Crews lace lattice tower sections on the ground. The new galvanized steel structures replaced Cor-Ten structures built in the 1960s.

Dominion Takes Historic Project by Storm

Nov. 24, 2015
Dominion Virginia Power undertakes a crucial rebuild to strengthen its electric grid.

Four years ago, Dominion Virginia Power embarked on the single-largest transmission project in its 100-year history. Important to the regional electric grid, the innovative project focused on rebuilding a 96.4-mile (155-km) line that crosses three states.

Dominion built North America’s first 500-kV electric transmission loop in the 1960s. The 500-kV Mount Storm-Doubs (MSD) line is the major east-west segment along the northern corridor of that 350-mile (560-km) system, spanning six counties from Grant County, West Virginia, east to the border of northern Virginia, then crossing 3 miles (4.8 km) into Maryland, in FirstEnergy’s service territory. The rest of the loop travels south toward Richmond, Virginia, west toward West Virginia and north toward the Mount Storm power station, Dominion’s largest coal-fired power station.

Years of Wear and Tear

After three decades of service, the MSD line began showing major operational issues in the late 1990s. Inherent corrosion and deterioration required continuous maintenance and repairs. Although Dominion was aggressively addressing these aging-asset issues, the deterioration had become so extensive the existing steel towers had to be replaced.

The porcelain insulators and associated hardware were approaching the end of their useful lives. Additionally, the tower grillage foundations were experiencing significant subsurface corrosion even though they were coated initially. Industry studies show conductor splices begin to fail at 40 years. Before being rebuilt, the MSD line required more than 200 conductor splices.

Dominion hired an independent consultant to investigate the condition of the line. The assessment confirmed the critical need to replace the line as soon as it was feasible.

The Mount Storm-Doubs Rebuild Project crosses four counties in West Virginia. The western end of the project (pictured) is near Ned Power Wind Farm in Grant County. Photos by Cameron Davidson.

Improving Reliability

In July and August 2010, Dominion submitted a request to PJM to obtain the necessary outages to rebuild the line. PJM, the regional transmission organization that serves a large portion of the eastern United States, confirmed the need for the rebuild in December of that year, approving the project as part of its 15-year regional transmission expansion plan.

PJM’s operations group confirmed there would be a unique window of opportunity for outages to the MSD line once the new 500-kV Trans-Allegheny Interstate Line (TrAIL) was placed into service in June 2011. TrAIL provided an alternative route for the transfer of bulk power into the large eastern load center around Washington, D.C., and lighter loads during off-peak periods. Meadow Brook-Loudoun was Dominion’s portion of the TrAIL project, which runs from southwest Pennsylvania through West Virginia to northern Virginia.

Further analysis resulted in PJM encouraging Dominion and FirstEnergy to use their best efforts to complete the MSD rebuild by 2015, citing the potential for overloads on the line by summer 2015.

To accomplish this goal, Dominion used the same extensive preplanning, focused timeline management and tested construction techniques that were successful in building the 500-kV Meadow Brook-Loudoun project.

In 2011, Dominion announced plans to rebuild its portion of the MSD line using new, slightly higher 500-kV galvanized-steel lattice towers located entirely in the existing right-of-way. Dominion also proposed replacing the existing conductors with triple-bundled 1351 aluminum conductor steel-reinforced (ACSR) cables for the entire length of the project.

By rebuilding the MSD line with modern facilities, and in accordance with good utility engineering practices as well as National Electrical Safety Code guidelines, Dominion increased the capacity of the line by approximately 66%, from 2,598 MVA to 4,325 MVA.

As part of its regulatory application process, Dominion completed an evaluation of the potential environmental, cultural and historical impacts of the project. Dominion worked with local, state and federal agencies to complete these evaluations and mitigate impacts. Dominion also held open house public meetings in each of the six counties the line crosses. Since no new right-of-way was needed, the MSD line was widely supported in local communities and at the state regulatory level.

Ultimately, this rebuild had considerably less impact for stakeholders and the environment than previously proposed greenfield projects, or projects requiring new right-of-way, in the region. The public would benefit as a result of the reliability improvements in northern Virginia and across the expanded region over the long term — likely postponing the need for more disruptive greenfield projects in the area.

The Public Service Commission of West Virginia and the Virginia State Corporation Commission approved the project in December 2010 and September 2011, respectively. FirstEnergy also worked with the Maryland Public Service Commission to secure approvals for the 3-mile segment crossing into that state.

Dominion’s portion of the Mount Storm-Doubs line is 96.4 miles long. The scenic right-of-way in West Virginia covers more than 65 miles.

