Even after seven unbroken days on a train from Moscow, nothing can prepare you for the Chinese border. As you pull into the platform, which is lit up in neon colours, a Chinese-tinged version of the Vienna Waltz comes blaring over the Tannoy. Trying to work out the cultural relevance of this is a hopeless task, as the tune soon changes – moving through the works of Richard Clayderman before finishing as you draw away with a stirring rendition of Beethoven’s Fifth. As the music fades, the train rolls into a vast shed manned with soldiers and workers in hard hats. Each carriage is then separated and raised on hydraulics, the wheels removed and new narrower ones rolled into place to match the Chinese gauges – the whole process lasting almost two hours. All while the passengers are still on board.