Hemisphere GPS 2010November 2010
EXCAVATION WITH EARTHWORKS X200
Large contractors handling big projects are not the only ones who want to save time and money by using machine control guidance systems. Smaller contractors want to see those savings, too.
Prattco Excavating, a mid-size contractor based in Calgary, Alberta, Canada, with about 40 employees, focuses its business on residential basement excavation and light commercial site preparation. The company wanted to find a way to reduce operating costs and save time during basement excavation.
Prattco’s vision to increase productivity led them to purchase a Hemisphere GPS Earthworks X200 guidance system. The company considered other GNSS guidance systems but found that they were too complex, expensive, and did not provide operators with full 2D guidance.
Hemisphere GPS took less than a day to install the Earthworks X200 system on Prattco’s John Deere 200D LC excavator. Through the use of precise tilt sensors, a laser catcher, and Crescent Vector GPS technology, the X200 system provides the operator with a true 2D grade control guidance system. Controller Area Network-based angle sensors mounted on the boom, stick and bucket integrate with a 5.5-inch touch screen terminal, giving operators real-time accuracies of 2 centimeters to the bucket teeth.
The system also features a Crescent Vector GPS Compass mounted on top of the excavator, which sends true rotational angle measurements to the terminal in the cab unlike many other systems which use proximity switches to measure slew angle.
Though the Prattco excavator operator had more than 30 years of experience with heavy equipment, he had not used a GPS guidance system before. Hemisphere GPS sent a technical support representative to train operator Eugene Bleau right on-site while he continued to work on regular projects. This helped eliminate excavator downtime as the operator was learning the X200 system and working at the same time. Quick reference guides and software also helped the operator to learn the new system.
In less than 2 days, Bleau was comfortable using the system for basic jobs such as flat plane, single slope, and dual slope configurations. In less than 1 week, he was beginning to use the system for more advanced dig modes such as custom profile and custom trench.
“The breadth of information and job methodologies now available to me in the cab is tremendous,” says Bleau.
With the Hemisphere GPS Earthworks X200 system, Bleau could view the position of the bucket, relative to desired grade, on the in-cab color touch screen. Using the X200 stick angle sensor with an integrated laser catcher, he entered the bench height of his rotating laser and positioned the laser catcher to read the laser signal. This established a known vertical reference height usable regardless of where the excavator tracks on-site.
Next, Bleau entered the desired depths of the various grades that make up the basement and started digging. Initially, he frequently checked the depth manually using the rotating laser and a level rod but soon found this to be unnecessary. Eliminating the regular out-of-cab grade checks allowed him to move more dirt in less time, reduce machine idling hours and remain safe within the cab.
The X200 made it easy for Bleau to change his bucket type to fit soil conditions. Since Bleau premeasured the bucket sizes and stored them in the X200 system, he maintained constant digging accuracy after changing his bucket by selecting the new bucket from the list saved on the X200. This made the basement excavation truer to grade and survey.
“My company purchased two Hemisphere GPS X200 excavator guidance systems in late fall 2009, and we have proven them to increase productivity and impact the bottom line by more than 25 percent,” says Doug Pratt, president of Prattco Excavating.
Even on small construction projects such as basement excavation, time savings from machine control multiply daily, weekly, and annually. On average, owners report the X200 system pays for itself in less than 3 months. Not only does the system provide gains in efficiency, but it also enhances the performance of digging to grade. The grade levels are more consistent and rework is basically eliminated. ■
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