Full steam ahead: Tunnelling for the £1.2bn Northern Line extension starts in March

Rebecca Smith
The cost of the Northern line extension is expected to be up to £1.2bn
The cost of the Northern line extension is expected to be up to £1.2bn (Source: TfL)

The first extension to the Tube network since the Jubilee line in the late '90s kicks off in March, as tunnelling gets underway to branch out the Northern line.

Sadiq Khan has announced that tunnelling will get underway to create the £1.2bn extension of the line between Kennington and Battersea.

Two 650-tonne boring machines (each the length of a football pitch just FYI) from French firm NFM Technologies will create two 3.2km underground tunnels to extend the Charing Cross branch of the Northern line from Kennington to Battersea, via Nine Elms.

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One of the boring machines soon to be in action
One of the boring machines soon to be in action (Source: TfL)

The machines have also been named, thanks to a vote by local school children, so Helen and Amy (in a nod to astronaut Helen Sharman and aviation pioneer Amy Johnson) will get tunnelling in March.

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The mayor said: "It’s great news that we are going to begin tunnelling for the Northern line extension. Extending the line to Nine Elms and Battersea is going to be a real boost to south London, with the improved transport link helping to provide thousands of homes and jobs for Londoners."

How the Northern line will be extended
How the Northern line will be extended (Source: TfL)

The extension will support around 25,000 new jobs and more than 20,000 new homes. Two new stations are also being created – one at the Battersea Power Station redevelopment and another at Nine Elms.

£1bn in funding for the extension will be provided by the private sector through a package agreed by Battersea Power Station, Wandsworth and Lambeth councils, the mayor and government.

Mark Wild, managing director of London underground, said the extension "will bring Battersea and surrounding areas to within 15 minutes of the West End and City".

Timeline of the Northern line extension:

  • 2017 - Main tunnelling takes place
  • 2019 - Station fit out
  • 2020 - Testing and commissioning; extension in operation