NFR deploys underwater robotic drones to inspect 34 Railway bridges
Alipurduar: The Northeast Frontier Railway (NFR) has introduced advanced underwater robotic drones to carry out physical inspections of 34 Railway bridges that remain submerged throughout the year. The cutting-edge remotely operated technology is already being used to examine the underwater structures of several critical bridges, including the iconic Saraighat Bridge over the Brahmaputra and 18 major bridges under the Alipurduar Division.
The NFR’s Railway network spans nearly 4,200 km and includes numerous bridges over major rivers, many of which are filled with deep water year-round. While the Railway Engineering department routinely conducts structural examinations to ensure the safety of passengers, assessing the condition of pillars submerged in rivers such as the Brahmaputra, Teesta, Jaldhaka and Torsa had long been a challenge. The inability to physically evaluate underwater portions of these bridges raised concerns over the health of their concrete pillars.
To address this gap, the NFR has adopted state-of-the-art robotic inspection technology. This year, all 34 identified bridges underwent detailed examinations using an underwater drone equipped with lidar scanning, thermal imaging, ground-penetrating radar, and ultrasonic pulse velocity systems. According to officials, no structural defects have been detected so far in the underwater components of these bridges.
Devendra Singh, Divisional Railway Manager of the Alipurduar Division, said: “Several NFR bridges stand over major rivers, and their condition is monitored throughout the year to ensure the safety of the Railway system and its passengers. But external inspections alone cannot fully assess pillars submerged underwater.
With this robotic system, we can now obtain detailed underwater photographs, radar readings, and ultrasonic pulse velocity data for highly accurate structural evaluations. This year, 34 bridges are under inspection, including 18 in the Alipurduar Division.”
