A few decades ago, it would have been science fiction. Satellites orbiting the Earth tens of thousands of miles away send signals to guide machines carving the earth’s surface below with centimeter accuracy.

Satellite positioning technology is sweeping into the construction industry, answering some of the pressing issues faced by contractors and developers – rising costs and finding skilled operators. Some challenges remain for this fast-evolving technology, but manufacturers and end-users alike see productivity gains ranging from 25- to 100-percent with machine guidance and control using satellite positioning.

Though not replacing the operator, the science as the name implies provides “guidance and control” of the business end of the machine – the blade or bucket. With exacting accuracy it adjusts to changes in a downloaded, 3D-design plan in the form of a CAD file. Operators can use its information as they guide their machine, or it can be integrated into its hydraulics, to control the position of the cutting edge.

“With AccuGrade fully integrated into our CAT machines, we are placing the survey, stake-out process, and the design plan into the machine. From a safety perspective we have been able to take the grade checker and put him in the cab out of harms way,” said Tom Bucklar, Caterpillar North American Region Manager, Machine Control and Guidance Division. “From Caterpillar’s perspective, this is not the job site of the future, it is the job site of today and this is definitely where the future is going in construction. We are the only OEM to have designed these technologies into our machines and now have AccuGrade available across our product line. CAT is committed to moving the industry forward with these technologies.”So are other technology developers.

So are other technology developers.
“We are experiencing the biggest change in the history of development since the Industrial Revolution,” said Murray Lodge, Topcon’s national sales manager for construction products. “It’s changing the way that contractors do business. Widespread use of these highly productive systems is enabling the delivery of prepared sites to developers within compressed time schedules. Machine control systems speed up the work processes, making each operator and machine more productive. It not only saves time, but it is actually the closest thing there is to creating time.” (Topcon is one of the leading manufacturers of machine control systems that operate with satellite positioning technology.)

Pat Ruelle is business development director for McAninch Construction of West Des Moines, Iowa, a $200 million company with a fleet of 450 pieces of equipment. It has invested $7 million in GPS systems. The specialized technology systems can cost from $50,000 to $100,000-plus, but it isn’t just for major companies like his. “I think it’s even more for the small guy, ”states Ruelle. “If I had a $25,000 dozer, I would put a $50,000 piece of this equipment on it, no question about it.”

Not Quite Stakeless – But Close
Layout and grade staking are time-consuming tasks that can represent a sizeable percentage of a construction budget. After grading is completed, the site must again be checked for conformance to design grades.

In conventional grading, a construction survey crew sets wooden stakes into the ground on a 25- or 50-foot grid so the machine operator knows where to cut and fill. To get to fine grade, a checker walks with the machine using hand signals to communicate with the operator.

“With this technology, the operator now knows where he’s at on every millimeter of the job site, not every 25 feet,” Bucklar said.

Some stake and grade checking may still be required for mass earthmoving and initial site grading.

“You don’t eliminate stakes but you significantly cut back on their number, anywhere from 50 to 90-percent of them,” Lodge estimates. “You always want to start off the day checking to make sure you are at the correct grade, and have some periodic checks as well.”

Worth the Money?
The obvious plus for purchasing a new system is efficiency, with reports of anywhere from 25-to-100-percent increase in production. Even at 35 percent, a system can quickly prove its worth.

“For example,” reveals Bucklar, “take a warehouse- or Home Depot-sized job, generally for a contractor that is a $110,000 or a $120,000 worth of surveying or engineering costs. “A company can save $70,000-plus on just the surveying and engineering. That pays for the system, and the company is off doing another job making more revenue and being more competitive.”

“Today, the small guys as well as the larger contractors can also see a big impact on their bottom line,” Lodge said. “If they can do jobs in a third less time, they can physically do more jobs a year. Maybe they bid a job at the same amount that they did before, but now all of a sudden they increase their bottom line profit by more than 30 percent.”

Getting the most out of machines is also important in these days of high fuel prices. If the project gets done faster with less down time and reworking of areas to achieve design grade, fuel consumption is reduced. But the advantages go still deeper.

“The Environmental Protection Agency (EPA) is not messing around; no one gets any leeway with the enforcement of the Clean Water Act, which is erosion control,” Ruelle said. “That means the longer the site is open and the longer you are working on it, the higher the risk goes of an EPA violation. The costs for soil erosion controls to the owner can be just outrageous.”

