Manhattan Bridge Monitoring

The Manhattan Bridge is a suspension bridge that crosses the East River in New York City, connecting Lower Manhattan (at Canal Street) with Brooklyn (at Flatbush Avenue Extension). It was the last of the three suspension bridges built across the lower East River, following the Brooklyn and the Williamsburg bridges. The bridge was opened to traffic on December 31, 1909. The total length of the bridge is 2,089 meters [6,855 ft], the length of suspension cables is 983 m (3224 ft) and the main span has a length of 448 m ((1,470 ft).

Aim of monitoring:

In the framework of a program on suspension bridge corrosion monitoring, it is desired to acquire continuous data on the strain, deformation and temperatures of the main cable and anchorage of the bridge. The data generated by the monitoring system will be used to provide baseline data and to verify the the ability to detect wire breakage through deformation. SOFO sensors of 6 meters have been installed on one main cable straps. Two other Bragg grating strain sensors have been installed at the anchors on individual strands. The purpose of these sensors is to measure strain on main cable and one hanger as a function of: temperature variations, time of day (sunshine), time of year (seasons) and traffic conditions (day / night).