NFR scans 34 bridges with underwater robots; Saraighat passes structural checks

Guwahati, Dec 1: The Northeast Frontier Railway (NFR) has adopted underwater robotic vehicles for extensive structural inspections of major railway bridges, including the Saraighat Bridge over the Brahmaputra in Guwahati.

It has employed advanced Remotely Operated Robotic Vehicle (RORV) technology for the purpose.

Critical bridges such as the Saraighat bridge and several other important bridges under the Alipurduar Division of NFR have been inspected using the technology.

These bridges have substructures that remain submerged year-round, making underwater inspection essential for assessing the condition of foundations, wells and piers.

The historic Saraighat Bridge, India's first rail-cum-road bridge, spans 1.45 km and connects Pandu and Amingaon.

As one of the most vital rail–road lifelines of the Northeast, it was inspected using a combination of RORV surveys, LiDAR, thermal imaging, Ground Penetrating Radar (GPR) and Ultrasonic Pulse Velocity (UPV) tests.

The assessments covered pier caps, well foundations, underwater scour zones, superstructure stress points and deck components.

Another 18 important bridges were also inspected thoroughly with RORV, capturing high-resolution visuals of submerged piers, riverbeds and potential defects.

Across all these structures, no major underwater defects were detected.

During 2024–25, NFR completed underwater inspection of 13 bridges using RORV, and during 2025–26, 34 additional bridges have already been inspected.

These insights enhance the accuracy of NFR's structural health monitoring and support the timely planning of preventive maintenance.

The application of RORV, coupled with advanced digital tools, marks a significant step forward in scientific bridge assessment, the statement added.

PTI