Grading with GPS

By Steve Hudson | September 28, 2010

GPS machine control is making significant inroads in the site work and infrastructure construction field, and Sarasota, Fla.-based site work contractor KLM Services is one of the growing number of contractors who are adopting the new technology.

Established in 1998, KLM Services focuses on site work and infrastructure construction for commercial and residential developers in southwestern Florida.

"Most of our projects are subdivision developments with 50 to 100 lots," says KLM Services founder and president Ken Murphy, adding that the company also handles larger subdivisions as well as commercial projects too.

To help his crews complete such projects with the precision and speed that developers expect, Murphy and his project supervisor Jon Fuller recently made the decision to add Leica GPS-based machine control to several of the machines in the company's fleet — and they have been very pleased with the results.

Murphy admits that he was "kind of old fashioned" and even a little bit hesitant when it came to adopting GPS-based machine control technology.

"We were initially skeptical about the savings that such systems promised," he says, "and I thought about it for several months before deciding to go with it. It was a big step and a big investment for us," Murphy says — but after outfitting several of his machines with the new technology he's now quick to say he's become a believer.

Working with Matt Canfield of local Leica dealer LSR, Murphy initially acquired two GPS-based machine control systems — one for a Cat motor grader and one for a Cat dozer — plus one base station.

"It didn't take us but a day or two to figure out that adding the GPS system was the best thing that had ever happened to us," Murphy says.

Soon thereafter, based on that initial success, he quickly added a third system on another Cat dozer.

One major impact of the new technology, Murphy adds, was the GPS system's immediate impact on how he allocated his personnel.

"Before we added GPS," he says, "we typically had three people on each crew just checking the grade line." But GPS machine control allowed him to "save the cost of three people."

"Those three folks are now free to handle other things on the project," he says.

While getting used to the system, Murphy initially made occasional checks using traditional surveying techniques.

"But as we gained confidence it," he says, "we quickly found we didn't even need those occasional checks any more."

Another benefit of GPS machine control, Murphy says, has been a significant increase in the speed with which grading can be completed, he says.

"Previously, the grader's speed was limited by how fast the grade checkers could work," he says. "Now the grader can operate up to speed."

Overall, Murphy is extremely pleased with the way that the system is paying off.

"It has probably cut our grading time in half," notes Murphy, adding, "At first we just wanted to use the system to do cross slopes, but now we are using it for everything. And we don't have to worry about setting up or knocking over stakes."

KLM Services' GPS machine control system is proving its worth on one of the company's current projects. On this job, the contractor is handling site work and infrastructure construction on a large residential development totaling about 1,150 acres. The development includes 197 lots averaging about five acres apiece, several miles of road construction, and construction of some 37 lakes and ponds. It is one of the largest projects that KLM Services has taken on,Murphy says.

"At first, we just wanted to use the GPS system to do cross slopes," he says. "But now that we know what GPS can do we're using it for the whole thing."

One of the biggest challenges on the project has been construction of the project's eight to nine miles of roadway as well as about 90,000 feet of drainage swales.

"That's where it really saved us money," he says, adding that his crew used GPS-equipped dozers to quickly rough-cut a site and then brought in the GPS-equipped grader for fine cutting.

"The dozer initially prepared the sites very accurately," he says, "and then the grader only had to move a very small amount of material to achieve the final grade."

On the roadways, he adds, the grader's side shift capability further enhanced fine-grading efficiency.

"When all was said and done," he says, "we figure we are saving 50 percent of our time."

Murphy is pleased with the results he's seeing from his GPS system.

"Construction has made some unbelievable strides in technology in the last 10 years," Murphy observes, "and in this business you've got to change with the times if you're going to succeed."

He adds, "When we first went with the GPS system, it was hard for our operators not to grab the machine handles. But now we wouldn't trade it for anything."