As part of the £1.2 billion northern line extension, two tunnel boring machines will start burrowing under south London in March.
The extension will link the Charing Cross branch of the northern line with two new stations at Battersea and Nine Elms via 3.2km of underground tunnels.
The machines will excavate 300,000 tonnes of earth each which will be carted off to Essex farmland by barge rather than lorry, to reduce congestion and pollution.
The extension is expected to create 25,000 new jobs as well as 20,000 new homes in London.
The Mayor of London Sadiq Khan said: “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.”