The Delaware River and Bay Authority (DRBA) has used an unmanned aerial system (UAS) to perform an inspection of the Delaware Memorial Bridge Twin Span.

The collaboration of Northeast Philadelphia Airport-based Keystone Aerial Surveys and the professional services firm WSP / Parsons Brinckerhoff has deployed Inspire Pro 1 and Maverik X8 drones to inspect the bridge.

The inspection services have been conducted on the New Jersey side of the bridge complexas a trial and to test the possibility of using the technology to inspect inaccessible areas of the bridge.

"Drones have the potential for making bridge inspection operations significantly safer and more cost efficient."

The UAS recorded video and captured still pictures externally of a concrete pier, within a concrete anchorage, as well as of the steel cable and superstructure of the bridge.

DRBA project engineer Shekhar Scindia said: "The Delaware Memorial Bridge Twin Span is subjected to a rigorous inspection programme every year.

"Drones have the potential for making bridge inspection operations significantly safer and more cost efficient."

The DRBA will be responsible for evaluating the relative quality of the information collected and the operational conditions, compared to existing methods.

Keystone Aerial Surveys executive vice president David Day said: "We are pleased to be able to work with the DRBA on this project.

"We feel confident that our technology can be used to improve and enhance their regular bridge inspection processes."

The UAS technology is expected to perform these inspections with improved quality, in less time and at reduced cost, as well as with significantly less lane closure requirements.

New Jersey’s Cape May County Airport, operated by the DRBA, has also performed drone research campaigns.