From stringline to streamlined
Alabama contractor draws upon an arsenal of GNSS equipment— including a curbing unit — at new recreational site.
Tired of being at the mercy of curbing subcontractors, Jacob Cunningham, co-owner of Cunningham-Delaney Construction (CDC), purchased a GNSS-based curbing machine in 2015. He did so knowing that facet of his operation would at last be under his control. He also was certain that putting down curb and gutter, once a slow and cumbersome stringline process, would now be made dramatically better. The chance to prove it came with a bid to create a major Alabama resort destination called OWA near the state’s Gulf Coast. Faced with a daunting list of concrete pours — and an extremely tight window in which to do them — CDC drew upon the strengths of its new technology to meet the challenges head on. That performance (in many cases doing work in a fraction of the previous time) not only kept the project on track, it totally validated their decision to go stringless.
"We knew that replacing the traditional hand-forming or stringline approach with a Power Curbers Model 5700-C equipped with Topcon Millimeter GPS would position us for a “fast-track” project like this."
Cure for concrete woes
As site contractor for the OWA project, CDC is responsible for all rough grading, water, sewer, telecom conduits, power conduits, roadways, asphalt, finished grade and curb/gutter/sidewalk work. Given the time constraints, it is that last item that, in the past, could have presented a problem.
“This was precisely the type of project we had in mind when we decided to commit to 3D paving,” said Cunningham. “We knew that replacing the traditional hand-forming or stringline approach with a Power Curbers Model 5700-C equipped with Topcon Millimeter GPS would position us for a “fast-track” project like this. In fact, having this capability gave us the confidence to bid this job —and others like it — more competitively.”
The sheer volume of concrete work CDC needed to perform at the OWA site was impressive, to say the least. All told, their work alone included more than 12.5 miles of curb and gutter, 125,000 square feet of sidewalk, and island pours on parking lots with 2,000+ total spaces.
“For those lots, there are more than 100 islands, each with a circumference of about 85 feet, that need to be poured,” Cunningham said. “Keep in mind that none of the islands are flat — they all have high points and low points, and while the dimensions are all the same, the slope and the pitch differ for each one. But, because of the technology we are using, all that data is all loaded into the plan, the machine takes over and the accuracies are never in question.”
Teaming the Power Curbers’ paving strengths with a Topcon Millimeter GPS Paver System brings CDC the benefits of GPS positioning technology with a zone laser reference for both accuracy and productivity. On the islands alone, said Cunningham, what they now do in one day, would have taken them a week to do with a hand-forming curb crew. “Even doing it using stringline would have taken us 2-3 times as long, given all the tedious setup time needed to get the line set,” he said. “That kind of delay would have made it nearly impossible to finish the job on schedule. Going stringless has been a game-changer for us.”
Smaller but more productive
Cunningham’s decision to go with the GNSS curbing approach stems from the fact that so many machines in his fleet — dozers, motor graders, and excavators — were already running Topcon machine control systems, so data could be shared between all parts of the project.
“We’ve been using GPS for almost six years now and know that it allows us to do more with a smaller workforce, and we’re seeing that here at the OWA site,” he said. “Despite the magnitude of the project, we are getting things done nicely with a crew of about twenty. We are using Topcon 3D-MC2 on a John Deere 672-D motor grader doing fine grading for roads, and the same system on a John Deere 700-K dozer.”
A John Deere excavator running a Topcon 3D-MC system was also used to dig two ponds and perform mass cuts to get green spaces down to grade. A single Topcon GR-5 base covered the entire 500-acre site and his crews used another GR-5 with an FC-5000 data collector as a rover. “The team from Earl Dudley’s Birmingham office helped get us into GPS back in 2011,” Cunningham said. “That definitely changed the way we do things and we’ve put all that expertise to work out here.”
"Despite the magnitude of the project, we are getting things done nicely with a crew of about twenty."
By the time their facet of the project wraps up, CDC will have placed more than 6,000 cubic yards of concrete to lay 25,000 linear feet of 5’ wide sidewalk and 66,000 LF of curb and gutter. Cunningham said they have always prided themselves on being a turnkey civil contractor —this newer technology helps them solidify that reputation.
“We still sub out is our asphalt work, but we have control of everything else and we like it that way,” he said. “When we got onsite last year, we had to move a significant amount of soil to establish grade. Then we had to install all the sewer, including a very large pump station and a good deal of off-site sewer; all the water; a massive amount of large-arch pipe for drainage; a pair of box culverts; and more.”
He added that doing all they’ve done with a crew of that size and in such a compact time frame would have been unthinkable as little as ten years ago. Yet it’s quickly become a reality for them.
“The window on the OWA job is extremely tight, but I’m confident we will make it,” he said. “That’s largely been the case since my business partner, Mark Delaney and I started this company back in 2000. We do our homework and we find the right tools to make ourselves better and more efficient. In this case, that meant utilizing the strengths of all the GNSS equipment including the curbing unit to meet our customers’ needs. Need a textbook example of how to make technology work for you? This would be it.”