Most earthmoving contractors agree that 3-D grade control systems are the future, but it’s critical to choose the system that best matches your operation. These systems can receive signals from GPS receivers, lasers, or total stations and operate in either an indicate or a fully-automated mode. We talked to several contractors about how these systems work in their operations.
A mixed approach yields savings
Neri Contractors and Excavators, based in Lake in the Woods, IL, is a 29-year-old earthmoving business that runs 156 pieces of heavy equipment, including 50 scrapers, 35 dozers and 11 backhoes. Projects range from 30,000 to 3,000,000 yds.
The company is entering its fourth season with Topcon 3D-GPS+ systems. “We started out with a [Caterpillar] 14H motor grader and a D6R dozer,” says Bill Neri, owner. Both systems were automated.
Now the company uses a combination of indicate-only and fully-automated Topcon 3D GPS+ grade control. “I probably have better than $800,000 invested,” says Neri. This includes indicate systems on eight scrapers, primarily Caterpillar 627E and 627F models. The Caterpillar 14H and 140 motor graders are outfitted with Topcon automated grade control systems. Three Caterpillar D6 dozers and a D5G are also fitted with GPS. A D8R is set up with an automated system and a D8R and a D9R are fitted with visual only.
The D8R was automated as an experiment. “We automated one of them and one of them was visual to see the difference between them,” says Neri. “The operator who runs the automated one says he uses it probably 25% of the time [in automated mode] and 75% of the time he is watching the screen.” This led Neri to the conclusion that the smaller, fine grading tractors should be automated and the larger tractors do not need automation.
The last two finish dozers purchased by Neri were custom-built D6R LGPs with six-way angle blades. “The D6R Series was never built as an angle dozer in an LGP version,” says Neri. “The machine is basically a finish grading machine. It does slope and pond work.” These dozers are equipped with indicate-only Topcon GPS+ systems.
The decision not to automate these dozers was due to the skilled operators. “A lot of the guys I have are pros at finish grading,” says Neri. “These guys can grade in second gear, wide open. With the automated system, there is a fine line on how fast you can speed the hydraulics up before it gets jittery. If you automate it, that actually slows the machine down as far as forward speed.”
You must balance accuracy vs. speed. “The slower you go, the more accurate the system is,” reports Neri. “I run the 14H grader myself a lot. I find I do not use the fine grade automation until I am doing the final pass. Then I will kick it down to idle in second gear just to let it think for itself.”
Neri admits deciding which units will use an indicate-only vs. an automated grade control system is often based on preference. “Everything revolves around opinion,” says Neri. “If you are going to consider automation, I would definitely think road graders and these D6 and smaller dozers simply because of the fine grading. On my automated dozers, the guys find they will bring it in within a tenth or two by visual only. When they come back and do that final cleanup pass, they will put automation on it.”
The move toward 3-D grade control systems has been driven by the cost savings. “We have not seen an increase in the price of moving dirt for 10 years,” reports Neri. Competition has kept the price depressed.
Despite this, Neri has maintained his profit margins. “My profits today are the same as they were 10 years ago. We are working for the same unit price, but we are actually moving the dirt more efficiently. I have probably seen up to a 30% increase in production with the dozers,” says Neri. “A lot of companies just do not realize how much time it takes for staking and re-staking.”