Steel casing was being set aside when it cut power to Hatteras

By Rob Morris on July 31, 2017

Workers at the site of the dig where the cut occurred. (Rob Morris)

Susan Flythe of CHEC briefs Bob Woodard, Chairman of the Dare County Board of Commissioners, and Gov. Roy Cooper.

As Gov. Roy Cooper looked over the damage and offered assurances that every effort was being made to restore power, more details emerged Monday on how the only source of electricity to Hatteras and Ocracoke islands was severed in a construction accident last week.

Crews at the south end of the Bonner Bridge over Oregon Inlet were close to finding the last of three underground cables Monday afternoon but were having trouble pumping water out so that final repairs could begin.

One cable was spliced back together overnight after losing a two-foot section. A third first thought to be damaged was later found to be intact.

Cooper said he and his administration have offered the Cape Hatteras Electric Cooperative “all the resources that they need to get power back to these islands as quickly and as safely as possible.”

“Clearly when you’re talking about the economy of the Outer Banks, summertime is a great time for people to make their money and this situation has hurt,” he said. “So every day is important to the economy of this part of our state.”

The cooperative said today that it could be one or two weeks before full power is restored. But the company is trying to beef up its temporary generator system in hopes of allowing a staged return of visitors.

In the meantime, mandatory evacuations remain in place, which is preventing new visitors from reaching their rental houses on the islands. Residents are allowed to stay.

The power went out at 4:30 a.m. Thursday when the company building the replacement for the 50-year-old Bonner Bridge drove a steel casing into the electrical transmission system.

Casings are giant tubes that enclose individual concrete pilings to keep them in position while they are installed in clusters at various angles to support the bridge deck, said Jerry Jennings, District 1 engineer for the North Carolina Department of Transportation. Workers were setting aside the casing for future use by driving it partially into the ground.

The steel casing is the large brown tube on the right. (NCDOT)

Susan Flythe, executive vice president and general manager of CHEC, said it was not long before they realized there was a problem.

“As they drove that casing down into the ground, they heard a pop,” she said.

Power is delivered by three cables because electrical transmission employs a three-phase system to keep the current stable and flowing economically. All three are needed to make it work.

Thousands of people are waiting to hear whether their vacation plans can be salvaged, but no estimate for when power might be sufficient is available yet. In a typical summer week, 50,000 to 60,000 people vacation on the island, according to Dare County Public Relations Director Dorothy Hester.

Ocracoke is running on three portable generators, and there is no word yet about the possibility of producing enough temporary power to allow visitors back in. More than 3,000 people left on ferries after the evacuation for visitors was ordered last week.

But in a statement Sunday, CHEC said it was working “to expand the temporary generation service on Hatteras Island, in order to accommodate a staged re-entry of visitors.”

Two ideas for repairs are in play, the cooperative said. One is to splice the last damaged cable back together.

The second idea is to connect a new power line to the south end of the Bonner Bridge, run it overhead south along the east side of N.C. 12, then across to existing poles on the west side, Flythe said.  By Monday night, seven of the 10 poles needed had gone up.

Now, the existing lines are carried over Oregon Inlet by the bridge, then run underground before emerging onto the power poles south of the inlet. The transmission system will eventually be moved to the new bridge.

“CHEC will actively pursue both of these solutions until it is clear which of these will provide the fastest and safest option for a full repair,” the statement said.

“Depending on which solution turns out to be the most practical, the timeline for a complete repair could vary from one to two weeks.”

A makeshift system of portable generators and a permanent diesel backup system in Buxton is now providing minimal power to Hatteras Island.