The project to lengthen trains on London Overground from four carriages to five has finally become a reality with the first lengthened train now in public service.

Work to extend platforms at Canada Water and Surrey Quays has now been completed.

At Rotherhithe the longer trains will not fit into the platforms so the two rear sets of doors in the back carriage will not open at this station.

At Canada Water even the extended platforms are too short so the rear set of doors will remain shut.

Mayor of London, Boris Johnson, said: “With punctual services and an ever growing number of passengers I think it’s fair to say that London Overground has been a fantastic railway success story. Adding an extra carriage to the trains that criss-cross this network will allow more people to take advantage of what is now one of the most reliable and trusted rail services in the UK. As London’s population continues to rise, it is investment in our transport network like this which will help to keep London and its economy on the up.”

TfL’s Managing Director of London Rail, Mike Brown, said: “The ever-increasing popularity of the London Overground network has seen a huge rise in demand. As a result, we are now on course to carry 135m passengers – nearly four times the number we carried when we took over this railway in 2007.

“To enable us to continue and maintain the high levels of safe, reliable and frequent travel that our customers have come to expect, it is vital that we deliver more capacity by lengthening our trains from four to five carriages.

“We have set a standard for highly successful rail services and this is the model we will follow when we take over three-quarters of the rail services out of Liverpool Street station next year.”