- LATEST HEADLINES
- THE MAGAZINE
It only took one project for Reeves Contracting to see their money back after purchasing four machine control systems.
Last October, Reeves Contracting, located in Sugar Hill, Ga., began excavation and grading on a 90-acre landfill site in the Atlanta area. The $12.8-million project involves 1.2 million cubic yards of excavation, construction of 4,200 lineal feet of access road, paving, storm drain installation, clearing, utilities, leachate piping and force main installation.
Reeves handles site development projects and does general contracting. The company has been in business since 1952, and it has grown at a rate of 18 percent to 22 percent per year for each of the past five years-despite the economy’s downturn.
“We’re pretty excited about that,” says company president Eric Young. “Obviously the margins aren’t what they used to be, so you have to grow in volume to offset the low margins. We’re around a $25 million company, growing to $30 million this year. We did the infrastructure for the Georgia Aquarium, the Georgia Dome and the Philips Arena in Atlanta.”
The centerpiece of the DeKalb County project is a 27-acre landfill cell that will have an upper platform and a lower platform. Reeves is placing earthen fill into the cell up to a specified elevation, and that is topped by a 6- to 12-inch layer of clay. A thick heavy-duty polymer liner goes on top of the clay, which in turn is covered by a 1-foot protective layer of sand. The landfill is expected to take 75 years to fill.
“They’re very strict about the levels, quality and performance of the base of the cell,” Young says. “Elevations of dirt fill, the clay liner, the polymer liner (and) the protective sand layer are all going to be measured to the thousandths of a foot. The only way we can do that is by GPS modeling and GPS equipment.”
So last spring, Reeves decided to buy several Leica Geosystems machine control systems, including:
• Two Leica PowerGrade 3D systems, one each for two Komatsu D51 bulldozers
• Two Leica XC 16 PowerDigger 3D systems for two Komatsu excavators
• Two Leica base stations and two rovers, which are rods that can check elevations anywhere on the site.
“I can tell you that the Leica equipment will save us at least $100,000 of survey and layout labor that we would otherwise need a subcontractor for,” Young says. “Between that money, and the savings in machine labor on this one job, the GPS units will pay themselves back.”
The first step in using the machine control systems is to get a 3D digital terrain model of the site. “You take the CAD drawings and the information you receive from the engineer, and you hire a company to do a 3D model,” Young says. “Construction Laser, our Leica dealer, did the 3D model for this site. We put that model into a little computer the size of an iPad-only a little thicker. Then you just snap that computer into a docking station on the machine.”
A display screen in the cab shows the operator in 3D where a dozer or excavator is sitting relative to the site, and the blade or bucket is shown in its precise location. On the dozers, the PowerGrade 3D systems will automatically control the blade for fine grading applications. The PowerDigger 3D systems on the excavators provide a graphic 3D indication of the bucket’s blade at all times.
When it comes to fine grading 27 acres of the landfill cell, Young says he appreciates machine control precision on the dozers. The Leica systems are connected to the dozers’ hydraulics and can automatically control the blade.
“You want to have the entire cell graded to within a few thousandths of a foot, because when you’re talking about 27 acres of clay, it can be extremely expensive if you missed that by even 10 percent,” Young emphasizes. “It’s the same way with the protective sand layer. You could have tried to do this with staking and stringing, but the labor costs would just kill us.”
After the excavators do their work, 10 Komatsu off-road trucks are loaded up. Each truck hauls between 20 cubic yards and 35 cubic yards of earth, and the roundtrip haul distance to the landfill cell is a little more than 4 miles.
“We’re pulling dirt from a site 2 miles away-hauling about 10,000 yards a day-from the mining area to the cell to create and develop the landfill,” Young says. “We’ll cut a little over 1.2 million yards of earthwork to place in and around the cell. The trucks are running 10 hours a day, five days a week.”
Sleeping with a Rover
John Rosier is the owner of Construction Laser, of McDonough, Ga., the Leica dealer who sold the machine control equipment to Reeves. After calling the contractor many times over a period of months, Rosier said he convinced Young to take the Leica systems for a 90-day trial. If Young wasn’t happy with the systems, Construction Laser would remove them and absorb the cost of altering the demo machines.
“At first, I had two systems out there,” Rosier says. “And then we fitted up another excavator, and provided another base and rover. It took some time to get it all installed, but it all finally came through last April.”
Young says before he decided to go with Leica Geosystems, he also tried a machine control system from another manufacturer. “So we had a Brand X system installed on a bulldozer and the other excavator,” he says. “We basically used both systems out there in competition and review for about 60 to 90 days. Each of the operators liked their respective systems. We actually looked at three systems and narrowed it down to Brand X and Leica.
“What it boiled down to was that we evaluated the two systems-what was different about them, the pros and cons-and we did a scope sheet to evaluate all of the different issues and the prices. We interviewed the two suppliers face-to-face in my office, with their representatives. And they came back with some revised pricing and revised information, and then (we) went through that one more time-and we determined that the Leica system was the best system for us.”
One thing Young likes about the equipment is the durability of the computer unit. “The Leica unit is a self-contained and closed unit,” he says. “It doesn’t overheat, doesn’t need a fan or any of that kind of stuff to cool it down.”
What’s more, Young says, is that the Leica computers can be moved from one jobsite to another. The operator on one job simply puts the computer unit in a bag, travels to the second jobsite and snaps the unit into the docking station on another machine. “Snap it in, and you’re up and running,” he says. “It will actually store multiple jobs.”
Young says one of his employees, general superintendent Vernon Smith, initially was opposed to the GPS units.
“He was a believer in the stringline and the conventional method of surveying, and now he sleeps with a rover,” Young says.
“He just cannot get over the amount of time and effort those GPS systems have saved. Instead of calling the surveyors and waiting for them, he can just go out there and set down the rover and know whether that elevation is within a foot, or 2 inches, or 10 feet. He actually called to apologize for opposing the GPS units and says he wouldn’t live without them anymore.”