The TBMs are being named in honour of the first British astronaut in space, Helen Sharman, and British aviation pioneer Amy Johnson, who was the first female pilot to fly solo from Britain to Australia.

Having the project ready to launch main tunnelling represents a major milestone for the NLE.

David Darcy, Project Director of the Northern Line Extension, said:

‘With our two TBMs now ceremonially named, in the tradition adopted across the tunnelling world, we will follow their progress in a ‘personal’ way. Helen will bore the 2.6kms southbound running tunnel to Kennington Park; Amy will bore the 2.4kms northbound tunnel to Kennington Green. We will ensure that these two majestic ‘ladies’ are thoroughly cared for on their very important journeys. We wish Helen and Amy bon voyage!

It is a particular delight that the naming of Helen and Amy has been through the involvement of local school children. We will continue to put special emphasis on involvement of the local communities as we go through with the execution of this exciting project, always encouraging people of all ages into our industry.’

Mark Wild, Managing Director of London Underground, said: “This is a significant moment in the history of London Underground as we prepare to start tunnelling to create the first extension to our historic Tube network for nearly two decades. The Northern Line Extension will bring Battersea and surrounding areas to within 15 minutes of the West End and City. It will also help us to support jobs, homes and growth in this part of south London, help keep pace with the Capital’s rapidly rising population, and is creating jobs through the supply chain across the UK.”