New power projects are essential to keep vital services and equipment running and prevent power outages. Utility companies increasingly must work with community groups and government agencies to accommodate a broad range of concerns before they can build new facilities. One of these issues is how to aesthetically screen unsightly structures from neighboring eyes.
For the United Illuminating Co. (UI), building a new substation in Trumbull, Conn., included striking this delicate balance between accommodating local homeowners' needs for a visually appealing fence and keeping a lid on costs.
UI recently embarked on an ambitious systemwide upgrade to its transmission and distribution equipment. One part of the 10-year, $1 billion effort started in 2007 was to update the Trumbull Junction switching station in Trumbull, Conn., an affluent community near Bridgeport, into a modern substation.
To help preserve the neighborhood's ambience, area residents requested that UI build a 17-foot architectural wall around the property to minimize the new substation's visual impact. The challenge was how to build it.
Although UI had installed two other architectural walls at other sites, neither was like the proposed Trumbull project. Engineering a wall higher than 14 feet would normally require a much wider footprint to stand up to necessary wind loads, soil conditions, seismic factors, weathering, and other conditions which would consume valuable space and add costs. Finding materials that would continue to look attractive after years of harsh weather would also be difficult. Ongoing maintenance such as painting and repairs would further drive up expenses.
Eugene Kallaur, transmission and substation projects director for UI, had anticipated the need for an architectural wall early and researched options. UI had contracted with Black & Veatch for the Trumbull substation's engineering, procurement, and construction.
A colleague showed Kallaur a similar wall used in a project in Oregon that Kallaur liked. Superior Concrete Products of Euless, Texas, built the wall in Oregon.
Design scores points
Superior's precast concrete products are constructed from modular interlocking panels and posts made of high-performance fiber mesh and steel-reinforced concrete. Each piece is integrally colored in one of several tones. Their tongue-and-groove design makes installation easier and faster than other types of walls and fences.
I-shaped posts are set into concrete piers and aligned 5 feet apart. Matching panels (5 feet long by 1 foot high) are manually inserted into the molded-in post groove to form an interlocking wall. Precast trim caps are textured to match the wall, and are laid on top of each post to provide a finished and distinctive look.
Superior's turnkey services include designing, manufacturing, and installing modular screening walls, security fences, sound barriers, and rail fencing in a variety of colors and textures. Finished on both sides to look like high-quality wood, real brick, or hand-laid stone, precast concrete is stronger than any of these options, providing seamless beauty and the ability to withstand harsh wind, soil, and thermal movements.
It's impervious to termites and cannot rot or burn. Because precast concrete fencing is modular, it's also fast and easy to install, move, or expand. Maintenance costs are minimal. Pigment is mixed with the concrete so painting or refinishing is unnecessary.
One other key advantage the precast concrete system offered was height. The manufacturer's product could be extended above 14 feet without widening the fence's footprint. To build above 14 feet and maintain strength, Superior replaced its standard concrete posts with steel I-beams, which allowed them to build higher within the same footprint. The steel posts conform to ASTM A615, grade 40. The panels attain a strength of 5000 psi at 28 days. Superior's noise reduction characteristics are equivalent to masonry as a reflective sound barrier.
The area residents chose Ledgestone finish in a Pueblo color, which simulates natural stonework. Superior also integrated two custom double truck gates at either entrance to the station which were mounted on special hinges to support their weight. Each truck gate incorporated a smaller pedestrian gate that allows workers to enter without having to open the larger truck gates. The entire fence project was completed in 62 working days.
UI further softened the substation's exterior by surrounding it with Mountbatten Juniper trees, which, when mature, will help camouflage the facility.
“Our goal is to build substations to the requirements that are ordered,” says Kallaur. “Superior worked very well with us, and they did an outstanding job.”