While most government officials clearly understand the importance of providing fiber optics to residents, some still remain a little fuzzy about how those communications lines are actually installed.
It wasn’t long ago that telecommunication companies were focused on installing the fiber optic infrastructure cities would need to supply each home and business with broadband services. Today, the major cross-country fiber optic lines have been installed and telecommunication companies are now working to finish the final step, or last-mile installation, which requires connecting the fiber optics from the curb to the home or business.
There are several methods utility contractors can use to install fiber optic lines, including trenching, horizontal directional drilling (HDD), vibratory plowing and stitch boring with piercing tools. Each method has its advantages depending on several job factors, including ground conditions, size of conduit, length of the run and whether it’s an established or green field area. For example, in green field areas where ground disturbance isn’t a major concern, trenching might be the preferred method for installation because it involves digging an open trench to place the conduit, whereas HDD and stitch boring might be strongly preferred in established areas because they are the installation methods that cause the least ground disturbance.
Oftentimes, when a telecommunications company approaches a municipality regarding fiber optic installation in their area, government officials are ecstatic that they don’t have to use taxpayers’ dollars in order for their residents to get broadband services. Even though the municipality won’t be overseeing the utility construction project, there are several questions officials should ask to ensure the installation process is as stress-free as possible for their residents, says Eric Nicholson, eastern business manager for HammerHead®.
A few questions of those important questions to ask are: Why did you choose this particular installation method? What are its benefits over other installation methods? How will our residents be disturbed by this installation method? Is the chosen method the least invasive? And if not, what are the circumstances that prevented you from choosing a less invasive installation method?
Over the years, city officials and engineers have become savvier about the technological advancements of trenchless and its many benefits. But as technology and innovations continue to advance, one simple and easy-to-use piece of equipment may sometimes be overlooked: the pneumatic piercing tool. Unfortunately, contractors forget about this tool and attempt to complete a simple project with a more expensive or time-consuming alternative process.
Unlike some trenchless tools, pneumatic piercing tools have long been on the market, with patents dating back to 1916, Nicholson says. The tools gained popularity in the 1970s and 1980s and have helped thread the modern utility infrastructure, especially during the fiber optic boom of the 1990s.
How Piercing Tools Work
So what makes using a pneumatic piecing tool the right installation method for the job? Well, first government officials must understand how the tool works and the benefits it offers.
Pneumatic piercing tools are commonly used by utility contractors for the installation of gas, electrical, phone, irrigation and cable lines. The tools create a compact hole ranging from 2 to 8 inches as it is driven forward by compressed air. At one end, an entry pit is dug and the tool is leveled. An exit pit is also dug. Once the air supply is connected, the tool bores on a path parallel to the ground from the entry pit to the exit pit.
Depending on ground conditions, the piercing tool bores about 1 foot per minute with bore lengths typically ranging from 30 to 60 feet. Once the bore has been made, product as large as 6 inches can be placed in the hole. In challenging ground conditions, contractors have the ability to attach the product to the rear of the tool, and in soft soil conditions, the product is generally pulled or pushed into the hole.
“A major benefit of the pneumatic piercing tool is its ease of use,” Nicholson says. “While some methods of trenchless boring require a large amount of training and skill, the piercing tool can be used by a customer with minimal expertise.”
In addition, because the tool can bore under driveways and sidewalks and requires only entry and exit holes, there’s no need to repair or replant existing landscaping.
Stitch Boring: How It Began
The stitch boring method all started in the late 1990s as an experiment by MasTec, a specialty contractor for communications companies, utilities and governments throughout the United States and Canada. The task at hand was to install large quantities of conduit in existing neighborhoods with minimal disruption and then install the fiber conduit. The integrated fiber in the loop project was similar, if not identical, to the last-mile installation projects being completed around the country today.
Much like today, MasTec faced the challenge of finding the skilled labor force needed to operate HDD units. Other challenges they encountered were placing the new conduit along the easement and maintaining the shallow depth requirement while intersecting the phone, water, gas and electric services going to the homes. By utilizing piercing tools, spotting the existing utilities typically at 30- to 50-foot intervals, and shooting the piercing tool from pit to pit, the contractor can then stitch the conduit in the ground in similar fashion as the bores are completed maintaining depth, accuracy and running line.
This is how the stitch boring process became one of the most economical trenchless methods when needing to install large amounts of fiber where finished landscapes exist and short bores are the norm.
NTI Opts for Piercing Tools
For one company, the stitch boring process using pneumatic piercing tools is rarely overlooked. In fact, the company — NTI in Elkridge, Md. — continues to use the tools to install large amounts of fiber optic lines for Verizon. And with a production goal of 50 feet per crew member during each eight-hour shift, NTI needed a tool that could install the lines fast and effectively.
“With experienced five-man crews and good ground conditions, we sometimes see between 325 and 490 feet of production in a shift,” says George Bandurchin, executive vice president of operations for NTI.
The company sets up each crew with air knives, air compressors and two piercing tools. The crew carefully determines the best places to dig small entry and exit pits (about 24 inches deep) for the piercing tools. Each pit is dug using a combination of air knives (air excavators) or hydrovacs and hand shovels. Once the pits are dug, the crew strings air hoses from the compressor to the easements to power the piercing tools. The tools are then connected to the air supply and shot from pit to pit between 25 and 40 feet depending on ground conditions.
“We chose HammerHead piercing tools to do the work because we knew they would be a reliable way of installing the fiber conduit under trees, gardens, out buildings and other permanent fixtures. In addition, there is less restoration involved versus plowing or using a trencher,” Bandchurin says.
Much of the underground fiber to the premises infrastructure is being placed with 3.5- and 4-inch HammerHead Mole piercing tools on the public utility easement and the service drops are installed with 2-inch HammerHead Mole piercing tools. NTI chose the 2-inch tools for service drops to go under sidewalks, driveways and landscaping in order to run service to homes. “Much of the general public’s perception is that utility easements are their own property and although we have permits to dig there, we make every effort to leave the property as we found it,” Bandchurin says.
“We’ve had a few property owners upset that we were digging on the utility easement of their property. However, afterwards these property owners were amazed at how little disruption there was,” he adds.
With an increasing number of last-mile installation projects being conducted in municipalities across the country, government officials are discovering the importance of understanding this type of utility construction. By educating themselves on the different installation methods, they can ask the right questions and learn just how much their residents will be affected, thus alleviating any potential concerns or problems.