Going further on the Northern line

After six years of construction, and our involvement as lead designer, the 3km extension to the Charing Cross branch of London Underground’s Northern line completed in 2021. Featuring the first new stations on the line for 80 years, at Nine Elms and Battersea, the £1.1bn extension is critical to the ongoing regeneration of the area around Battersea power station. London mayor Sadiq Khan said of the new stations: “They will hugely improve connectivity… and play a major part in the capital’s recovery from the pandemic by supporting thousands of new jobs, homes and businesses.” A £7.9bn boost to London’s economy was forecast, with 25,000 new jobs. Extending transport networks in congested urban environments is a challenge, but our adoption of advanced methodologies smoothed the way. For instance, applying design for manufacture and assembly (DfMA) enabled us to free up space during construction, through offsite manufactured components. Meanwhile digital tools helped us minimise the impact on local communities, for example our in-house ReVERB software modelled train vibrations and noise levels. Moreover, by reducing the tunnel lining thickness following geological reassessment, we helped save 1500t of carbon emissions – with carbon reduced in the secant piling too, by using concrete with a high proportion of cement alternatives.