The demand for increased productivity continues to be driven by the high costs of manpower and equipment, but other factors loom larger on the horizon. One of these is the impact that access to information via the Internet is having on our ability to make cost/performance comparisons as part of the bidding process, which in turn accelerates the demand for the right people having the right information at the right time. It’s little wonder that more and more contractors are looking to technology—particularly those featuring graphic display—for answers in meeting the challenge. Because of their growing acceptance in specialized applications and their promise for the future, we intend to focus attention on emerging technologies that address productivity. We start here with computer-aided and/or controlled site-work systems such as Caterpillar‘s Computer Aided Earthmoving System (CAES), Trimble‘s SiteVision system, Spectra Precision‘s BladePro Motorgrader Control System, and Topcon‘s Touch Series Five automatic slope- and depth-control laser system.
Moving Mountains Catepillar Style
CAES, to date the most advanced site-work system, uses onboard computers, software, global positioning systems (GPS), and data radios and receivers to replace conventional surveying and site-mapping techniques. The system accepts plans generated with conventional computer-aided-design software. As installed at Phelps Dodge’s mine in Morenci, AZ, Caterpillar’s Mining and Earthmoving Technology Systems (METS) software, called METSmanager, translates plans into CAES format, transmitting information in the form of a two-dimension terrain model to a CAES-configured machine via a high-speed radio system developed jointly by Trimble and Caterpillar. Terrain updates are collected and transmitted back to the office where METSmanager feeds the data to the CAESoffice program, which combines terrain updates from all machines working in the field to maintain a single up-to-date model of the site. Such data provide immediate, accurate production calculations, allowing supervisors to make operating decisions based on accurate, real-time information.
CAES allows managers and engineers to integrate the various planning and design functions of a project and then graphically display real-time data to equipment operators to help them achieve higher production rates. By delivering a color-coded site-plan display showing how much material must be cut or filled and the location of the machine in relation to the site plan, CAES gives operators with “howgozit” information as well as with current topography and cross-sections, which are updated as the surface is altered. Such graphic detail eliminates the requirement for placing—and constantly replacing—the hundreds of survey flags normally used to define elevation, grade, slope, and material type at the job site. Similarly, CAES addresses problems of low visibility because operators are not dependent on sighting flags or other landmarks. Designed to work with many different types of equipment, systems are available for front shovels, wheel loaders, track-type tractors, scrapers, motor graders, and compactors. The display for each type of machine is slightly different, but only the onboard software differs between machines.
METScomms, a Windows-based component responsible for radio communications, file conversions, and site-terrain data manipulation, is the heart of the METS office software suite.
Making the Grade at Morenci Mine
Phelps Dodge Morenci Inc. is the largest copper producing operation in North America. Operations include an open-pit mine, two concentrators, and two solution extraction/electrowinning (SX/EW) facilities. In 1997, Morenci produced a record 1.1 billion lb. of copper, including 550 million lb. from SX/EW. The operation began construction of an $81-million expansion that will use low-cost SX/EW technology to reduce overall operating costs and increase annual production of copper by 50 million lb. In order to increase productivity and reduce transport delays, in 1995 Phelps Dodge began installation of CAES along with Caterpillar’s METS, which provides a real-time information link between the mine offices and machines equipped with CAES to give operators access to current mine plans within minutes of their creation. Similarly, office personnel have access to a current digital terrain model (DTM) of the mine site as it is updated. The marching orders were “Make it work.”
While Phelps Dodge’s primary interest in the use of CAES/METS has to do with mine-face activities, the system has become a valuable tool in bench and haul road design, and construction as well. With the system installed on the three Caterpillar D11Ns dedicated to road maintenance, the Engineering Survey Department is geared to meet all challenges. “There are more than 35 miles of active haul roads at the mine, so we try to schedule work six months in advance,” explains the department’s technical coordinator, Brian Ford. Even such major engineering tasks as the recent change from a right-hand to a left-hand traffic pattern on the site can be accomplished without as many headaches as would have been the case in the past. “The key to our success is getting it right the first time,” Ford states. With the control and project visibility afforded by CAES, the outcome of such a project is a lot more predictable.
When it’s time for the construction of new bench, the project is designed on a standard CAD workstation using AutoCAD Terra Model and then fed into METSmanager for conversion to CAES-readable code and subsequent transmission to the piece of equipment designated to perform the task. That’s when Jody Crum or one of the other D11 drivers gets to work. “We had three months to work out the bugs,” Crum recalls. “At first we were concerned by the idea of having ‘Big Brother’ watching over our shoulders, but it turns out that there was nothing to worry about.” In fact, the people who needed to be concerned were those who enjoyed placing stakes and checking grades, because those parts of the job disappeared almost immediately.
