London Overground: Design work for West London Orbital route begins
Plans for a new London Overground link in west London are progressing, London's mayor Sadiq Khan has said.
Engineering consultants who worked on the Elizabeth line have been chosen for the West London Orbital service.
"This engineering design will help determine the cost of delivering the scheme, which is currently unfunded," Transport for London (TfL) said.
It hopes the scheme, which would connect Hounslow with Hendon and West Hampstead, could start next decade.
The design work is being funded by the West London Alliance, a partnership between the boroughs of Barnet, Brent, Ealing, Hammersmith and Fulham, Harrow, Hillingdon and Hounslow.
It will be carried out by international engineering consultancy Mott Macdonald, TfL told BBC London.
The company previously advised on the Elizabeth line's route, structures and rail systems.
Last month the mayor of London was asked to provide an update on the project's progress by Elly Baker, Labour Assembly Member (AM) at City Hall.
In a written answer, he said the modelling and consulting work would "lead to an updated business case for the scheme and confirmation of the stations to be served".
He added that a Network Rail timetable assessment found the "West London Orbital service is expected to be achievable".
If it goes ahead the route would span approximately 11.5 miles (18.5km) across four boroughs and make use of track currently used by freight services in west London, TfL proposals state.
Four new stations would be built along the route, while Old Oak Common is expected to become a new super-hub station, connecting the Overground to High Speed Two (HS2) services and the Elizabeth line.
The plans are not yet approved and a public consultation about the route will be held in the future.
Follow BBC London on Facebook, Twitter and Instagram. Send your story ideas to [email protected]