The new fleet will proceed from the conversion of existing Alstom-built fleets based on the Alstom Coradia platform. It will enable around 8,000 extra peak-time passengers to travel into London's Waterloo station every morning, as eight-car trains will be lengthened to run in 10-car formation on certain routes.
Known as Class 458/5, this new fleet will be delivered through the conversion of two existing Alstom-built fleets, the Class 458s, used by South West trains and Class 460s, formerly used on the Gatwick Express route, serving Gatwick Airport. The modifications will include conversion of cabs, gangways, as well as conversion of baggage areas into passenger saloon areas.
The new vehicles will be brought into service in the spring of 2013, with the final train scheduled for delivery in spring 2014.