Behind The Scenes With 3-D Controls

Last month, contractors shared their experiences with automated grade control systems on actual jobsites (“Automated 3-D Controls Shave Time,” December 2004). However, before the equipment starts to move ground, electronic models must be created to provide the hardware with the proper cut and fill information.

This month, these contractors and suppliers of automated 3-D grade control systems share their experiences with the software and electronic files that drive them. Dealing with electronic data is a new concept to some contractors and it requires a different approach.

But don’t let the software and electronic files become a deterrent to implementation of automated grade control systems. “The technology is great,” says Allen Steele at Allen Steele Co., a Lake Delton, WI, contractor that performs sewer and water work, as well as dirt work.

Allen Steele Co. purchased an automated grade control system from Leica Geosystems in order to increase the speed and efficiency of achieving the finish subgrade in preparation for gravel on roads. “I don’t think you have to be nervous about the technology,” says Steele.

The outsourcing option

Allen Steele Co. outsources the building of the necessary electronic files and data preparation. “We are using a local engineering firm. We have had a lot of good luck,” says Steele.

This is a common solution that simplifies implementation of automated grade control systems. “A lot of it is being outsourced,” says Fred Rogers, Leica Geosystems.

In addition, many of the system suppliers have resources available to solve technical problems with the electronic models. For example, Leica Geosystems has an in-house service that troubleshoots models for contractors. If a contractor has problems with a model and the person that contractor hired can’t locate the source, Leica’s in-house service will help find the errors.

Outsourcing the electronic models streamlines the learning curve. Jim Martin, site prep manager, Crossland Construction, reports that handling the electronic files is relatively simple. Crossland Construction is a 25-year-old Columbus, KS-based site development contractor. Its Topcon dealer — Ozark Laser and Shoring in Springfield, MO — helped hook the contractor up with a consultant, Take-off Professionals, for surface file preparation.

“We don’t create our own maps,” says Martin. “We farm that out. We get our file from our guy who builds the model. It is just a matter of somebody being able to run a computer to receive the e-mail and download that onto the card that goes into the machine, which is very simple.

“You slide in the diskette, then tell it to copy. You give it a name and a description. All of it goes on that card,” he explains. “As you change from job to job, the only thing you have to remember is you have to change the file to match the job you are on.”

Assign a point person

Implementation of this technology requires you to develop a process for handling electronic files. “When we are talking 3-D systems, it is usually best to have a point person in the office who is in charge of the files,” says Bob Highfill, Topcon. “It is usually someone with engineering experience who takes and converts the files.”

Don’t be intimidated by the electronic files. “It is an obstacle if you let it be,” says Highfill. “When I do a seminar and teach someone the basics of GPS, the file thing is a gray area — and it’s usually a scary area. We separate the model building from the management of the finished files. That way, we can focus on different parts of the process important to that particular person.”

Highfill first concentrates on introducing the contractor to the basics of GPS. “I actually get that first file created for them,” he notes. Then they are trained on how to use the equipment. “They see their production costs go down and they see what GPS actually does for them.”

Next, Highfill locates someone in the office who will be in charge of the files. This person is instructed on how to create a file.

Highfill cautions not to overwhelm your foremen and superintendents with the technical jargon. “If you were to go out and talk about transferring .dxf or .dwg files to the foremen or superintendent on the job, they don’t understand,” he points out. “That changes once they find out the job file is just part of the process.

It’s the information they need in order to know where they are at all day long.”

In-house modeling

Building your own models in house also has advantages, including the ability to catch problems with the drawings prior to starting the job, as well as control over accuracy of the models.

“We are developing our own models,” says Kenny Liesfeld, J.E. Liesfeld, a site development and road construction contractor that uses 3-D grade control from Leica Geosystems. This requires in-house expertise. “We already had somebody in house that had some engineering and AutoCAD experience. With that experience, he was able to create models. He is still learning, but he picked up on it pretty quickly.”

