Breakthrough achieved at HS2 London tunnel

The construction of HS2 reached a major milestone on Tuesday, 13th October, when mining teams broke through the tunnel into the box at HS2’s Old Oak Common station. The breakthrough enables Old Oak Common station to connect to the HS2 high-speed line via an 8.8-mile link to its West Ruislip tunnel portal on the capital’s north-western periphery. Workers excavated around 100,000 tonnes of material from the tunnel, about the weight of 14,000 double-decker London buses, and removed it for reuse on other projects across the UK. Once completed, Old Oak Common will be one of the country’s best-connected transport hubs by linking HS2 with the Elizabeth line, Great Western Railway, and the Heathrow Express. Construction of the 360-metre-long tunnels began in 2024 when contractors started work on the crossover box site in Victoria Road. This tunnel is different to other tunnels on HS2, in that it hasn’t been built using huge tunnel boring machines. Instead, tunnel excavators were used to mine through London clay, before the excavated sections were lined with 30,000m3 of sprayed concrete, then travelling formwork used to line them with concrete cast in situ. Because the tunnel’s width narrows from two tracks to one between the crossover box and Old Oak Common station, a special construction method was required. Elsewhere on HS2, all deep bore tunnelling between London and Birmingham has been completed and over 80% of the major structures along the route are either under construction or complete. Progress in 2025/26 was above target, with over 10% more construction than planned, and six major milestones achieved ahead of schedule. “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.” Rail Minister Lord Hendy