30-Mile 138kv New Build/69kV Transmission Line Rebuild — Virginia & Maryland


Riggs Distler rebuilt 30.9 miles of 138/69kV transmission line over five different outage windows in 2017–18 to deliver improved electric infrastructure to the customers of our host utility. The project involved:

  • Replacing 451 wood poles with steel monopoles on foundations or vibratory caissons
  • Upgrading the transmission line from one to two circuits
  • Installing six new conductors
  • Installing two new OPGW lines
  • Installing, maintaining and removing erosion and sediment controls
  • Managing civil contractors installing 451 foundations

Challenges Overcome

Work began after one of the rainiest seasons on record, and many sections of the project area were inundated with water. Our environmental matting team laid the mats necessary to create a stable and safe working environment, and ended up using more matting than anticipated to secure flooded areas. In areas where matting was not possible, Riggs Distler coordinated helicopter long lining to raise the new transmission wire. Despite the difficult working conditions and an accelerated work schedule, our team carefully managed environmental compliance and completed all work within tight outage phases to deliver the project on schedule and on budget.

Results Delivered

Ultimately, our work delivered redundancy in the power supply and a more capable and reliable electric grid for the customers of our host utility without noticeably interrupting their service. Riggs Distler worked safely and efficiently to meet every project deadline and improve power services in these areas of Virginia and Maryland.