Another benefit is that while you are creating electronic models, you catch a lot of the problems on the drawings. “It is almost guaranteed that you will find a problem with the drawing once you get started,” says Liesfeld. During the process of creating the electronic model, it is run through a simulator. “For the most part, we catch the majority of the problems before they are even sent to the machines.”

SCI (Steven Counts Inc.) is a site development and roadbuilding contractor with 248 employees and over 200 pieces of yellow iron. It has been using Topcon GPS equipment for a little over two years. The company makes its own maps and takes full advantage of the GPS technology.

“Obviously, with the new technology, trying to get people who are already in the industry to understand and gain confidence in the fact that this does work — that’s always a hurdle you have to face,” says Chuck Counts.

But SCI has embraced the technology. “We are a young company,” says Counts. “Steve [the owner] instills in everyone here that we are going to use technology to our advantage.”

Design files developed by the draftsmen and survey techs in the office provide several advantages beyond machine control. “We have one supervisor’s package where the supervisor of a particular job has a hand-held unit in his truck,” says Counts. He can ride around and see real-time elevations and cut and fill information based on the design files used for the machine control.

“We utilize GPS not only in localizing the sites for GPS machine control, which you have to do, but also for layout and topographic surveys either prior to bidding the job — just to verify the engineers’ topo — or during construction to track quantities. Then at the end we do as-builts,” Counts explains.

Paul Reed Construction is a Scottsbluff, NE-based general contractor that performs everything from residential to light industrial work. It has used Trimble GPS with automated machine controls for the past three years.

“There have been quite a few upgrades in the last three years,” says Ben Ryschon at Paul Reed. “They just keep improving it every year.”

Paul Reed Construction uses Trimble Terramodel software to convert design files into models for the automated machines. Terramodel software is designed for the surveyor, civil engineer and contractor who requires a CAD and design package with integrated support for raw survey data.

“If you are just doing simple site work for commercial building pads, parking lots or small streets, you can get by with limited knowledge of Terramodel,” says Ryschon. “When you buy the product, they come out and give you three days [of training]. In those three days, if a person has any CAD knowledge, he can grab onto it and really run with it. Like anything, the more you work with it, the more proficient you are going to become. I only had three days of training when we bought the equipment, but I am a surveyor/civil engineer tech. I went to school for this.”

Ryschon praises the compatibility of Terramodel with AutoCAD files received from outside engineering firms. “Whenever we get a job, typically there is always an engineer who designs that job,” he notes. The electronic files the engineers create when designing the project are then shared with Paul Reed Construction. “That’s the beauty of Terramodel — it will take whatever format the engineer designed the project in and allow you to work in your own format.

“We have been real fortunate,” Ryschon adds. “Every job we ever bid on, except for one, we have been able to get the AutoCAD design files. Then we just dump them into Terramodel. We pick the layer we need, like the finish grade layer, and we create out cards off of that.”

So there are several options for dealing with the electronic files necessary to run automated grade control systems. Depending on your comfort level with the software technology and the resources at your disposal, outsourcing or creating in-house models are both valid solutions.

Controversy Over Electronic Data Access

Most of the time, design firms are willing to share their electronic data with contractors building the project. However, dealing with electronic data still poses a hurdle to some contractors, says Fred Rogers, Leica Geosystems. Many contractors face a challenge acquiring the digital data necessary to build these models from the engineering firm.

According to Ben Ryschon, Paul Reed Construction has run into such a problem. One excuse has been due to insurance concerns. “They say that they are liable,” he notes.

But does it really make a difference if there was a mistake in the electronic data, or if it was on a printed set of plans? “You are still responsible to build a job as per planned on paper,” says Ryschon. “In the end, it is my responsibility to make the job come out as planned.”

If the design firm is unwilling to share the electronic data, that doesn’t mean you can’t create your own electronic models. “Most companies will give you coordinates for your control points,” says Ryschon. “I can do my site calibration and basically go back in and build the job in [the Trimble] Terramodel right off of the plan. Basically, it is doing what they have already done.”

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