Supporting the Forth

Strainstall, part of James Fisher and Sons plc, provided a rapid response to a sudden transport infrastructure closure by installing its state-of-the-art structural monitoring system, BridgeWatch, onto the Forth Road Bridge in record time.

The Bridge was closed to all traffic at midnight on 3 December 2015 after a crack was discovered in a truss under the carriageway, resulting in long delays as the holiday season approached.

Strainstall immediately mobilised a team of engineers, who had been working close by on the Queensferry Crossing. Together with additional personnel, the team worked around the clock to provide specialist expertise and deploy the BridgeWatch structural health monitoring system – a first for the Forth Road Bridge. By installing a number of sensors in record time, including strain, temperature and tilt, the system delivered monitoring and engineering information to support bridge operator Amey’s planned testing schedule and help ensure the bridge was reopened without delay.

Testing was completed on Saturday over five hours, with the BridgeWatch system providing real-time information on the effects of wind and traffic loading on the integrity of the structure. This data, provided to the bridge’s control room, supported the decision to open the bridge almost two weeks earlier than officials had originally stated.

As the original sensors continue to provide monitoring data, additional sensors will be installed during a second phase to monitor other critical points of the bridge for on-going monitoring and asset management support.