115kV Transmission Line Rebuild—New Hampshire

May–June 2020

Riggs Distler was contracted to upgrade aging tower infrastructure along an important 115kV electrical transmission line in New Hampshire. In order to modernize the line and ensure safe operation well into the future, multiple wooden tower structures were replaced with directly embedded, weathering steel structures. The existing towers were affected by bird and insect damage, compression breaks, buckling/leaning, and degradation due to rot and decay. Our work included:

  • Replace 7 wooden tangent structures with new weathering steel tangent structures. 
  • Replace 4 wooden running angle structures with new weathering steel running angle structures. Install cassions for all non-ledge set structure replacements 
  • Install new guy anchors will be required. 
  • Extensive environmental matting for access roads, environmental controls, and site support. 

Challenges Overcome

Riggs Distler’s greatest challenge on this project was the terrain. The work sites for each tower were located in remote areas, and our drilling and line crews had to use full-track equipment to access the tower sites and complete the work. Work had to be carefully planned and contingencies built into the daily schedule, as there was no cell phone or wifi service to connect to support staff in our offices. The project had to be completed within strict outage windows specified by the client, and our main focus in the field was keeping up with the project schedule while performing all work safely. 

Results Delivered

Despite the challenges faced, Riggs Distler completed all work on schedule and completed the upgrade of our client’s transmission line infrastructure, ensuring safe operation and reliable electrical service for power users throughout the area. As a result of our performance, the client secured Riggs Distler’s services for four additional projects in New Hampshire, which are currently underway.