London mayor Boris Johnson said: "It's fantastic to think that these sleek new trains will soon be transporting millions of people across our great city and beyond. They're feature packed, eye-catching machines that showcase the best of British design and engineering. They'll add vital capacity to our rail network and will help to ensure our economy continues its onward journey full-steam ahead. The largest construction project in Europe is another tantalising step closer to becoming a brand new working railway for the Capital."