You’re reading an outdated article. Please go to the recent issues to find up-to-date content.
Despite the unsteady state of the nation’s economy, the telecommunications industry continues to expand with broadband services as the primary driver.
“Even amidst the uncertainty, we expect the telecommunications industry to continue growing,” said Robert Rosenberg, president of Insight Research, a research and consulting firm specializing in telecommunications. “Telecom is as necessary to development as roads and bridges, so it is expected to fare much better during recovery than other economic segments that may take longer to return to normalcy.”
Nearly all of the growth is expected to occur in broadband services, Rosenberg said, commenting on findings of an Insight Research study released in January 2010. The report estimates that wireless broadband service revenues are expected to grow at a compounded rate of more than 62 percent over the forecast period, while wireline broadband services will grow at a 6 percent rate over the same forecast horizon.
Broadband demand is strong because the United States lags far behind other nations in broadband deployment. Deployment of fiber to end-users is proceeding but slowly, with Verizon the only major carrier providing fiber to the premises (FTTP) connections to end-users. Most high-speed Internet customers continue to be connected to fiber networks with twisted-pair copper or coaxial cables.
However, businesses, government agencies, educational institutions, and other organizations must have high-speed fiber networks, and some are turning to private fiber networks built to suit their specific current needs and accommodate future growth. Private networks also are bringing fiber optic broadband to rural areas that major carriers find uneconomical to serve.
Electrical contractors active in telecommunications work aren’t limited to premises wiring but can use their capability to do outside plant construction to offer their services to turnkey projects.
Broadband deployments include overhead and underground outside plant segments, with anecdotal information indicating the amount of underground is increasing.
“Our projects are a mix of both—about 70 percent aerial and 30 percent underground,” said Robert Unger, division manager of the communications division of O’Connell Electric Co., Victor, N.Y., a firm active in telecom work for about 20 years; it established a separate telecommunications department in 1996.
“Each aerial job typically does have a piece of underground, as well, for building [the] entry point to the customer’s premise. I would not say there is a not preference for installing cable either overhead or underground. It is what is applicable for each project. For example, on a few wind farm projects we have completed, the fiber between turbines typically is direct-buried or put in schedule 80 PVC duct, but as the distance between turbines grows, the more often it will be aerial to help keep the cost down,” he said.
Unger believes the potential amount of underground work is growing.
“With the ever-increasing need for broadband, I hope that, as communities design these systems, they will also design them for the future,” he said. “And in doing that, if you build an underground pathway system, that should make it more cost-effective to put in more strands of fiber in the future. That is accomplished by installing empty tubes so that, in the future, a small crew can ‘blow’ through fiber versus needing large, multiple crews and equipment to install aerial fiber.”
O’Connell Electric is a full-service electrical contractor that can perform all aspects of aerial and underground construction required with its own crews. The company also has registered communications distribution designers (RCDDs) on staff, which have design and engineering abilities, and a work force of technicians for the construction. In most broadband projects, design work is design assistance to a consultant or end-user, rather than a complete design from the beginning.
Unger said, with outside plant projects, O’Connell Electric typically also installs cabling and components inside buildings.
“That may not be common for all contractors,” he said, “but, because we have a large line department and a communications department within our company, we do try to offer turnkey solutions to our customers.”
Methods of Underground Construction
Contractors use several methods to install underground telecommunications cable, including fiber optic cable for new broadband networks. The two most used procedures are trenching and horizontal directional drilling (HDD).
Dig a trench, put cable or duct in the bottom, fill up the trench—for years it has been the fastest, least costly method of burying utilities. Trencher models range from compact walk-along machines for services to big, powerful models that can dig a trench wide enough to accommodate bundled duct. However, surface improvements and crowded easements today may make trenching difficult, impractical or impossible.
This versatile “trenchless” procedure installs cable and duct under streets, sidewalks, driveways, landscaped areas and other obstructions. By minimizing excavation, restoration costs can be greatly reduced. An HDD unit drills a pilot hole, and cable or duct is pulled back through the hole. The variety of sizes and capabilities of HDD equipment available today allows directional drilling to install underground services to end-users as well as feeder lines and “middle mile” cables to the supplier’s network. Installed per-foot costs for HDD are higher than open-cut, but savings resulting from reduced restoration costs often make HDD the more cost-efficient procedure.
