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For more than two years, Wellington has been working on the new Woodrow Wilson Memorial Bridge that will cross the Potomac River near Alexandria, Va., on the Capital Beltway. The Beltway, an eight-lane highway, circles Washington, D.C. The Beltway narrows at one spot: at the existing drawbridge and approaches, which crimp traffic into six. Since the Beltway carries up to 225,000 vehicles a day and the 45-year-old bridge was built to handle 75,000, this squeeze play can become a driver’s nightmare, routinely resulting in backups that are miles long.
The Beltway, part of Interstate 95, the East Coast’s heavily traveled main corridor, has undergone several widening projects, but nothing touches this effort. When completed, the new drawbridge, constructed parallel to the old span, will have a 257-foot wide, 12-lane bascule. The eight bascule sections—the steel leaves that open for boat traffic—are lifted by huge semicircular gears. One of Wellington’s jobs is to provide two 35-kilovolt (kV) primary circuits that are terminated at substations in electrical rooms under the bascule section’s roadbed and routed through a platoon of Cutler-Hammer switchgear to feed the 16, 150-hp gear motors and corresponding bridge controls.
Wiring any job of this scope would be tricky enough, but the majority of this “wire” is four inches in diameter, 1,000 feet long and weighs 14 pounds a foot. It is protected by steel-cable armor, wrapped in tar-impregnated jute and polyethylene jackets, and laid in a trench dug well below the Potomac’s navigation channel. The cable reels weigh 7 tons and transporting them—or any material—to the project site was difficult since trucks had to rumble through Alexandria’s Old Town, the kind of neighborhood rife with commercial restrictions, a slice of real estate full of $2-million-plus town homes and narrow streets once strolled along by Washington, Jefferson, Monroe and Madison.
Scott Winters, Wellington project director, said community relations played a big part in the new Wilson bridge preparations. His construction trailer complex is tucked under the old bridge, along with other job site trailers and staging areas, all hemmed in by Jones Point Park along the Potomac. There is very little room to move, park work trucks or store materials.
On a cold, sunny December morning, Winters and Jim Fuss, general superintendent, led a guided tour of the project. From the top of the new bridge, 20 feet taller than its predecessor, there is a close-up view of Old Town’s wintry streets and nonstop traffic.
“You have two factions here,” Winters said. “You have the state and all the motorists and the commuters that can’t wait for this bridge to open up. Then you have the people who live right there—and I can understand their feelings—they have all this construction that’s been going on for two years, and it’s going to be a five-year period before it’s done. They have to listen to the equipment, trucks rolling down past their beautiful homes, in a very quiet, lovely neighborhood.”
Wellington wins contract
What made Wellington a good choice for the new bridge is the full-service contractor’s financial strength and experience with marine, bridge and traffic-management projects. Besides the submersible bridge-control cable, secondary power, lighting, pedestrian-warning and gate systems, Wellington will install CCTV, a wireless roadside weather information system, remote traffic microwave sensor and fiber optic communication systems, using Transdyn, Pleasanton, Calif., as a subcontractor to design the bridge’s “intelligent transportation system.”
In addition, Wellington was awarded the electrical contract for the $191 million Maryland bridge approaches. President and CEO Paul Loftus said Wellington received $30 million in contracts for both the bascule and Maryland approaches. Loftus said Wellington has changed dramatically over the years through both internal growth and acquisitions, some they have retained and some they have shed, and once had double their current work force.
“We’ve been up the ladder and find the area we’re in now fairly comfortable,” Loftus said, adding Wellington has recently put a marketing firm into the mix. “First, we’re having them upgrade all our business-development materials. I think of marketing as a presentation of what we do and since we do many specialty projects, a lot of people aren’t aware that we’re more broad-based than the conventional electrical contracting firm.”
The bridge-control cable design and installation was the project’s most challenging aspect. Graybar, St. Louis, handled distribution of the Draka Cableteq USA cable, which was custom-made at Draka’s North Dighton, Mass., plant. Steve Stone, a Graybar datacom sales manager who had never worked on submarine cable, said his Pittsburgh branch office normally didn’t chase this type of project. The cable spec came in “volumes,” and he conferred with a Draka team and Winters to get the design just right.
