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It
may seem like 25th century stuff, but computer-aided or controlled site
work is already serving notice that it will become a way of life in
grading and excavation work 500 years before Buck Rogers is due to be
born. Here's a look at where we are and where we're going.
By
John Trotti
Moving
Mountains Caterpillar Style
Making the Grade at the Morenci Mine
El Dorado Hills Development Project
Putting the Laser to Work
Bring Science to Art
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.
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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.
The
CAES-equipped tractor uses displays similar to those in
the space shuttle.
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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.

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Making
the Grade at Morenci Mine
Jody
Crum of Phelps Dodge's Morenci Mine puts CAES to work in
haul-road and bench construction. Doin so has caused his
skills to increase dramatically.
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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.
The
accuracy of the CAES-equipped D11 is such that productivity
has jumped significantly for many users.
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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."

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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.
"SiteVision
will change the way we move dirt and, more importantly, how we
will be able to bid dirt work"
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."

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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.

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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.
Moving
in tandem, two Komatsu PC300LC-6 excavators met the production
schedule of 2, 000 - 2,500 cu. yd./day.
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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."
The
Milwaukee Art Museum is scheduled to open on December 31, 1999.

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