Technology brings new efficiency to earthmoving

By Dwight J Roberts

Caterpillar recently introduced a number of new machines – the K-Series Motor Graders and D6R Track-Type Tractor – to Asia/Pacific markets, along with a range of Cat AccuGrade grade-control systems, which help operators attain specified grades faster and more accurately.

The K-Series Motor Graders - 120K, 12K, 140K and 160K - are variable-horsepower machines that range in maximum net power from 108 to 151 kW (145 to 205 hp) and feature a robust design capable of tasks from heavy construction and ripping to road maintenance and fine grading. The new motor graders use the Cat C7 ACERT engine (compliant with EU Stage II emissions regulations) and a durable direct-drive power-shift transmission.

The D6R, with a maximum power rating of 145 kW (195 hp), is an exceptionally strong machine that is easily serviced and tolerant of lesser-quality fuel and oils. Built for durability and reliability, the D6R features the Cat C9 ACERT engine (Stage II compliant), a 3F/3R power-shift transmission, single-lever control and either an LPG or XL undercarriage.

Cat AccuGrade systems significantly enhance the efficiency of these new machines, allowing the operator, when establishing critical grades or spreading expensive fill material, to work without conventional grade stakes. Time and expense for placing grade stakes is virtually eliminated, as is the need to continually check the operator's work. These systems, interacting directly with the machine's hydraulic system to control blade movement, enable operators to attain grades in fewer passes compared to traditional manual control, resulting in saving time, fuel and machine wear.

The potential savings these new products bring to earthmoving projects was recently illustrated during a production study in Thiruvallur, India. A Cat 120K motor grader, equipped with an AccuGrade Cross-Slope System, constructed two identical, 82-metre long sections of roadway, first under manual control, then with the AccuGrade Cross-Slope System. The results were significant. Under manual control, the 120K required 93 passes and 3.03 hours. With the AccuGrade System, however, only 37 passes and 1.55 hours were required - a 49-percent time saving and a subsequent fuel saving of 45 percent.

Caterpillar designed AccuGrade technology to be 'scalable'; that is, to allow machine owners to use only the degree of grade-control technology appropriate and economical for typical applications, but to scale up if operating situations change. Motor graders with the cross-slope system, for example, also can be equipped with a sonic string-line sensor, allowing automatic elevation control at one end of the blade and cross-slope control at the other.

If a motor grader or track-type tractor is used primarily for flat or simple slope work, AccuGrade Laser Systems allow precise grading of level, single-slope and dual-slope contours, again without the help of grade stakes or grade checkers. A laser transmitter, located on site, works with an on-board receiver to provide precise elevation information and control.

For more complex projects - establishing a super-elevation for a roadway, for instance - motor graders and crawler dozers can use Cat AccuGrade GPS (Global Positioning System) or UTS (Universal Tracking System) technology. The machine combines three-dimensional positioning information - from satellites (GPS) or from an on-site robotic total station (UTS) - with data in an on-board digital terrain map to automatically adjust its blade for precise control.

Hydraulic excavators, likewise, can use AccuGrade systems ranging from machine-mounted sensors, to laser systems, to GPS/UTS systems. A recent study at the Technical University of Reykjavik (Iceland) showed that a Cat 330D, equipped with an AccuGrade GPS System, met the design criteria for a complex trench excavation 24 percent faster, using 22 percent less fuel, compared with a 330D under manual control.

Biography

Dwight J Roberts is a Connected Worksite Product Application Specialist for Caterpillar, Inc. Roberts' recent job experiences include helping customers in Asia be successful by utilising Caterpillar machines with connected worksite technologies, such as AccuGrade and Product Link. Roberts holds an engineering and Masters of Business Administration degree from the University of Illinois and Bradley University, respectively.