THE first of a fleet of air conditioned trains which will run through Harrow set off on its maiden journey this morning.

Mayor of London Boris Johnson launched the first of 54 new trains at 8.30am at Willesden Junction, heralding the trains for having air conditioning, more space for passengers, and improved CCTV.

The first 24 trains in the new fleet will run on the north London, west London and Watford to Euston Overground lines, stopping at stations through Harrow and Wembley.

Mr Johnson, boarding the train with London's Transport Commissioner Peter Hendy, said: “For far too long passengers on our Overground lines have suffered from crumbling, unreliable trains that were just not up to muster.

“Every element on these brand spanking new trains has been crafted to meet the capital's needs and the standard of design will surprise even the most hardened traveller.”

An innovation in the new fleet is the ability to walk in between carriages, and they will be equipped with high-tech information screens to keep passengers in the loop.

Today's launch is a crucial step towards London's ambitions to have a fit-for-purpose transport network in time for the 2012 Olympic Games.