Real-Time Monitoring Keeps Vital Repairs on Track for the New York City Subway Rockaway Line
92
sensors
installed across the bridge in just 3 days, allowing real-time data collection for structural safety during construction.
0
delays
caused by inspections – enabling uninterrupted subway service for thousands of commuters everyday.
30
minute
data intervals during initial monitoring for precise, real-time alerts for any rotation, deflection, displacement, or deformation of tracks, piers, or the bridge structure.
In 2012, Hurricane Sandy heavily damaged the North Channel Bridge in Jamaica Bay, New York. This part of the Rockaway Line provides an important connection between Queens and the rest of New York City. The bridge took a direct hit from the storm, resulting in the timber fender system needing to be repaired fast. But while significant work was needed, it was not feasible to halt the line’s operation.
The Challenge
The repair project began in 2022. The nearest land points from the North Channel Bridge were almost 2,000 feet away. This significant distance created challenges for traditional survey technologies, which typically require accessible backsights for accurate deformation monitoring. With trains passing over the bridge throughout the day, the need to work over water and frequent marine traffic causing the timber structure to move erratically, working safely was challenging. Being able to effectively monitor vibrations, structural stability, and track alignment was critical.
The Solution
Given the challenging track configuration, we advocated for a more innovative approach. We installed an advanced wireless monitoring system with 92 sensors placed along the track. This system tracked deformations, vibrations, and tilt in real time, providing updates every 30 minutes. As a result, potential risks were addressed early and construction proceeded with no disruptions to subway operations. This monitoring solution is now a standard requirement for the Metropolitan Transportation Authority (MTA) in similar projects.
Why Certerra?
Our expertise in monitoring and safety systems for complex infrastructure enabled us to think outside the box and propose the right solution. Our proactive and collaborative approach allowed us to install all 92 sensors in under three days – helping to keep these vital repairs on schedule. This project shows our team’s expertise, innovation, and commitment to excellence – earning the client’s trust and setting a new benchmark for future infrastructure projects.