Tunnelling starts to extend the Northern line to Battersea
Published: Thursday 13th April 17
The Northern Line Extension to Battersea has moved a significant step forward as the first of two giant tunnel boring machines began the 3.2km tunnelling journey to extend the line from Kennington.
Helen has now set off to create the first of the underground tunnels that will extend the Charing Cross branch of the Northern line from Kennington. Amy will follow in around a month.
The extension, targeted for completion in 2020, is the first major Tube line extension since the Jubilee line in the late 1990s.
The Northern Line Extension helped to kick start the regeneration of Nine Elms and Vauxhall which is on course to create around 25,000 new jobs and more than 20,000 new homes. Construction is also boosting the UK economy, supporting around 1,000 jobs, including around 50 apprenticeships.
As well as two new tunnels, two new stations are being created: one at the heart of the Battersea Power Station redevelopment and another at Nine Elms to the east, serving new developments such as the US Embassy and the redevelopment of New Covent Garden Market, as well as existing communities.
As the 100 metre long tunnelling machines advance forward, nearly 20,000 precast concrete segments will be put in place to form rings to line the tunnels. A conveyor system will then take the spoil from the tunnels up to barges on the River Thames. More than 300,000 tonnes of earth will be excavated by Helen and Amy in this way before the spoil is taken by barge to Goshems Farm in East Tilbury, Essex where it will be used to create arable farmland.
Each machine is capable of tunnelling up to 30 metres a day with teams of around 50 people operating them. Tunnelling is expected to take around six months to complete.
According to tunnelling tradition, tunnel boring machines cannot start work until given a name. Following a vote by local school children, including students from Griffin Primary, the machines were named in honour of the first British astronaut, Helen Sharman, and British aviation pioneer, Amy Johnson, who was the first female pilot to fly solo from Britain to Australia.
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