The 3km Northern Line extension from Kennington to Nine Elms and Battersea Power Station opened to passengers on Monday 20 September.
NLE is the first major addition to the tube network since the Jubilee Line extension at the turn of the millennium. The first train left Battersea Power Station at 05.28, with an initial service of six trains per hour at peak periods and five trains per hour off-peak over the branch. Both frequencies will double by mid-2022.
Transport for London says the £1.1 billion cost of the extension represents a £160 million saving compared to the spending authority for the project. This was increased to £1.26 billion in 2016; additional expenditure was required due to a redesign of the Battersea Power Station terminus following a change to plans for the oversite development above the station.