According to Ruelle, the technology mitigates risk for everyone involved, he said. “It allows us to hit the spec exactly the way the tech designed it.”

Additionally, says Ruelle, the technology offers some level of insurance against engineering or design mistakes.

“Once we download that file, we can travel that site and look for spikes in the plan or look for things that don’t work, or look for busts in the topo,” he said.

“Take a job like spreading stone for a large parking lot and you can see a savings. Too little stone aggregate and you invite future failure and outrageous amounts of money to correct; too much and it cuts into your profit margin, he said.

Operators
“Very skilled operators are harder and harder to find,” said Dan Drescher, Crawler Product Marketing Manager - John Deere Construction and Forestry Division. “This type of technology makes the machine extremely easy to operate and very productive in most of their finish and grading operations.”

According to the research at Topcon, Lodge said operators tend to let the leading edge of the blade bite more than the trailing edge to avoid undercutting. “Then he has to go back and drop the trailing edge. It takes him two passes,” he said. “With 3D grade control, you reduce the number of passes to get to grade.” The operator also knows where his cuts are and where the fills are, so the dirt gets moved right the first time.

Final grading can be the most strenuous and fatiguing part for the operator, according to Bucklar. “The operator is feathering that joy stick 50 to 90 times a minute to make sure the blade is exactly on grade and exactly where he wants it,” he said. “A lot of fine graders try to do it in the morning when they are fresh and do a lot of the production and heavy dirt moving later in the afternoon when they don’t have to be as exact.”

By going with the automated system where the technology takes control of the hydraulics, you eliminate that high-fatigue, high-stress part of the job. And, job site safety is greatly improved. The operator can focus on guiding the machine without constant attention to cutting edge controls. Fewer people are involved in providing grade control information in the operational zones of the machine.

Still Not Perfect
One challenge to the use of the technology is getting 3D designs ready to download into the machine control systems. There is no standardization. Currently there are translation programs that can convert the CAD files to work in the various systems. Contractors either have in-house staff to convert them, or they ship it out to a third party for conversion.

It is an onerous process, according to Ruelle who called it perhaps the main constraint against the technology because of the cost to train and invest in the people to utilize the technology properly.

“We’ve been trying to get the word out that it makes sense for the industry to standardize a file format. Whether it’s a DOT, or an engineering company or a contractor, we need to make sure we are all speaking the same language.” Bucklar said. “We all could do a better job to make that more of an efficient part of the process.

A bigger problem he said is that engineering companies and the DOTs don’t provide complete files.

“They either provide paper format or they provide incomplete three-dimensional files. They haven’t seen the need to really spend the time to have a complete, full, three-dimensional file that can be put into the machine.”

One software development company catering to the land development industry, Bentley Systems, is already introducing interoperability components to erase the problems just detailed. In fact, at its annual conference held last month, Bentley executives illustrated their CEI (Construction, Engineering, Inspection) software technology that allows native design data to be taken from a PC to survey instruments for inspection and stakeout operations. The inspection and stakeout information can be sent directly back to the desktop for as-built information.

Bentley also provides for easy export to the leading companies in GPS machine control technology such as Trimble, Leica, and Topcon.

Another issue is access to those “birds” in the sky. 

“In the United States, some people are going to see times of the day where you are not going to pick up five satellites,” Lodge said. “You are going to have downtime. Then if you throw in working around trees and buildings, it’s only going to be worse. Access to GLONASS satellites in addition to GPS satellites — as well as future satellites — virtually eliminates these issues.”

Bright Future
A lack of skilled labor, market competition, and rising energy, insurance, and other costs are the common complaints Bucklar hears from customers.

“You will see more tie-ins to safety features; you will see it become much more efficient and productive where they tie into engine load, hydraulic load, track slip,” he said. The automation can take over more of the dozing cycle to get maximum push. “Those kinds of things help our contractors with skilled labor shortages because they can take a good operator and make him much better, much faster,” he said. “They help with safety because it gets more guys off the jobs site.”

Lodge sees the technology becoming more ingrained in total management of companies.

“They could go around in a vehicle and topo a site quickly and compare it to the week before,” he said. “They know exactly how much material has been moved.”

Drescher concludes that “most of the customers I’ve talked with said that grade control systems will be the growing thing within the industry. There are industry estimates that indicate the use of technology within our industry will grow at 30 percent per year. It will out pace the growth of the industry in general.”  SLDT