With the flat-plane and inclined-plane display features, the operator knows where he is at all times, what needs to be done, and what it takes to produce the desired grade. “A bench requires about 100 feet of run-in,” Crum explains. “With the system, I can get the job done right the first time without having to worry about finding or running over the stakes. According to surveyor Andy Obregon, the accuracy of the CAES-equipped D11 is plus or minus 6 in.—“an incredible improvement. Our productivity has increased 70 percent since we got the system.”
How long does it take a new operator to become proficient with the system? “It’s a matter of a few days to get used to the displays and believe in them,” says Crum. And while it can make an inexperienced operator look good, it’s the considered opinion of all the CAES operators that the real gains come from the “old hands” whose skills are increased dramatically by the system. Or in Crum’s words, “CAES toned my skills.”
El Dorado Hills Development Project
Kiewit Pacific in Concord, CA, is constructing a large residential development near the community of El Dorado Hills, east of Sacramento. The project comprises of 300-some-odd house pads, large slopes, and approximately 8 mi. of residential streets and cul-de-sacs, and it entails nearly 2.8 million cu. yd. of earthwork. Soil condition is extremely rocky, requiring heavy ripping of the sedimentary rock material along with extensive drilling and blasting. For a feel of the project’s scale, consider that Kiewit is using about 400,000 gal. of water per day to control dust and achieve compaction of the fill areas.In order to accomplish the task in the most cost-efficient manner, Kiewit has turned to GPS technology utilizing a fixed base station that communicates with the D9N dozer via a high-speed radio modem to achieve centimeter-scale accuracy in X, Y, and Z axes. The machine-mounted components include a Trimble MS860 GPS receiver, an SV170 color computer, a Trimcomm 900M high-speed radio modem, Trimble L1/L2 GPS antennas, and programmable light bars to guide the operator to grade. Collectively, these components comprise a grade-control package Trimble calls SiteVision GPS Dozer, which Kiewit agreed to beta-test for Trimble.
“Our goal was to prove the software and hardware package in a real-world environment,” says Trimble Project Manager Jon Casamajor. “An added personal goal was to put the system to a very harsh mechanical challenge to determine what failures were likely under extreme conditions. We managed to uncover a few problems, but the system has performed extremely well after a month of very harsh conditions. The D9 itself has had a few mechanical problems, but the SiteVision package has had very few and nothing major. SiteVision is used to guide the D9N to finish grade on slopes and building pads with minimal or no staking, grade checking, and layout,” Casamajor explains.
Kiewit elected to go with the system to learn what will be required internally to embrace the new technology. Expectations were that it would allow the finish dozer to work more productively and consistently and without the delay of waiting for grade stakes. The results have proved the thesis far in excess of original expectations.
“Under optimum conditions—when we can get rid of the cut material efficiently—we’ve been able to dramatically increase production of the machine, and the operator is able to work alone and without a grade checker,” reports Brian Smith, general superintendent at Kiewit. “The finish foreman is able to spend his time in other productive areas while the operator of the dozer produces finished pads and slopes. In addition, the operator is able to find and build both tops and toes of slopes, which can be staking nightmares, and more efficiently move the excess material for removal by the scrapers.”
Bob Alto, who has been driving dozers for 24 years (the past 14 for Kiewit), explains that his cab’s digital plan displays the geometry of the pads, the roads, the lot dimensions and slope locations, and an icon representing the machine relative to those structures on an easy-to-view color display. As a result, he can navigate to any point on the plan and determine on the fly what needs to be done—cuts and fills—to reach the design in all three axes. “I’ve never felt so in control of productivity and the quality of my work,” Alto says. “I’m having a ball with the system!”
“SiteVision will change the way we move dirt and, more importantly, how we will be able to bid dirt work,” states Bo Diaz, Kiewit superintendent. Casamajor agrees: “This product will revolutionize this type of operation. It’s biggest impact will initially be with the larger jobs where the largest risk is always a reality. The margin of error on this type of job is quite small, and small mistakes can turn the ink from black to red in a short time. As Trimble enhances this initial product and adds new features to the basic SiteVision product, the dirt contractor will have a series of new tools that will change the industry forever.”
