Guwahati: The Northeast Frontier Railway (NFR) has begun using underwater robotic technology to carry out detailed structural inspections of key railway bridges, including the iconic Saraighat bridge over the Brahmaputra, officials said on Monday.
The railway has employed advanced Remotely Operated Robotic Vehicles (RORVs) to examine substructures that remain submerged throughout the year.
These inspections help assess the condition of wells, foundations and piers—critical components often inaccessible through conventional methods.
The Saraighat bridge, the country’s first rail-cum-road bridge and a vital transport link for the Northeast, was assessed using a combination of RORV surveys, LiDAR, thermal imaging, Ground Penetrating Radar and Ultrasonic Pulse Velocity tests.
The evaluation covered pier caps, well foundations, scour zones, deck components and stress points on the superstructure.
ALSO READ: Meghalaya: HITO urges Centre to halt proposed Shree Cement plant in East Jaintia Hills
NFR said 18 other major bridges under the Alipurduar division were also inspected using RORV systems, which provided high-resolution visuals of submerged piers, riverbeds and potential structural vulnerabilities.
No major underwater defects were found during the assessments.
In 2024–25, NFR completed underwater inspections of 13 bridges using robotic systems, while 34 more have already been examined in 2025–26.
The railway said the integration of RORV technology with digital tools has significantly improved the accuracy of structural health monitoring and will aid in planning preventive maintenance.
