final stages of a fundamental reset of the entire HS2 programme to deliver the line safely and efficiently between London the West Midlands at the lowest reasonable cost. The prize of our endeavour will be a new high-speed railway for the Great British Railways network, delivering much needed capacity and driving local regeneration. The new HS2 station at Old Oak Common is set to boost the local economy by £10 billion over the next decade.”
The engineering approach was driven by the tunnels’ changing geometry, with the alignment narrowing from two tracks to a single track between the crossover box and the station approach.
All 100,000 tonnes of excavated material have been transported to reuse projects elsewhere in the UK, supporting wider sustainability objectives.
With the breakthrough complete, an uninterrupted 8.8-mile link has now been established between Old Oak Common station and the West Ruislip tunnel portal on the north-western edge of the capital.
Skanska Costain STRABAG Operations Managing Director David Hannon said:
"Our breakthrough into the Old Oak Common station box is a significant milestone for the project.
“This achievement is a credit to the teamwork and dedication of everyone involved, from those working deep underground to those supporting on the surface. We will continue to deliver our work with safety and productivity at the heart of everything we do.”
Meanwhile, the two giant tunnel boring machines launched from the eastern end of Old Oak Common station box at the start of 2026 continue their 4.5-mile drive towards HS2’s future London terminus at Euston. Both machines are expected to arrive in mid-2027, marking another significant phase in the delivery of the UK’s largest rail infrastructure programme.
Image and video credits: HS2
