A classic from worksites

Criteria of equipment selection—including power, size, blade and attachments—vary in accordance with different operating necessities and types of soil

One of the most traditional equipment for construction, motor graders may carry out a wide range of services. Due to this reason, they are indispensable in infrastructure works—mainly in heavy construction—for example in soil leveling or earthmoving in roads and dams.

In addition, these machines are also used to create inclined surfaces, to finish ramps and slopes, to carry out disaggregation, spreading and transport of material, as well as to open shallow draining trenches with sloped cross sections. Other applications have also to be considered. Recently, these machines started to be more and more used in the agribusiness, especially in building and maintaining access roads to crops and pastures, as well as in building contour lines, quite used in planting. This multipurpose equipment is also used in soil preparation for seeding.

Due to these reasons, selection criteria of ideal size and model vary in accordance with the different needs. And to attend each application, the manufacturers of motor graders make available a wide range of models with different size and power. But according to Esio Dinis, product expert from New Holland Construction, this type of machine is mostly classified by engine power. “Our models available are the RG140 (140-160 hp), RG170B (178-205 hp) and RG200 (205-219 hp)”, says him. “But it is important to point out that our plant located in Contagem (MG) is responsible by the world production of all motor graders of the brand. In other words, it is the global supplier of this family.”

Deepening the analysis, Case CE’s expert Gleidson Gonzaga points out that the market of these machines is composed basically by three power ranges: up to 160 hp, from 161 to 190 hp and above 190 hp. “The first group includes machines with operating weight starting from 12 t, in the second, machines above 14 t and in the third, above 16 t”, explains him. Confirming this sectioning, John Deere also sells three models of motor graders in Brazil, including the 670G (155 to 205 hp), the 672G (175 to 215 hp) and the 770G (185 to 250 hp). “All models have differentials such as filter banks, dumping radiators and simplified adjustments in the wear strips of the circle and of the blade frame”, adds Roberto Marques, sales director from John Deere Construção e Florestal.

Following its competitors, Caterpillar also makes available three models to the Brazilian market: 120K, 140K and 12M. “The first one is leader in its range, with operating weight of 14.3 t and engine power that may reach 145 hp using the VHP (Variable Horse Power)”, says Pablo Ribeiro, motor grader application expert for South America. “Next is the model 140K, with operating weight of 17.3 t and power of 191 hp when using VHP. And the model 12M is enlarging its share with its operating weight of 18.4 t and power of 213 hp when using VHP Plus.”

SPECIFIC FEATURES

In spite of their power centrality, all these models obviously may be configured for specific works. According to Ribeiro, Caterpillar has also available a wide range of attachments to be used in each type of work. “The application of the equipment is what defines the configuration and the attachments to be used”, explains the expert. “Therefore, the analysis of the operation guides the indication of weight and engine power of the machine, if AWD traction is needed, what tires have to be used and what specific attachments—such as center or front scarifier, rear ripper, among other dozens of possible options—will be used, depending on the work to be carried out.”

According to Marques, modern motor graders have configurations that make easier their operation, increase productivity and reduce maintenance costs. Plant-supplied items such as automatic differential unlocking—that protects the equipment when steering in curves—and transmission with smooth changes of speed—what improves finishing services—are examples of this evolution. “Another point of highlighting is the front-axle drive of the model 672G”, says him. “The traction force in the blade of this machine is approximately 45 percent above all models of the same size with traction only in the rear wheels”, says him. “That is why it delivers a higher production in any application.”

In Case CE, motor graders of the 800 Series B family – models 845B, 865B and 885B – are differentiated by their engine power and operating weight, as explains Gonzaga. “In addition, they have five options of front attachments, three options of blade, five cab options and two options of rear attachments. This allows the client to find the ideal configuration for each type of application”, adds the executive.

Talking about New Holland, Dinis says that their models are versatile enough to attend most variable clients and areas of application. In the comfort feature, there are different cab options (high or low, opened or closed). “In the functional aspect, options may vary from the size of the main blade to other attachments such as rear ripper, scarifier, front blade and front counterweight”, points him.