AASHTO Journal, 11 December 2015
The Connecticut Department of Transportation will use an unmanned aerial vehicle, or drone, to “perform limited visual bridge inspection tasks” this month of its mile-long Gold Star Memorial Bridges on Interstate 95.
The announcement said this was part of “CTDOT’s ongoing mission to improve and evaluate its operations and to assess the usefulness and functionality of new technologies.”
Other state DOTs have also begun to explore use of aerial and underwater drones to check infrastructure in areas that are physically difficult for crews to inspect in person. The AASHTO Journal reported in October on such testing by the Minnesota DOT.
The Gold Star Memorial Bridges, CTDOT said,are two distinct structures carrying I-95 northbound and southbound over the Thames River between Groton and New London. “The structures are the longest bridges in the state at roughly one mile each, with the main spans rising approximately 100feet over the Thames River.”
During October, the agency completed a full routine inspection of the Gold Star Memorial Bridges using traditional methods of getting inspectors in close with lifts, by using climbers and ropes, or “snooper-trucks” with baskets that can sit atop the bridge but take inspectors under parts of it.
It will use the UAV on Dec. 15, with Dec. 16 as a backup inspection date in case of inclement weather.
The process will gauge the ability of the UAV to provide access to the structure, and to photograph areas of the northbound bridge that are typically difficult to reach by snooper-trucks or ropes and climbers.
“This is an important step for our agency: The testing of a new technology with the potential to improve results, efficiencies and safety for the public,” said Commissioner James Redeker.
“The willingness to examine new technologies – to innovate and to keep an open mind – is critical if we are to find better ways of doing business, and I applaud the Department’s Bridge Safety Division for initiating this test.”
One it completes the drone testing, CTDOT will perform an analysis that looks at the advantages and disadvantages and the UAV’s effectiveness in gathering detailed information compared with conventional inspections.
The outcome of that review will help determine the potential for UAV bridge inspection technologies to improve upon or supplement bridge inspection processes on select structures throughout the state.