This variation of open-cut construction is new to the industry and has yet to be used on a large scale. However, developer Quanta Services believes it offers significant benefits for FTTP projects. The microtrenching process uses a specially equipped disc-type trencher to cut sub-inch-wide, 12-inch deep trench in asphalt as a self-contained vacuum system cleans the trench of spoil. Conduit is placed in the trench, which is filled with a proprietary grout that will not shrink, weather or erode. Sealer is applied after the grout has cured.
Other underground construction methods available include vibratory plowing, unguided boring, “stitch” boring and vacuum excavation.
A popular method of installing telephone cable for decades, vibratory plowing is not widely used for broadband deployments. A plow has a vibrator that oscillates the blade vertically, and this movement separates the ground in front of the blade, reducing the force required for the blade to cut the ground as well reducing resistance on the sides of the blade. Cable or smaller-diameter duct feeds through a chute in the blade into the ground. Larger duct is pulled into the ground. Reduced surface damage is a primary benefit of the process.
Compact hydraulic boring tools—usually mounted on a host vehicle, such as a trencher—can make short bores under sidewalks and drives. Long bores are considered impractical because there is no way to control the path of the tool.
With stitch boring, a pneumatic piercing tool literally pounds itself through the ground to make short bores under driveways and other obstructions. Although some contractors have used the method extensively, the inability to control the tool is a problem and can pose risks to nearby buried infrastructure.
A versatile vacuum excavator can make “soft” excavations using high-pressure water or air to displace the soil. A vacuum excavator can quickly dig short trenches in areas where larger equipment cannot go. A crew member simply extends the high-pressure water or air hose and makes the excavation, as another crew member uses a vacuum hose to collect spoil.
For underground, excavation and horizontal directional drilling (HDD) are the primary methods of construction used.
“We are equipped with both trenchers and HDD equipment,” Unger said. “That is not to say we do not subcontract out this type of work because at times we do. It depends on the scope of the project and our work load at the time of the installation. We do have subcontractors that we, as a company, have prequalified, and one of our subcontractor partners is typically ready to go when needed.”
Methods of construction depend on the project requirements and soil conditions.
“Each underground project is unique in its own way,” Unger said. “In New York state, there is quite a difference between working in the Rochester area and working in the Adirondack Mountains. Environmental studies of the soil and rock will typically allow us to know what should be the best applications for completing underground segments.”
Companies in the Houston-based Quanta Services organization have wide telecom experience and have been constructing private fiber networks for several years.
“The market for construction of private fiber networks is growing,” said Ken Trawick, Quanta president of telecommunications and cable television operations. “The need for high-capacity bandwidth drives this demand. A recent analysis of the telecommunications industry documented that enterprise firms and other private and public organizations that depend on secure broadband networks need direct point-to-point fiber connections between multiple locations and do not want to be part of a conventional switch network.”
Several companies specialize in the design of the networks, oversee construction, and, occasionally, own and manage them.
In most instances, Trawick said, building a network is simply executing the project as it was designed. Aerial and underground segments are defined and, for underground segments, contractors usually have few options about methods of underground construction to use. They are specified in bid documents.
“The contractor’s job is to build the network as designed,” Trawick said. “Because Quanta can provide engineering services, we may become involved in planning by making recommendations about construction, but once engineering is complete, the construction process is the same as building a system for a major carrier.”
Whether the outside plant is aerial or underground depends on its location and requirements of the project owner.
“In our experience,” Trawick said, “most private fiber projects have been in urban or suburban areas. Architecture and other considerations, such as redundancy requirements and security, are factors considered in whether the outside plant is aerial or underground.
“Availability of utility poles often is a factor. In many areas, poles have reached their capacity, and joint use is not an option. In those situations, new aerial distribution pole lines are rarely constructed—underground is more cost effective. It depends on the network. For example, security and redundancy may be important for a metropolitan school district, but they are critical for hospitals or defense department and homeland security facilities. Underground infrastructure is less vulnerable to weather-related outages and other damage risks,” Trawick said.
Demand for private fiber networks offers opportunities for contractors experienced in telecommunications work, Trawick said. Construction of the networks is the same as for projects for major carriers.
Underground fiber may be installed in several ways.
“In most cases, conventional methods are used,” Trawick said. “It may be open trenching, HDD or installation of cable in existing conduit systems. Plowing is not a consideration in congested areas. Quanta has developed a new microtrenching system, which we believe has great potential.”
The same could be said for the potential broadband installations hold for those electrical contractors who seek them out.
GRIFFIN, a construction and tools writer from Oklahoma City, can be reached at [email protected].