Milestone Achieved: Vast underground box for west London’s HS2 station completed

Three years after they started digging, a huge underground box for a new railway station in west London that’s wide enough for six platforms is now complete.

This is the future HS2 railway station at Old Oak Common.

HS2’s Station Construction Partner, Balfour Beatty VINCI SYSTRA joint venture (BBVS JV), working with their structures contractor Expanded, completed the excavation with apprentice Miguel Jardim removing the last of the London clay from the box.

Miguel, 19, a civil engineering apprentice from Surrey Quays, southeast London, joined in the excavation at Old Oak Common as the 1,500th apprentice to start a role helping to build HS2.

The excavation was completed section by section within the box, starting from either end and meeting in the middle.

The box is 20 metres deep — roughly as deep as a six-floor block of flats — and a reinforced concrete base slab up to 2m in depth is being poured throughout. 32,000 tonnes of steel rebar, assembled by hand on site, has been used in the box alongside 160 reinforced concrete columns that have been installed inside the outer wall to help support the structure.

During the digging out of the box, the equivalent of 300 Olympic-sized swimming pools of spoil was removed by conveyor belt to a nearby rail hub and then sent to be used for landscaping former industrial sites in Kent, Warwickshire, and Cambridgeshire.

However, some of the London Clay was kept aside and used for a local arts project led by artist Tom James. Local young people are learning to use the clay to make objects and are now making a dinner service of 100 plates and 100 bowls from some of the excavated materials.

Now that the box is completed, they can begin the long task of turning it into a functioning railway station. When completed, the basement box will have six platforms for HS2 trains, and at the surface, another eight platforms for the Elizabeth line, Great Western Mainline services, and the Heathrow Express.

Sam Clark, Head of Delivery for HS2 said: “The tremendous progress made by our construction team to complete the excavation of the box is an exciting milestone for the project as it signals the next phase of construction where high speed platforms will be built, as well as the station building itself.

“HS2’s Old Oak Common station will be transformational for local and regional connectivity and attract huge investment, development and regeneration to the surrounding area.”

While the rest of the station box is being fitted out to become the temporary terminus for the HS2 railway up to Birmingham, they are preparing to pre-install the tunnel boring machines (TBM) to dig the tunnels to Euston.

Those TBMs will be installed at the station’s eastern end and then sealed in place until needed, which will be when the new government decides how to proceed with the Euston station development.