InTrans / Aug 14, 2018

Remote Monitoring of Historic Covered Timber Bridges for the Prevention of Arson and Vandalism

More than 700 historic covered timber bridges remain in the United States. In recent years, a number of these bridges have been targeted by vandals and arsonists. Obviously, prevention of future acts of vandalism and arson is important to retaining the invaluable parts of our engineering heritage.
A research team from Iowa State University, working cooperatively with the United States Department of Agriculture Forest Products Laboratory (FPL), developed a remote security and fire detection monitoring system for covered timber bridges. This system automatically notifies emergency response personnel in the event that a fire is detected or if unauthorized activity occurs. The system was installed on the Cedar Bridge in Madison County, Iowa in 2005.
Three independent detection systems were software-integrated and installed. Fiber optic sensors were installed to monitor ambient temperatures throughout the bridge. An infrared camera, which is able to detect temperatures in an electronic image, was installed near the bridge. The data from these two parts of the monitoring system are used to detect rapid temperature changes due to fire and to also identify unauthorized persons on site. In addition, an industrial flame detector, which monitors radiant emissions within infrared and ultraviolet wavelengths, was mounted within the bridge interior. All of these components were connected using an onsite, wireless computer network with custom developed system integration software.