Midnight Express: 'Night warriors' behind China's bullet trains

It wouldn't be possible for China to operate some of the world's fastest trains, traveling at the speed of up to 350 kilometers per hour, without maintenance teams working their fastest through the night to keep the trains going uninterrupted.Since these trains operate as per tight schedules, maintenance crews have only about four and a half hours, sometimes even less, to accomplish their task. It's the job they have to do night after night on time and without fail.