In London, Metronet Rail has unveiled the new Tube trains that will run on four of the 12 lines on the London Underground.

Much was made of the operational improvements offered by the upgrade, but to many commuters the most welcome news will be the long awaited introduction of air conditioned carriages to the network. The trains will be introduced on the Metropolitan line by the end of 2009, with phased introduction to the Circle, District and Hammersmith & City by 2013.

Metronet said the new fleet would give a 25% increase in capacity through faster journeys, more frequent trains, more spacious trains plus a seventh carriage on certain lines. Reliability and enhanced comfort for passengers were also listed as positive deliverables.

The trains are the most visible sign of a US$6bn upgrade being carried out to the lines, but other aspects include a new signalling and control system to allow the trains to run faster and closer together, new control centre, upgraded track layouts and power system. Mark Loader, vice president in charge of Metronet’s upgrade said the project: “Is the largest of its type anywhere in the world and is of a similar scale to the Channel Tunnel Rail Link.”