Dozers are bullies — digging up dirt and pushing around anything that gets in their way — but they are not uncontrollable brutes. Rather, they increasingly are docile machines with precise controls. Utility and site preparation contractors increasingly are making dozers the go-to machines for rough and finish work.
Among the technologies that have tamed these heavy machines is the ground-positioning-satellite system. It gives operators precise and manageable readings of the blade edge so that cutting and leveling is possible within about a half an inch of a desired grade. We are talking 15 millimeters, to be exact, which frankly doesn’t seem possible, but GPS doesn’t lie.
“With GNSS [global navigation satellite system, such as GPS], there is constant input in the grading process. Without individuals setting stakes, a dozer operator can get precise grade information in the cab to five-hundredths of a foot or better,” says Jeff Drake, manager of earthmoving machine control systems for Trimble. He adds that such a fine cut can be produced in six grading passes on average, while an operator without the GPS system needs 10 passes.
Such productivity obviously saves a contractor time and fuel. The precise grading also produces a sounder building site or truer landscape for a property owner. That’s because a GPS-controlled dozer keeps an operator from undercutting a design surface. Such errant gouging can only be fixed by backfilling and packing — a messy and expensive process.
The upshot of this refinement in dozer technology is that “a customer now has more flexibility, operating one machine instead of two,” says Jason Anetsberger, senior product manager for Intelligent Machine Controls for Komatsu America Corp. That is, a customer now has one machine doing both rough and finish grading — a dozer instead of a dozer and a grader.
Grade-control and other sophisticated operating technologies in dozers have two-fold impact on operators. One is that old dogs in the cab suddenly must learn new tricks if they are to fully harness the capacity of new dozers. The instincts and fine motor skills of veteran operators no longer are enough but, to their credit, most are adapting to the times.
“The majority of operators have warmed up to the technology,” says John Bauer, brand marketing manager for Case Construction. “They’ve learned they can be more productive by using it.”
Kurt Moncini, Komatsu’s senior product manager for crawler dozers and excavators, has seen the same. “During our demonstration days, one comment from a longtime dozer operator was that he got a very good feel for taking the machine to its maximum ability. He said even though he had a lot of years of experience, he could never compete with an Intelligent Machine Controlled dozer because control of the machine is so much better.”
The other advantage is that latest generation dozers have intuitive controls even though they are more complex machines. Consequently, they are more appealing to new employees at a time when contractors need every incentive they can find to lure new people into the industry.
“We have heard a lot over the last 10 years or so about owners having a difficult time getting and retaining skilled operators,” says Mark Oliver, product marketing manager for John Deere dozers. “Dozers today are, in a sense, a little bit easier to operate. We need machines that are easier to operate. A contractor today cannot afford to train an operator for three years to become an expert.”
Fully agreeing is Joel Fritts, the market professional for small track-type tractors at Caterpillar. “New dozers are ‘smarter’ today than in the past. This makes them easier to operate. The construction industry needs to attract more employees and make it easier to operate dozers is one way to do that.”
So how does a contractor shopping for a grade-controlled dozer go about selecting one that will best suit him and his crew? Size matters. Most site preparation and utility contractors opt for smaller dozers — weighing 7 to 10 tons with horsepower ranging from 75 to 130 — because of site limitations. They are forming residential lots or subdivisions, after all, not carving away mountainsides.
“Application dictates size,” says Bauer. Horsepower and blade size are the starting points in sizing, with a machine’s dimensions also a consideration. “Transportation capability is something to consider. The larger the machine, the bigger the blade and trailer, and blade width limitations also become a factor. A smaller machine can be transported a lot easier.”
The problem is that “smaller” sometimes means skimping on technology, but that is not the case with grade controls. Smaller dozers generally aren’t missing a thing. “Years ago, that was true. Nowadays it is not,” says Oliver. “Every contractor wants the latest technology in whatever core dozer is used to support the business. So grade control is available on the much smaller machines.”
“Customers do not have to sacrifice new technology features just because the machine may be small in size,” says Fritts. “Actually, sometimes new technology emerges on smaller Cat dozers prior to being offered on larger Cat dozers.”
So, contractors have numerous brand and model options in site-prep, grade-control dozers. For example, Komatsu offers Intelligent Machine Control in its Tier 4 Final D39 series and its D51 models, with engines ranging from 105 to 130 hp.
Geopositioning companies have teamed up with equipment makers to provide the choices. Komatsu’s Intelligent Machine Control is an integrated system unique to the manufacturer, but it incorporates Topcon grade-control components. Caterpillar’s technology for smaller dozers is called Accugrade 3D and was developed with Trimble. John Deere has introduced a 700K “SmartGrade” dozer that incorporates Topcon technology. Case is working with Leica Geosystems in developing integrated grade control.
But other combinations are possible: Dozer buyers can opt for one system over another right at the factory. Oliver says John Deere’s “core grade-control philosophy is, ‘We will not dictate to our customers.’ They have the choice. If they want Trimble, we have a configuration for that. Same with Topcon and Leica.”
Before GPS systems began to be meshed with dozer electronics and hydraulics in a machine’s manufacturing process, the systems were available as aftermarket add-ons. They still are. Drake says both integrated and aftermarket system sales are up at Trimble. “People are now buying the add-on modular units to be competitive, while we are working with all major manufacturers in the United States and elsewhere to integrate our technology.”
One advantage of adding GPS components to a dozer instead of integrating them is that they can be removed from a down machine and transferred to another piece of equipment in a fleet. A disadvantage is that the poles riding the upper front corners of a blade and the lines running to them are vulnerable to damage, and the antenna rising from the roof of the cab invites theft unless removed at the end of each work day.
Today’s amazingly accurate grading systems are enhanced by complementary engineering. For example, Case has something called Advanced Load Management that automatically reduces track speed when the blade is heavily loaded to maintain optimum power and efficiency — a feature available even on the smaller 74-hp 650L model. Caterpillar offers Automatic Traction Control to the same end. Deere’s EcoMode automatically adjusts rpm to the blade load, boosting productivity and reducing fuel consumption.
Together, the advanced technological features produce smooth surfaces bladed to within a whisker of a desired plane. Yet the search continues to wed blades and satellites for even closer tolerances. Says Trimble’s Drake: “Accuracy is addictive.”
Giles Lambertson is a freelance writer for Utility Contractor.