In pictures: £ 1.1bn northern line extension opens to passengers | New
The first extension of the London Underground network of this century opened to passengers at 5.30am this morning.
Northern Line trains now branch off in Kennington, south London, to stop at two new stations designed by Grimshaw, Nine Elms and Battersea Power Station.
The extension was built to provide better travel links to two of London’s largest redevelopment areas, which include the transformation of the listed Battersea Power Station II * into housing.
Residents will now be connected to the West End, the City and North and South London by Tube for the first time.
Built by Laing O’Rourke on a £ 600million contract, the £ 1.1 billion program began construction in 2015.
The two new stations are inspired by other major upgrades of the modern tube, the extension of the Jubilee line and the redevelopment of Westminster station, with enormous underground volumes supported by concrete columns. An architect from Grimshaw told Building the goal was to create airy spaces with a sense of drama.
The new tunnels, which required 20,000 tunnel rings, began construction in March 2017 before breaking through to Kennington Station in a three-day blockade over the Christmas period at the end of the year .
Over 700 barges carrying 850,000 tonnes of mud and spoil from the excavation were shipped from Battersea to Tilbury during the six years of construction.
Despite the pandemic, the line reached its target date – aided by the fact that major civil works had been completed before the start of the first lockdown.
About 1,000 people were on site at the height of construction, although that number was drastically reduced to just 100 when social distancing rules were introduced.
The small team, which had to stay on site for maintenance and safety reasons, then slowly grew into around 400 people to complete the remaining MEP and fit-out work on 24-hour shifts.
Project manager Michael Eddleston said the experience taught the team how to maintain productivity with fewer people.
He said: “Basically it’s about understanding where planning is the critical point, so [teams] could work with all the subcontractors, figure out where they were working that week, then that would highlight the clashes so we could move people to other areas that weren’t as busy.
“It’s that kind of micro-planning that has really helped us become more efficient and keep productivity high. “
Eddleston added that remote meetings on Microsoft Teams also became more efficient, as staff would no longer have to meet in one room, which would speed up administrative tasks such as documenting insurance.
When asked how the project compared to Crossrail, which suffered from multiple delays and budget overruns, Eddleston said the Northern Line Extension had fewer signaling issues.
“Crossrail had a lot more difficulty because you merge three signaling systems to work together whereas at NLE we just leveraged the existing signaling system and extended it, which is a lot less complicated. “
The extension was originally intended to connect to the Victoria Line via nearby Vauxhall station.
These plans were scrapped to avoid too much pressure on the already busy Vauxhall station, with the tunnels connected to the Northern Line instead.
This means Kennington Station is now the center of four converging branches of the Northern Line, but Eddleston said it was unlikely to be expanded in the near future.
Instead, four new cross passages were built at platform level to allow passengers to change trains.
Eddleston said the next big tube upgrade would be more likely to be at Elephant & Castle, although this was mostly funded by the private sector.