Meet the man who keeps the world’s busiest railways running from a shed in Melbourne

Prof Ravi Ravitharan is the director of the Monash Institute of Railway Technology, which has clients including the mega-city of Hong Kong. Photograph: Eugene Hyland/The Guardian

When a train on Hong Kong’s metro is speeding along its route slightly bumpier than usual, Ravi Ravitharan’s phone buzzes in Melbourne – at all hours of the day.

“My phone is next to my bed when I sleep because we will get calls in the middle of the night,” he says.