A Fresh Approach

A project of this scale required an extraordinary amount of coordination between Dominion employees, contractors and customers in Virginia, West Virginia and Maryland. Dominion hired electrical contractor L.E. Myers Co. to make it a reality.

Previously, during the 2009-2011 construction of the Meadow Brook-Loudoun project, creative approaches to staging material along the right-of-way corridor and scheduling multiple concurrent crews significantly improved the construction process. These construction tactics where refined and replicated during the MSD rebuild.

Construction activities were divided into six categories: road building, structure foundations, material staging, tower assembly, tower erection and conductor installation. Each category had separate crews focused specifically on their own function.

This greatly improved speed and efficiency by enabling simultaneous work to occur at multiple locations along the 96.4-mile project. Construction was broken into four segments, or phases, starting from west to east, providing time to acquire necessary regulatory permits in Virginia while working on the rebuild in West Virginia, where Dominion already had permission to proceed.

Two key attributes made this sequencing possible. Firstly, Dominion’s own in-house engineers designed the line, so when issues arose in the field, line crews had immediate, close coordination with engineering to address matters quickly. Secondly, the foundation crews used low-mast drilling rigs to work underneath the existing energized line. This enabled work to continue on nearly 99% of the new line even during non-outage months.

Much of the terrain crossed by the Mount Storm-Doubs Rebuild Project is rugged and mountainous, such as this section in West Virginia.

Keys to Efficiency

The performance of the Meadow Brook-Loudoun line during the 2011-2012 winter gave PJM and Dominion confidence to revise their planned outage schedules from multiple three-month outages to three nine-month outages. This allowed construction work to continue through the next winter outages of 2012-2013, 2013-2014 and 2014-2015, thus greatly contributing to overall construction efficiency. As a result, Dominion worked closely with L.E. Meyers Co. to develop an aggressive construction schedule to match this window of opportunity.

The rugged, mountainous terrain on the western portion of the MSD line created significant right-of-way access challenges. Passage between towers using the right-of-way was impossible in some areas, requiring more than 100 access roads to be built to reach the 458 towers. By assigning one contractor to focus specifically on road construction, the process had few complications and went much faster than originally planned.

An early decision to use implosive splicing also was a pivotal factor in the success of this project. The method of splicing conductors involves trained technicians using a sleeve with a small engineered implosive charge wrapped around a specifically designed metallic sleeve. The charge created an implosive compression, seamlessly joining the two conductor ends and producing a smoother, stronger and more electrically efficient connection. Construction time was greatly reduced for the 109 splices because the splicing work was able to continue during nearly all weather conditions.

A carefully planned process for installing conductors also contributed to construction efficiency. The line contractor was able to reduce the number of pulling equipment setups by using the old conductor to pull in the lead lines for the installation of the new triple-bundled 1351 ACSR. Working closely with engineering design, Dominion and the contractor predetermined the pull lengths and specifically designated the pulling equipment locations to maximize the duration of wire removal and installation at each pulling site.

Ultimately, the combination of outage extensions coupled with construction and material efficiencies allowed Dominion to complete the project significantly ahead of schedule.

Safety, the No. 1 Priority

Thanks to a well-thought-out project plan, coordination with key partners and employment of lessons learned from the Meadow Brook-Loudoun project, the MSD line was energized on June 3, 2014 — one year ahead of schedule. Dominion achieved this milestone along with industry-leading results related to safety.

“Safety is our No. 1 priority” is more than just a catchphrase at Dominion, it is actually part of the culture — a core value instilled in employees and contractors across the enterprise. Over the three-year project construction period, crews safely logged more than 678,000 man-hours, not including subcontractor hours.

The MSD project reflects the hard work of employees and contractors, an unwavering focus on safety and a commitment to excellence. By taking proactive steps, Dominion was able to replace aging equipment before it failed, ensuring greater reliability for customers and the regional system. 

Wade Briggs ([email protected]) served as the project manager for Dominion Virginia Power’s Mount Storm-Doubs project. He was responsible for oversight and execution of the multi-year project.

Stephenie Harrington ([email protected]) is a communications manager in Dominion Virginia Power’s electric transmission communications group. She was responsible for all aspects of the communications work stream, from project inception through completion.) is a communications manager in Dominion Virginia Power’s electric transmission communications group. She was responsible for all aspects of the communications work stream, from project inception through completion.

Sidebar: Award-Winning Success

The success of the Mount Storm-Doubs project was recognized in 2015 by the Southeastern Electric Exchange, a nonprofit organization of investor-owned utilities, which presented Dominion Virginia Power with the Electric Transmission Industry Excellence Award for its work on the rebuild.

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