Photo: Outer Banks Task Force

What's the Deal with the Bridge?
Bonner Bridge undergoing inspections

by Rick Kinnaird

There’s lots of talk and speculation about the Bonner Bridge at Oregon Inlet. First there was a big article in the Island Breeze. Then there were big backups at the bridge. Rick Neuman, one of our neighbors in Bethesda, MD, reported long delays at the bridge because of inspections and repairs on a recent trip to Hatteras Island. Apparently, the bridge is sometimes reduced to one lane of traffic and trucks, big dump trucks, have been going across it very slowly. Our fishing friends, Dolly and TJ, say they've heard rumors that the bridge is going to close, but say they don't believe it.

Other rumors have been swirling around. We've heard that heavy trucks will no longer be allowed to cross the bridge. We've heard that the bridge will probably wash away in the next hurricane. We've heard that ferries will be brought in. With all of this talk, rumor and speculation, we decided to call the state's Department of Transportation to get the real story.

I spoke with Don Idol in the Bridge Maintenance Unit at NC’s DOT. Don says there are three things going on with the bridge. One is a regularly scheduled inspection of the bridge that happens every two years. The other is an assessment with recommendation as to what to do to make sure the bridge is functional until 2015. And the third is an ongoing contract to repair some of the concrete girders and a few areas on the bottom of the slab.

The field work for the assessment should be completed in early June. Part of this assessment is to check the concrete, especially underwater, looking for chlorides and other signs of deterioration. They will first inspect the high parts of the bridge and then they’ll look at the rest. There is concern that some of the shotcrete added in 1986 is deteriorating and they are trying to determine its condition. Shotcrete is pneumatically applied wet concrete; gunite is dry concrete blown out of a nozzle with water applied as it comes out. (Not that you asked, but you can start a fight among concrete applicators if you claim one is better than the other.)

In DOT's inspection of the bridge, they found one of the girders exposed and much of the prestressing broken (that apparently means some of the wire in the concrete). They naturally wondered how much load that part of the bridge could take and hired the same firm that stress tested the Green River Bridge a few years ago.

Here’s what they do. They epoxy little wires in place that cover the span they are interested in. Then they apply a “known load” to the section and check the micro-voltages on the epoxied wires. The known load in this case was a fully loaded dump truck, driving over the area several times very slowly. Ah ha! Now we know where the slow moving truck rumor came from.

I asked Don why the bridge had been reduced to one lane? Both the repair contractor and the inspection contractor were reducing portions of the bridge to one lane in order to do their work. The inspection contractor completed all lane closings on May 12. The repair contractor stopped daytime lane closings on May 25 so the bridge would be in full service for Memorial Day Weekend. The contractors repairing the bridge may choose to work at night from 10 pm until 6 am Monday through Thursday throughout the summer and could reduce traffic to one lane during those times or they may opt to wait until after Labor Day to finish their repair of the bridge. The repair contract is scheduled to be completed by November 2006.

As far as restricting trucks on the bridge – no one in DOT is talking about that as a possibility. Typically, stress tests reveal bridges to be stronger than calculated.

What about the ferries? The bridge inspection folks know of no plans to begin using ferries at Oregon Inlet. Don said the ferry division periodically performs preparedness assessments and one of those could have been happening, but he isn't sure.

And, finally, are they going to do the short span (replace next to current bridge) or long span (replace with 17-mile long bridge that bypasses Pea Island)? Don said everyone is waiting for various State and Federal officials to comment.

So there you have it – the truth!

For more information on the Bonner Bridge Replacement Project, click here to read a document issued by the U.S. Fish & Wildlife Service.