“Large projects like this became a niche market, and I really wasn’t all that familiar with Draka,” Stone said, adding that the cable manufacturer did a lot to make the process smoother. “They understood this product, all the intricacies, and they actually taught Graybar a lot about this product. I doubt there are many manufacturers in the world who could have made the product the way it was specified and the way that it came to the job site. I think Draka had to retool some of their capabilities just so Wellington could make the runs that needed to be made.”
As the cable installation got underway, Graybar facilitated cable deliveries every other day into Alexandria, which, if handled incorrectly, could result in heavy fines for Wellington. Graybar also negotiated copper prices as they fluctuated during the multiyear production process, and helped Wellington lock in a good deal. Stone said this type of job, with its complicated logistics, showcases Graybar’s expertise.
By December 2005, Wellington had installed most of the submarine cables. Since the bridge opening precludes connecting utility lines between Maryland and Virginia, another subcontractor Marine Technologies, Baltimore, cut a trench through the channel using a clam bucket. Wellington’s installation requires that 24 four-inch cables go to the Beltway’s “outer loop” bascule section with nine more to the inner loop section; this is accomplished with assistance from Marine Tech divers.
“In supposedly an orderly fashion—you can’t see your hand in front of your face—once all the cables are in the trench, the divers backfill with gravel,” Winters said.
To handle the cable, Wellington set a huge reel on top of one of the V-shaped bridge piers—or arch rib—where the electrical rooms are located. Dominion Virginia Power provided utility power for the two Wellington-installed 35 kV feeds that run 2,500 feet underneath the bridge approach through six-inch conduits. The feeds terminate in the Virginia-side electrical room.
Ten four-conductor sets of 500 MCM cables, 18 119-conductor bridge-control cables and three 48 multimode and single-mode fiber optic cables continue down through the accessible, hollow arch rib. At the rib’s bottom sits a concrete piling pier with embedded six-inch conduits that are directed away from the bridge and extend into the navigation channel. The cables run down through the Virginia-side arch rib and piling pier across the river channel and up the Maryland-side piling pier and arch rib terminating in the other electrical room. This cabling arrangement provides the power and control systems with total operation redundancy.
“There’s a backup for every operation system that’s in place,” Winters said. “If utility power is lost on the Maryland or Virginia side, we can automatically switch through either substation by means of switchgear interlocks or two standby generators, depending on which side is lost.”
A gold-plated job
As one might expect, the cable management on this project is something to behold. The tray and conduit are not only jumbo sized, they’re top quality. Vibration from traffic—it constantly rattled the Wellington trailer complex—and opening the bascule leaves has nearly ruined the old bridge, and the new one is designed to withstand this endless fatigue for the next 50 years. All conduit is PVC-coated GRC, Winters said, and all cable tray is stainless steel. Pull and termination boxes, enclosures, hardware, are made of 316-grade stainless, and supports are fabricated from hot-dipped galvanized steel.
Once Wellington had negotiated and executed the contracts, Winters spent months preparing outlines, developing goals and assembling a staff.
“We have a lot of layout and design responsibility,” Winters said. “The project’s on-site staff includes two engineers and two superintendents. We spent a good bit of time just developing the different layouts for all the equipment, material, conduit, cable tray to the point where we basically engineered everything on our own drawings.”
Winters said he’s done the gamut in the industry—powerhouses, manufacturing facilities, prisons, hospitals—but this was another experience altogether.
“I’ve either managed or been involved with just about everything in the industry,” he said. “But this is neat. It’s an interesting job. It’s personally the most challenging thing I’ve ever done.”
But most important, D.C.-area commuters and thousands of weary travelers rolling down I-95 won’t have to worry as much about another traffic jam. EC
FULMER is a freelance writer based in Joppa, Md., and former editor of ELECTRICAL CONTRACTOR magazine. He can be reaced at [email protected].