At 4:30 a.m. last Thursday, PCL Construction workers at the Outer Banks Bonner Bridge construction site moved a steel casing aside for storage and drove it into the ground, as someone might stick a shovel in the dirt when it’s not needed, according to the N.C. Department of Transportation. In doing so, the casing damaged two of the three 115 kV underground transmission cables supplying power to members of Cape Hatteras Electric Cooperative (CHEC) and Tideland Electric Membership Corporation on Hatteras and Ocracoke islands.
With roughly 10,000 meters affected during peak tourism season, the co-ops worked quickly to restore power with permanent and temporary diesel generators as Dare and Hyde County officials ordered nonresidents to evacuate the islands. By midday Saturday, July 29, both co-ops had restored power to full-time residents.
“We’re very appreciative of some of our largest island members agreeing to remain on their own standby generation while we normalized loads on the diesel generators,” said Tideland EMC General Manager and CEO Paul Spruill. He added that local residents took early calls for conservation seriously, and real estate companies went door-to-door, shutting the main breaker off at unoccupied rental homes. “Managing this has really been a community effort.”
After assessing the damage, CHEC and a team of contractors and specialists began two simultaneous projects to restore power from the mainland: repair of the underground cables and construction of a new overhead line.
“I told people, don’t cancel your vacations, because they’re going to work hard,” Governor Roy Cooper said following a Monday visit to the site. “They’re going to work hard to get this thing fixed.”
As of this morning, CHEC has narrowed its estimated remaining timeframe to restoring transmission services to 3-5 days, down from a previous estimate of up to two weeks, and has deemed the overhead option as the safest, quickest way to restore power.
(Right to left): Gov. Cooper speaks at the bridge site, joined by N.C. Secretary of Transportation James H. Trogdon III, CHEC General Manager Susan Flythe, and Dare County Commissioners Danny Couch and Bob Woodard.
Overhead Solution
Yesterday, crews finished setting all of the poles required to build an overhead transmission line, as well as anchored the poles and built structures to accommodate other system components. They began installing the three-phase line last night. A specialist team from CHEC contractor New River Electrical is executing prep work for the highly technical process of connecting the new overhead cables in two places: To the existing underground lines just before the site of the damage and to the existing overhead lines that run the length of Hatteras Island.
These new overhead lines will connect underground cables to existing transmission.
Underground Solution
Repairs to the underground cables have presented challenges, as the trench at the site of the damage is adjacent to the sound and must be constantly cleared of water. New River Electrical has, however, repaired one of the two damaged cables. The second remains difficult to access.
“Despite PCL Construction’s tireless excavation efforts and attempts to dewater the trench at the site of the damage, trench conditions proved to be too challenging for the underground solution to be viable,” CHEC General Manager Susan Flythe said. “PCL Construction was able to reveal all three cables, but water continued to seep into the trench making the environment unsuitable for repairs.”
Electric co-ops across the state have provided moral support and supplies throughout the restoration process. Brunswick Electric and Roanoke Electric have been on site during repairs with crews and supplies.
CHEC and Tideland EMC have kept members constantly updated, using social media as a key means of communication. CHEC’s Facebook following has grown from approximately 3,000 followers before the crisis to 15,000 followers. Posts are being viewed as many as 250,000 times each. A post from yesterday evening has already received more than 2,300 likes and been shared more than 1,000 times.
Tideland EMC’s Facebook page has also provided members with steady updates. In addition, the co-op opened up its outage text messaging service to non-members, with 700 new cell phone enrollments since the transmission outage began.