Detection of bridge impact
Automated monitoring systems accelerate the response evaluations, help quantify the damage and enable identification of offending drivers for prosecution and recovery of costs
Bridge impact from over-height road vehicles is a persistent problem for bridges with low headroom across the London Underground network. Initiatives to warn drivers have reduced the frequency, but not eliminated the occurrences. Transport for London have chosen to take a combined approach of increasing driver awareness, use of collision protection beams and capturing evidence for prosecution of offending drivers.
London Underground installed three of JF Strainstall's BridgeStrike systems on bridges which were prone to impact and further expanded 18 months later, adding a further eight systems to other sites.
BridgeStrike constantly monitors each bridge for sudden movements, detecting the shock. By learning the normal behaviour, the differences between passing trains and actual impact can be distinguished. When a potential strike is identified by the algorithms, recordings of accelerometer measurements at critical positions and video evidence covering a period before and after the impact are captured.
Notification is sent automatically to the bridge manager(s) and a report is presented including images, assisting the speed of response to inspect and assess the bridge damage. The internet accessible platform, where all BridgeStrike monitored sites are visible along with their current status and history of previous impacts. The platform is accessible from any computer or internet connected device (mobile phone/tablet).
The data recorded has proven successful for the prosecution of drivers and continues to improve the awareness for high vehicle drivers and their employers.
“Throughout the installation of all systems on all assets, JF Strainstall have shown a high standard of compliance in their safety documentation and site teams.” Paul Wilkinson, Senior Construction Supervisor TfL
The use of BridgeStrike systems has brought cost benefit to the management of these bridges. Response has become easier and quicker. Identification of offending vehicles means that many of the costs associated with impacts (closure, examination and remedial works) can now be recovered from the offender.