Transmission Crews Handle Tough Job on Raccoon Mountain

When a routine inspection revealed damage to a 161-kilovolt transmission line on Raccoon Mountain, transmission crews braved rugged terrain, inclement weather and a design challenges to fix it quickly.

MAY 15, 2017—Transmission Power Supply recently completed a “rush” job under difficult working conditions, bad weather and a challenging design dilemma.

A routine inspection revealed damage to a structure on the Raccoon Mountain—Moccasin #3 161-kilovolt transmission line. One leg of a structure failed due to a shifting foundation, which also caused the tension on the conductor to exceed design specifications.

transmission workers

Situated on the side of Raccoon Mountain, the rugged terrain—in combination with several other nearby high-voltage transmission lines—required extra safety precautions as Transmission Construction crews prepared the site, installed a new structure, moved the conductor (six wires) to the new structure, removed the damaged tower and then restored the area.

The work also involved coordination with TVA Natural Resources on a bike trail re-route that the work affected.

“It was a noteworthy accomplishment,” says David Mullin, senior project manager. “I want to recognize a few key individuals, along with the entire project team. Jeremy Pettus [civil engineer] developed an outstanding, flexible design to solve this unusual problem. Joe Melton [environmental scientist] provided the environmental review. Brad Moore [transmission right of way forester] worked quickly to improve access to the construction site and add barriers to keep hikers and bikers at a safe distance from the work areas. Cody Young [transmission field construction supervisor], along with the line construction crew, worked safely, under dangerous conditions and in inclement weather to retire the original double circuit tower and replace it with two, two-pole guyed dead-end structures, plus replaced the conductor and static ground wire from structures 5 to 6.”

powerline structureThe star design of these transmission structures is unique. The lower profile structure was designed for 161-kilovolt lines that had a 500-kilovolt line crossing over them. Only seven were built on the TVA transmission system and with the removal of this one, only six remain. Five are on Raccoon Mountain and one is in northeast Tennessee.

TVA’s transmission system consists of more than 16,200 miles of line and 104,000 structures that are regularly inspected.

About TVA Transmission

As one of the largest transmission systems in North America, TVA’s 16,200 miles of line—enough to span the United States six times over—provide the critical link that connects power from our generating plants through a network of 154 local power providers to 9 million people in the Tennessee Valley across 80,000 square miles in seven states. Learn more about TVA Transmission.