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. It might sound like the obsession of a devout trainspotter but Ravitharan and the Institute of Railway Technology at Monash University, of which he is a director, have become critical cogs helping some of the world’s most impressive public transport networks and supply chains function. It’s why when Dubai’s first metro line started shaking, its operators called Ravitharan.