Protecting the bridges of Madison County

IowaStateUniversity engineers are developing round-the-clock monitoring technology to help protect the bridges of MadisonCounty.

That same technology could be adapted to any bridge where security is an issue, said Terry Wipf, the director of IowaState’s BridgeEngineeringCenter.

MadisonCounty’s historic covered bridges have been arson targets in recent years. A September 2002 fire destroyed the 1883 CedarBridge. A year later the 1884 HogbackBridge was damaged by an arson attack.

Engineers from the BridgeEngineeringCenter are now testing a monitoring system that will cover one of the bridges with three layers of remote monitoring equipment.

Brent Phares, the associate director of the BridgeEngineeringCenter, said the equipment includes flame detection devices, which detect infrared light, ultraviolet light and the flicker rate as the light frequencies change. Phares said flames emit a light signature the devices will recognise.

Other monitoring equipment includes infrared cameras and fibre-optic strain gauges that will be attached to the bridge and will measure changes in temperature.

Data from the monitoring equipment will be collected and processed by a computer at the bridge, Phares said. If the equipment detects something suspicious, emergency crews will be notified. Dispatchers will also have access to video images from the monitoring equipment so they can determine whether there’s an emergency.

The equipment is expected to be installed on one of the covered bridges by September. Engineers and police officials will then stage mock arson and vandalism incidents to test the system’s capabilities.