Small enough for four people yet vital for millions, a mini rail inspection vehicle was recently spotted running side by side with a train on a railway line in northwest China's Shaanxi Province. The scene uploaded by a netizen quickly went viral online, proving that safety importance isn't measured by size.
The vehicle, officially named the "dual-rail ultrasonic flaw detection vehicle," serves as the exclusive ride for railway inspection crews. "This is actually called a dual-rail ultrasonic flaw detection vehicle. We usually call it the dual-rail flaw detector. It's an intelligent set of detection equipment specifically designed to conduct smart examination on railway tracks," said Liu Huan, the inspection team leader.
While steel rails may appear intact on the surface, years of train traffic can cause microscopic internal damage invisible to the naked eye.
The use of such a dual-rail flaw detector can solve this detection challenge through its sophisticated ultrasonic system. Mounted underneath the vehicle, specialized probes will emit high-frequency sound waves into the rails as the vehicle moves. These signals create real-time waveform images on operators' screens, allowing the four-person crew to "see" inside the steel and pinpoint even the smallest structural flaws that could develop into safety hazards.
The dual-rail flaw detector usually operates during designated "maintenance windows" when tracks are closed for repair work under unified station command, ensuring both operational safety and uninterrupted train service.
Once deployed, the dual-rail flaw detector goes to work - just one trip down the track tells it exactly where every flaw lies. This smart little machine doesn't just cruise at steady speeds, it can also reverse with equal ease when needed.
"The dual-rail flaw detector has nine detection channels on each side, allowing simultaneous comprehensive scanning of both rails. Its battery lasts four hours, enabling inspection of 60 kilometers of track in one go, about four to five times more efficient than manual inspection," Liu said.
Despite its sophisticated technology, the dual-rail flaw detector is surprisingly portable thanks to its modular construction. Crews can easily transport and reassemble its components - from batteries and frame to seats, display screen, wheels and specialized probes - at any inspection site.
"Although small in size, the dual-rail flaw detector is highly capable. Since the summer travel rush began, we've inspected over 800 kilometers of track and found more than ten hidden equipment hazards," Liu said.
Mini rail inspector delivers big safety during peak travel season