Putting the Laser to Work
Laser technology is used to spread a harmless, stable plane of laser light over a job site to provide an accurate reference for achieving a flat or even a sloped work site. Spectra Precision’s Total Station allows an operator and prism holder to quickly calculate a broad catalog of details, such as the height of remote objects, the distance between two points, and the coordinates of various site locations for help in staking and engineering complex work sites. The system’s Laserplane transmitters send a continuous, self-leveled reference plane over sites up to 2,000 ft. in diameter to provide information for setting, adjusting, and marking elevations, as well as controlling excavation cutting depths. Mounting a laser receiver on equipment establishes a benchmark on the machine, allowing the operator to control grading from the cab of the machine.The BladePro Motorgrader Control System is a dual automatic blade control using advance computer technology and intuitive operator controls that provide the operator with information to grade with consistent accuracy at high operating speeds. The system using the company’s Tracer Ultra Sonic Grade Controller or Laserplane transmitter receiver system to accomplish a variety of earthworking tasks. Applications for the BladePro include highway and residential roads and commercial and residential developments. Additionally, it can be used for motorgraders, dozers, mills, and trimmers.
Bring Science to Art
In 2000, the downtown Milwaukee skyline will be enhanced with a dramatic $50-million addition to the Milwaukee Art Museum. While the December 10, 1997, groundbreaking for this addition brought out all the usual dignitaries, the initial construction phases have been underway with far less fanfare, yet with no less importance.
Schneider Excavating, headquartered in Lannon, WI, is a commercial-site developer with an impressive resume of projects in the city of Milwaukee and is spearheading the effort. Schneider Excavating’s contract for the expansion included the mass excavation of more than 70,000 cu. yd. of dirt, installing a dewatering system, installing a drain tile system for the underdrain, and backfilling with structural fill around the perimeter of the building. Although Steve Ristow, the company’s owner and president, says the project has posed several different challenges, perhaps the biggest was during the excavation. “It was somewhat challenging to say the least,” remarks Ristow. “There were dewatering problems. It was also necessary to separate the excavated soils because some were contaminated, some were to remain on-site, and some were to be trucked off-site. So our excavator operators had to segregate the soils as we were excavating them. That can be tedious. You have to be more attentive to what you’re doing than just bulking out dirt.”
With the segregation of soils creating an extra burden, Ristow calculated that in order to complete the mass excavation on time, he would need to employ both of his Komatsu PC300LC-6 hydraulic excavators. “We knew that one PC300 wasn’t going to be adequate, so we calculated that in order to meet our schedule of between 2,000 and 2,500 cubic yards of production per day, we were going to need two PC300s running.”
Schneider Excavating’s excavators have been outfitted with a couple of modifications that help enhance their productivity, according to Ristow. “We have our PC300s equipped with Hendrix quick couplers so changing attachments is controlled from the cab. Before we had to take maybe a half-hour to switch a bucket. Now, right from the cab, the operator just flips a little button that untoggles a latch, unclips one bucket, and clips in another within one minute. He never leaves the cab, and he has a new attachment on it.”
Ristow also equipped the PC300LC-6s with the Topcon Touch Series Five automatic slope- and depth-control laser system—the first Komatsu excavators in the world with that system. The system automatically links several sensors to a hydraulic valve control box and an operator’s control panel to automatically control depth and slope of a cut. The control is achieved by making precise automatic adjustments in both the tilt of the bucket and the up and down movement of the boom.
Quality control and increased production is how Ristow summarizes the benefits of the Topcon system. “It gives you a better job at the end. If you’ve got a highly qualified operator and you put him in a computer-aided machine like our Komatsu PC300LC-6, there’s almost nothing he can’t do well. In fact, Mike Bremberger, one of the PC300LC-6 operators, earned a quality improvement award from the Milwaukee Art Museum Building Committee for the work he has done on this project.”
Even though Schneider Excavating earned the museum site development contract because of its low bid, Ristow, owner and president, says that its reputation for quality work certainly didn’t hurt. “We’ve always been known as a trucking company. Mass excavation is one of our fortes. It’s something that a lot of people would say is a Schneider job.”Ristow says this reputation has also been built around good employees. “We’ve always looked at the successes of this company as a team,” says Ristow. “It’s not just me—everybody else does their job so well that it lets me kind of watch what’s happening. I have some very key people who help me here. Our employees represent the company, and we value them a great deal. The reason we get lots of work is because people like working with us. It’s about customer satisfaction. If you don’t care for your customers, someone else will.”