HS2 Ltd. has announced the completion of the foundation slab for its new high-speed station at Old Oak Common in London, marking a significant step forward in the project.
The 850-metre-long underground station base, designed to accommodate six high-speed platforms, required 76,000 cubic metres of concrete and 17,000 tonnes of reinforced steel. The 45,000 square metre base slab, equivalent to more than six football pitches, reaches nearly two metres thick at its deepest point and was constructed through 91 separate concrete pours.
Balfour Beatty Vinci SYSTRA joint venture (BBVS) is constructing the station. At peak construction, the base slab works employed up to 50 steel fixers and 20 joiners, supported by a team of engineers.
HS2’s Project Client for Old Oak Common, Peter Gow, said: “Completing the base slab of the underground station box is a key milestone in building HS2’s new super hub station in West London. This is the final stage in completing the foundations for the high-speed station, and will be where HS2 tracks are laid, platforms are constructed and the station building and roof and built above.
“At Old Oak Common we are making significant progress in building this state of the art, environmentally friendly, transport hub which will be a key part of the HS2 route.”
The excavation of the station box, completed in summer 2024 by subcontractor Expanded, involved the removal of 1.3 million tonnes of London clay. The base slab construction involved installing blinding, shingle layers for drainage, and a geotextile mat, followed by a 1.85-metre-high reinforcement layer and the concrete pour.
London Concrete, part of the Holcim Group, supplied the concrete from a dedicated on-site batching plant. Over 90% of the concrete was manufactured on site, reducing lorry movements and CO2 emissions. The use of low-carbon ECOPact concrete, along with innovative design, has contributed to the station’s BREEAM Outstanding rating, placing it in the top 1% of environmentally friendly buildings in the UK.
Steve O’Sullivan, Project Director for Balfour Beatty VINCI SYSTRA, joint venture said: “With the completion of the base slab, we have achieved another significant milestone at Old Oak Common. In less than two years, we have carried out 91 concrete pours of between 600m3 and 1 000m3 each. Logistically, this has been a huge undertaking, requiring detailed planning and collaboration between HS2, Balfour Beatty VINCI SYSTRA and our supply chain partners.
“This latest step will enable us to progress to the next phase of works, with construction of the high-speed platforms already underway”.
Work is now in progress on the six HS2 service platforms, with wall frameworks being installed for concrete pouring. The high-speed platform slabs are being manufactured by Explore in Worksop, with installation beginning this spring. The team is also working above the base slab to construct the ground floor level of the station.
Tunnelling work connecting the station to the HS2 network is being carried out by HS2’s London tunnels contractor, Skanska Costain STRABAG JV. In the eastern section of the box, the team is preparing to launch two giant tunnelling machines towards Euston. In the western section, the tunnel will be excavated using the sprayed concrete lining method.
Old Oak Common, located on land previously used for railway depots, will become one of the UK’s best-connected stations. The site, between the Elizabeth Line depot and the realigned Great Western Main Line, will allow Elizabeth Line, Great Western Main Line, and Heathrow Express trains to call at the station.
As Britain celebrates 200 years of railways, the progress at Old Oak Common represents an important part of the nation’s railway future.
