SCE&G's Largest Underground HV Transmission Project

To better serve its growing number of customers and to provide greater service reliability, South Carolina Gas & Electric proposed a new 115-kV electrical transmission line in 2007 called the Hamlin 115-kV tie line. At the request of the Town of Mount Pleasant, from 2007 to 2009, SCE&G studied the option of placing a larger section of the line underground. In 2009, SCE&G began to investigate additional underground options that would place three existing radially fed substations into a loop system arrangement, embarking SCE&G on the largest underground high-voltage transmission project in company history. Following are images of the installation process. For further detail on the project, see "115-kV Cable Installed Across a Tidal Marsh," featured in the April 2017 issue of T&D World.