Factory-Installed System Simplifies Grading

By Katie Weiler, Managing Editor | September 28, 2010

In late November, Caterpillar demonstrated the difference between operating a new D3G track-type tractor manually versus operating a new D5G with the AccuGrade Laser Grade Control System—the first factory-installed laser system in the industry. Experiencing that difference first-hand, I can confirm that even a novice operator will be able to fine grade with accuracy thanks to advanced laser technology.

The AccuGrade system is designed to allow dozer operators to bring an area to grade faster and with fewer passes. In fact, says Cat, the resulting increases in productivity and accuracy—as much as 50 percent—are accomplished without using traditional stakes or grade checkers. The new system is aimed at fine-grading applications and can provide flat, single-slope or dual-slope surfaces within a tolerance of 0.24 inch. Plus, factory installation means owners can use their Cat dealer for ordering and servicing.

How does it all work? Here is Caterpillar's explanation: The system has laser receivers mounted on the blade that automatically control the machine's hydraulic system. A thin beam of light from an off-board laser transmitter provides precise elevation information that is picked up by the receivers. In turn, the blade's lift and tilt are automatically adjusted as the machine moves over the area.

Operators can select either automatic or manual operating modes. An in-cab display provides a simple view of all system information, and a beeper and colored lights indicate the blade's position relative to desired grade. And don't be surprised if you find this technology on larger Cat track-type tractors and motor graders later next year.

Of course, AccuGrade is just one of many improvements made to the new G-Series tractors. Another important feature is the new EPA Tier 2 and CE Stage II emissions-certified engines. Cat's 3046 six-cylinder diesel is now turbocharged for improved responsiveness on all three models. The D5G produces 90 horsepower at the flywheel, and the D4G and D3G offer 80 and 70 horsepower, respectively.

Additional standard equipment includes two heavy-duty, 12-volt 900 CCA batteries; a turbine-type precleaner; a 110-amp alternator; an air intake heater for easier cold-weather starting; and a comfort-adjustable suspension seat.

The G-Series features a hydrostatic drive train, which provides greater control, ability to work in tighter areas, more power during turns, and counter-rotation of the tracks. The tractors—made of a solid, one-piece mainframe derived from larger machines—also have an exclusive rotating bushing track to eliminate pin and bushing turns and increase durability.

Two undercarriage configurations are offered—the XL with extended length roller frame, and the LGP (low ground pressure). All models come equipped with a variable pitch, power angle and tilt (VPAT) blade. The blades have been upgraded with a 13- to 15-percent increase in capacity, larger blade trunnion, four-piece cutting edge, and improved grease-fitting access to simplify serviceability.

Estimated list prices range from $75,000 to $117,000 for the G-Series. The fully automatic, dual lift and tilt AccuGrade option is estimated at $24,500 list price. 

Basic Specifications: G-Series XL Models
Operating weight 16,227 lb. 17,196 lb. 19,630 lb.
Track Gauge 57 in. 59 in. 61 in.
Track on Ground 81 in. 87 in. 91 in.
Ground Pressure 6.23 psi 5.47 psi 5.36 psi
Blade capacity 1.88 cu.yd. 2.41 cu.yd. 2.86 cu.yd.