Most transmission line construction projects go from point A to point B, removing the old conductor and materials and installing a new conductor. The New River to Wire Road project that Service Electric Co. (SEC) is constructing for Duke Energy Florida, St. Petersburg, is more intricate.
The project—begun in January 2020 and slated to be complete in April 2022—involves construction of approximately 20 miles of new transmission line, connecting that new line into seven different substations. It also involves rebuilding an existing 2-mile, 115-kilovolt (kV) transmission line, expanding the existing New River Substation by building a new 230kV yard and constructing the new Wire Road Substation. All this is to meet the anticipated population growth in Florida’s Pasco County.
SEC, Leesburg, Fla., has served the electric utility industry since 1945 with more than 1,500 employees and a fleet of some 2,000 pieces of equipment. It is a wholly owned subsidiary of Houston-based Quanta Services, the nation’s largest specialty contractor, which provides end-to-end network solutions to the electric power and gas industries in North America, Canada and Australia.
SEC’s services include construction and maintenance of overhead distribution and transmission lines including 765kV substations, underground distribution systems, fiber optic networks and technical services/commissioning (transformer filling, testing, reclamation, refurbishing, dehydrating). It also offers a wide range of high-voltage and extra-high-voltage energized transmission and substation construction and maintenance services. SEC emergency restoration crews have responded to customers throughout the eastern United States in the aftermath of hurricanes, tornadoes and other natural disasters.
For the New River to Wire Road project, SEC planned to perform mostly deenergized work. However, due to losing clearances that had been set up months in advance, the company shifted to an energized work practice, a specialty type of transmission construction that SEC regularly performs.
The overall project has five segments.
The T1 segment construction involved installation of a new 230kV line between the existing New River Substation and the new Wire Road Substation. Population growth in the area resulted in the potential of the power line being upgraded to handle the expected new load. The project included the installation of 313 steel and concrete foundations.
The T2 segment—from Kathleen to Zephyrhills North (KZN)—-entailed looping of the existing KZN 230kV line into the new Wire Road Substation.
The T3 segment involved looping the existing KZN-2 230kV line into the new Wire Road Substation.
The T4 segment involved rebuilding the existing 69kV lines from Zephyrhills North to the New River Substation, a line that combines three existing segments that were co-located with the new 230kV line.
The T5 segment of the line from New River to Cabbage Hill Substation involved rebuilding the existing 69kV line, an installation that is part of the new 230kV line between the Morgan Road and New River substations.
Challenges included acquiring outages, redirecting the transmission lines using temporary poles, transferring existing wire to new poles, installing new structures and co-locating them on double-circuit structures with energized portions of the existing 115kV line and portions of the existing 69kV transmission line. While setting new structures, SEC workers had to be aware of underground conflicts, such as cables, roots, rocks and telephone or internet lines, so that residents and companies in the area wouldn’t be affected.
Brian Brogan, SEC superintendent, and his team that included general foremen Eric Lester and Chad Brady, identified possible problems and evaluated existing conditions. They collected data that assisted engineering teams and other personnel with the design and construction planning for the project prior to final construction. Local property owners were notified to discuss the process when a new easement or an update to a current easement was required and when it was necessary to clear obstructions or vegetation on their property.
In this project, the load potential was critical due to the need for an upgrade to the brand-new 230kV line. As a result, outages were time sensitive. Portions of T1, T4 and T5 had to be transitioned from “cold work” as initially designed to “hot work” to keep the project on schedule.
Other challenges included attention to the intricacy of sequence (how the plan was configured to make sure there was always the necessary load potential available to not cause any inconvenience to the customers), specific outage dates and the project’s overall size. Crews were spread so far apart that even a small task could take longer than expected because, if the original plan changed, workers would need to gather together to perform a two-minute safety drill.
As part of its work on the project, SEC had to navigate through residential areas and two golf courses. Construction on the golf courses displaced grass. SEC was responsible for restoring areas back to a state equal or better than how they started. In most cases, the company hired subcontractors to complete the restoration according to its standards. Leaving site conditions as good or better was critical as a representation of the business practices of SEC and Duke Energy.
Since this project was not linear, SEC put plans in place to work a sequence based on outage schedules and the engineering sequences. To meet the staffing needs of the various projects, SEC sent multiple crews to hot stick training to ramp up the number of hot crews who could work under energized conditions.
“For hot stick and bare-hand linemen, we look for people who are very focused, who are regimented, so to speak, because everything we do is a step-by-step process,” said Tom Rupp, vice president Energized Operations, Southeast Region, Quanta.
“We need folks who can follow procedures to a T and not get ahead of themselves or ahead of their fellow workers. Not all linemen in our trade are cut out to be high-voltage linemen. The training is quite intense and requires the linemen to demonstrate needed skills and pass a written test.”
At a Quanta training facility in Texas, lineworkers for this project were specifically trained in the bare-hand concept and in honing their skills on how to approach a project using fully energized protocols, explained Jim Bowen, senior vice president, Service Electric.
“During energized work, the procedures are more involved and require crews to keep a minimum approach distance from the energized conductor. Additional planning is always required, and any substantial changes need to be thoroughly vetted and approved by energized supervisors on the project,” he said.
SEC crews used cranes with robotic arms on the ends of booms to perform the energized work. These tools provided a temporary home for an energized conductor while other work tasks were being performed, such as pole change-outs or insulator replacements.
“Once the new conductor was installed, the old conductor was switched out and tested for voltage, then grounded by SEC linemen,” Bowen said.
Both steel and concrete poles, most ranging in height from 80 to 110 feet, were used on the project, as designated by the engineers. Some poles were 130 feet above ground. Poles came in one- and two-piece designs, per the engineers.
SEC set the base foundation, then using approved work methods and procedures, transferred a wire from an old pole to a new pole. When the old structure holding the existing wire was empty, the lineworkers could pull it out of the ground and haul it away, resulting in a new pole with the old wire. On parts of the project, a helicopter was used to efficiently install the new wire, limiting the impact to the neighborhood, as well as to assist SEC in accessing some areas.
“A lot of people think what we do is dangerous,” Rupp said. “I would like to put it in other terms. We work in a very hazardous profession. There are lots of hazards out there. When it becomes dangerous is when the crew involved fails to recognize the hazards or do anything to mitigate those hazards. That’s when people get in trouble. Using STKY (Stuff That Kills You), we build capacity into the process, so if anything were to go wrong, we can fail safely. That’s why we need focused, calm people who can look at the situation and determine what needs to be done. When the procedures and protocols are followed, it’s very safe work.”