Innovative Hybrid Route
The onshore transmission route selected by the State Corporation Commission is a hybrid route, where the infrastructure is underground for approximately four miles and overhead for approximately 14 miles. To minimize potential impacts and avoid certain environmental areas, we used a variety of construction methods to install onshore infrastructure.
Underground conduit avoided the sensitive beach area by using a trenchless underground installation method, called Direct Pipe, which simultaneously drilled and pushed pipe deep under the beach to a punch-out location approximately 1,400 to 1,800 feet offshore. To bypass Lake Christine and Lake Rudee, we used another trenchless underground installation method called Horizontal Directional Drilling. For the rest of the underground onshore route, we used duct bank construction methods to place conduit and install cable between manholes.
Overhead cables were installed on parallel transmission poles to transmit the power over the miles between Harpers Switching Station and Fentress Substation. Poles were designed to minimize ground-level disturbance, including to nearby residential communities. A helicopter helped install the new lines safely and efficiently.