London Overground train capacity to increase
Transport for London is increasing the capacity of the London Overground by 25 per cent in response to increased demand for the service.
Mayor Boris Johnson said five car trains would be introduced due to the success of the line which was completed at the end of 2012 with the link from Surrey Quays to Clapham Junction.
As well as the delivery of 57 new carriages the £320 million improvement programme will also see longer platforms.
Mayor Johnson said: "Passenger numbers on our London Overground services have been going through the roof, but this important programme of investment will enable us to provide the extra carriages required for Londoners to take advantage of what has become the most popular suburban railway in the country."
The service was launched in 2007. The East London Line then became part of the network in 2010 and the Orbital was completed in December.
By the end of last year 120 million passengers had been carried.
The increased capacity also responds to a predicted 810,000 new residents moving into London by 2021.
TfL is in negotiations on when delivery of the new carriages will take place but infrastructure improvements are hoped to start as early as next month.
Each of the new carriage will carry 150 passengers.