L.E. Myers Conquers Rugged Terrain to Rebuild 500kV Transmission Line Nov 12, 2024

Large projects team completes 18-mile wreck and rebuild through mountains and cliffsides of George Washington National Forest

Mountains are a beautiful place for hiking and camping, but they present significant complications for the construction of electric transmission lines. In these conditions, success requires superior planning, coordination and execution.

Those difficulties were in abundance on the Mt. Storm to Valley Phase 3 project which The L.E. Myers Company (L.E. Myers) successfully constructed for Dominion Energy. Equipment had to be brought up cliffsides, wire pulled across valleys stretching a mile wide, and work had to be performed on saddle areas with drops on either side.

"This has probably been one of the most unique and challenging projects of my entire lineworking career, and I started back in 1984," said Senior Operations Manager Michael Comisford.

Comisford led the L.E. Myers large projects team tasked with dismantling existing structures and rebuilding 18 miles of 500kV transmission from the edge of Virginia's Shenandoah Valley through the George Washington National Forest. Originally constructed in the 1960s, the line is part of the first 500kV loop ever built in North America.

Dominion Energy Line Engineer Matthew Vinson called the Mt. Storm to Valley rebuild, "a monumental feat of engineering, permitting, road building, and line construction," and added that Phase 3 was the "most challenging" portion of the mountainous transmission line.

The rugged terrain posed access challenges, imposed size constraints on work areas, and came with many environmental requirements and time of year restrictions. Every transmission structure needed its own plan because of the unique challenges of each tower location.

It was Estimator Trainee Summer Price's first ever job site to work on.

"It was pretty eye-opening to jump into a large-scale project," Price added. "It was really cool to see the problem solving and things that had to go into that."

With careful planning and scheduling, the team successfully completed the full scope of work which included replacing 71 FLT series towers with 5C structures, wire pulls between 1,000 and 4,000 feet long and increasing the line capacity.

Increasing the line capacity was a priority for the customer due to their service territory's ever-growing power demands.

"We have some very skilled craft labor that made this possible, as well as a great deal of planning to make sure we had all the equipment needed, all the techniques needed and communication was on point for getting everyone on the same page day to day, week to week, and month to month as the project unfolded," Project Manager Bradley Saxman said.

Complex Access, Environmental, and Site Constraints Prove No Match for L.E. Myers Team

L.E. Myers, an MYR Group subsidiary, was selected for the project because of its extensive history delivering quality work to the customer, and a proven ability to mitigate cost and provide holistic solutions. They provided a constructability analysis for the entire Mt. Storm to Valley line in 2017, and constructed Phase 2 between 2018 and 2020.

Success was a true team effort, made possible through collaboration between the utility, L.E. Myers and other trade partners. Dominion Energy's extensive planning with the National Forest Service, designing engineered roads, continually adjusting project limits, submitting variances and removing construction obstacles contributed to safer and more efficient access and work pad locations.

"Successful completion of this project was only possible by the strong partnership between Dominion Energy, the prime contractor L. E. Myers, and other subcontractors," Vinson said.

Dominion's engineering group solicited input from project partners that helped facilitate effective solutions to unique challenges and produced positive results. Working closely with the utility's entire team from project management, forestry, permitting, SWPPP management, technical consultants and with subcontractors on this project was essential.

This section of the Mt. Storm to Valley line traverses some of the most geologically challenging parts of the customer's territory, including parts of the George Washington National Forest which runs along the border between Virginia and West Virginia.

More than 60 miles of access roads were constructed just to reach all the structures. This meant traveling between the show up yard and a structure or between two structures could vary from 20 minutes to 2 hours. Sometimes moving equipment from one site to another at the appropriate safe speed took multiple hours.

Working with the utility ahead of time in the pre-development stage to come up with a constructability plan helped provide L.E. Myers with a familiarity of the area including the terrain, access and public roads and yards where they could store materials.

L.E. Myers also had to comply with time of year restrictions (TOYs) and limits of disturbance (LODs) set by the National Forest Service, and Virginia and West Virginia environmental agencies to protect species including salamander and bats. All of these impacted the project's schedule and required excellent planning.

A TOY protecting the Cow Knob salamander required several months of no ground disturbance and the salamander's active areas included a section of the line which needed multiple foundations drilled and structures set. To comply, L.E. Myers scheduled the foundations to be completed by a subcontractor further ahead of setting poles than they typically would to complete them within the window of time where ground disturbance was allowed.

The LODs also limited the size of the work areas L.E. Myers could use within the national forest. Compliance required extensive pre-planning with MYR Group's fleet department to develop equipment plans for some of the large, specialized vehicles (such as cranes) needed for the construction on constrained sites.

Typically, a site has sufficient room to lay out all the materials and steel in pick sections before setting the structure. This saves times and money but was not possible on some of the mountain tops and cliff areas of this transmission line. Where they could, the project team got permission to set structures on cribbing outside the LOD. Where that option wasn't available, the crews assembled the towers one piece at a time.

"We limited our impact in the area and capitalized on the efficiency of removing one and setting one at the same time," Comisford explained.

The transmission construction work was completed in late 2023, while access rehabilitation and cleanup will continue into early 2025.

Project Details: Mount Storm to Valley Phase 3

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