At 5:28am this morning, the first paying passengers caught their first train on the Northern line extension at Battersea.
The extension, which has been under construction since November 2015, links the new developments at Battersea Power Station with the Charing Cross branch of the Northern line, with an intermediate station at Nine Elms. To reduce crowding at Kennington as more people will be swapping between the Bank and Charing Cross branches, four additional side passages were built.
It’s the first major extension of the London Underground this century, and while pedants will argue that the extension to Heathrow T5 in 2008 counts, that was one stop and only within the airport, so it’s not “major”, in the sense of two stations open to the wider public.
The two running tunnels link in with the Kennington Loop and then run via Nine Elms to Battersea, plus two overrun tunnels beyond the station. Just outside Battersea station there is also a large crossover cavern to allow trains to use either platform at the end of the line.
During construction, the spoil from the train tunnels and Battersea site were taken by conveyor belt to the river to be carried away by barge to a waste landfill site next to Tilbury power station. The muck carried there has been used to landscape the area back into arable farmland and create a new riverside path.
Most of the spoil from Nine Elms was also carried through the railway tunnels to Battersea to be disposed of the same way, which required the new tube station at Battersea to be given a temporary waste removal license.
Construction of the Northern line extension was delayed though.
When the groundbreaking ceremony took place in November 2015, it was expected that the extension would open by December 2020. However, a major change to the plans for the oversite development above the station at Battersea caused a significant delay and pushed up the cost of the station build. The main issue was that they had to redesign a lot of the load-bearing structures to cope with the much heavier than expected blocks of flats above.
Due to the station delays, the tunnel boring machines, due to leave in the summer of 2016 actually left in April 2017, although they then completed the tunnelling in the six months that was expected.
Fit-out and completing the stations have taken the rest of the time since 2017, along with a lot of testing.
The signalling system being used on the extension is also slightly different from the rest of the Northern line. When the Northern line was upgraded to Thales supplied Communications Based Train Control (CBTC) in 2013/14 they used a fiber loop based system in the tunnels to track the location of trains as that had been ordered back in 2010. Since then the technology has advanced to a radio-based system, as is being used on the sub-surface upgrade at the moment. At some point in the future, the older fiber-based system will need replacing when it’s no longer supported, so it made sense to install its radio-based replacement into the extension. The trains and signals all behave the same, but the extension is ready for the next generation of signalling systems.
Funding the Northern line extension
The line has been funded entirely locally without any central government contributions. The specific mechanism is that the Public Works Loan Board provided a £1 billion interest-bearing loan, which is repaid by higher local business rates around the new tube line extension and contributions from all the housing developments going up across the wider Vauxhall Nine Elms Battersea (VNEB) Opportunity Area.
That will cover around three-quarters of the cost. The rest comes from the developer contributions that would normally go to the local council, but will instead be used to fund the Northern line extension. From their share of developer contributions, Wandsworth council will provide £259m, including £200m from the Battersea Power Station site and £59m from other sites, and Lambeth council provides £7.3m.
The funding deal lasts for 25 years, with an option for a 5-year extension if needed. If the debt is still not paid back after 30 years, then the outstanding amount will be repaid by London taxpayers through the Greater London Authority (GLA).
The project costs also rose from £1 billion to an expected cost in the region of £1.1 billion. Due to uncertainty in Jan 2016 about the engineering changes being needed at Battersea, it was agreed to increase the approval for the project to £1.26 billion. The project has been delivered on budget at £1.1 billion.
In Jan 2019, it was confirmed that the opening of the extension would be delayed from late 2020 until Autumn 2021, and even despite the pandemic lockdown and the subsequent impact on working conditions, they did manage to hit the new deadline.
So this morning, the new line opened, and what awaits passengers?
Battersea Power Station
A new terminus for the Northern line, this is a station on three levels, with a modest-sized entrance leading down to a vast open space for the ticket hall level, then down two separate banks of escalators to a rather more modest platform space.
Built mainly to serve the huge development that’s been turning the derelict land around Battersea Power Station into housing, the station will have two entrances, of which only one is opening initially, and that’s the one closest to the main road. A second entrance that ties in closer with unbuilt parts of the development will open later.
A rather dramatic angular ceiling, which the builders noted was as difficult to assemble as it looks like it would have been is flooding the entrance with a lot of daylight down the escalator shaft to the lower ticket hall.
Here a double-width space opens up with a very wide ticket gateline (12 standard and four wide gates) along the middle leading to the platforms. On the unpaid side, there are, as at Canary Wharf, spaces set aside for retail shops (aka, coffee shops), and a number of cash machines.
Running along the two long walls is a work of art, by Alexandre da Cunha, a series of old-fashioned advertising rotators that are painted blocks of colour and slowly rotate throughout the day presenting an ever changing appearance. It’s a rather nice effect to be standing there the moment the colour swap ripples along the width of the station, which happens every few minutes.
Along the ceiling is a gently coffered concrete decoration that helps to reduce the impact of so much ceiling space.
Leading from the ticket gateline, two double sets of escalators lead down to the platform level. The decorative effect is simple, mainly metal cladding and dark walls with some gold ribbing along the ceiling. The main show is the ticket hall, not the platforms.
The station at Nine Elms is arguably the one that will have the biggest impact on pre-existing residents as it’s being built in an area that was already densely residential, and the area is now a mix of some new build and a lot of older blocks.
The station is also a perfect reflection of the changes in how people travel in London, as it sits on land that was once given over to motorists – an old car park.
The entrance is also larger than at Battersea, having five large doorways and then straight into the ticket barrier and down to the platforms. There are 9 standard ticket gates plus two wide gates. A nice touch is that there are a couple of seats next to the wide gate closest to the lift.
Three sets of escalators lead down a large box to the platform level, and a very wide space has been carved out of the ground down here. As it’s the Northern line, there are no platform edge doors here, although there is passive provision in the design should they need to be added later.
The design is plain concrete columns and the overhead bracing shows the structure, with a gold ribbed ceiling above. Some will complain about the plain design, but add decoration and just as many will then complain about the colour or the pattern chosen.
A plan for some artwork in the upper ticket hall was later cancelled.
The overall effect is though of a spacious platform space which is a pleasing change from the small tunnels that most Northern line stations have, leading up to a large bright ticket hall, which has hints of Charles Holden about the way the large windows frame the top of the box letting loads of light flood into the station.
A few things to look out for
The staff cabins in the stations have Victoria line moquette seats.
Some of the maps have little stickers over them ready to be removed when the Elizabeth line opens.
Photographers might like the reflective colour effect you can from the platform walls at Battersea while there’s a tube train in the station.
Two new ventilation shafts have been added to the Northern line at Kennington Park and Kennington Green.
People who are used to catching an empty train at Kennington will now find it’s got passengers from Battersea and Nine Elms on board already.
There is a very cold blast of air when the trains arrive at Nine Elms, thanks to tunnelling through cold soil and the two ventilation shafts. This may help to reduce the heat in the Northern line slightly across the rest of the line by cooling the trains as they pass through the extension.
New tube maps have been issued.
When the refurbished platforms at Whitechapel station opened a few weeks ago it was confirmed that it has the widest platform on the London Underground, but Nine Elms is also very wide. Has Whitechapel lost its crown already?
The width of Nine Elms was confirmed as being 17.6 metres wide, so armed with a tape measure, a visit to Whitechapel station was in order to check its width. And it turns out that Whitechapel is about 20.9 metres wide, so it retains the title of the widest platform on the London Underground. Sorry Nine Elms.