Hurricane Michael caused extensive damage to Florida’s power grid network, leveling more than 100 transmission towers in a 34-mile (55-km) right-of-way from Port St. Joe to Callaway. This right-of-way crosses swampy, remote and hard-to-reach areas, making rebuilding the grid even more challenging. This extremely wet, muddy ground prevented Duke Energy repair vehicles from accessing the area for repair efforts. In order to install new towers in the shortest timeframe, helicopters were employed to bring in new steel towers.
Accessing the lines for maintenance would require a stronger roadway to support heavy vehicles in the wettest areas. Duke Energy turned to local materials supplier, R. H. Moore & Associates, for a solution that could get roads operational in short order and perform in the saturated conditions—the GEOWEB® 3D system and Mirafi RS580i geotextile were chosen.
The downed towers were damaged beyond repair and would be replaced by stronger steel poles. Because of the remote location, extremely saturated ground and difficulty in accessing these lines, the towers, weighing 8,000 to 25,000 pounds (3,630 to 11,340 kg), were set by a fleet of Black Hawk helicopters. Crews on the ground installed the towers, which were transported in two to five parts and reassembled onsite.
Between the terrain, scope of damage and demand for supplies following the storm, rebuilding this critical transmission line was a challenge. Transmission towers carry large amounts of power from power plants to the grid and are some of the grid’s largest and sturdiest pieces of equipment. Despite their size, Hurricane Michael was able to destroy them, causing 75,000 outages.
Duke Energy crews worked long hours for more than three weeks to rebuild the grid and restore power.