“There are two great benefits,” he says. “One is you don't have to have a surveyor. The second is you can go anywhere on the project, at any given time, and you know where you're at. You know your grade; you know your alignment.”
This has become key to Cox at least keeping his proverbial head above the water at work on the sports complex, comprised of eight baseball or softball fields, five soccer pitches and four parking areas.
“There's not a field out there that is the same elevation — every one of them is different,” says Cox. “And they've got four of the ball fields back to back, and there's not one of those that is the same either.”
Once the site info is loaded into the control box of each machine and into the survey rover, it's job-on for contractors like Cox, notes Dow. “On a daily basis, he'd set up his base station, which takes all of about five minutes, maybe less, and he can begin moving dirt. And his guys are going to know at all times precisely where they are relative to grade.
“In the past, Larry would have been dependent upon a surveyor to stake his job,” says Dow, vice president of Trench Safety, based in Memphis, Tenn., with a location also in North Little Rock, Ark. “And he couldn't really start work until that surveyor staked the job. So, we would have had the hurdle of, 'How quickly is that surveyor going to be able to get to my job? How quickly is he going to be able to stake it to the point that I can start moving dirt?'
“Once the job was underway, he would have been very dependent upon his operators, and it would in essence be simply eyeballing as those guys moved dirt. In many instances, he would have even had to have assigned a grade checker to each piece of equipment to walk along the machine constantly checking, constantly communicating to the operator: You know, 'You're high; you're low; no, no, no, that's too much; no, you didn't move enough.' It would have been a trial-and-error process, very laborious, not very exact . . . pretty crude in retrospect.”
Indeed, while the conditions around he and his crew may, thanks to the weather, be crude, the manner in which they work is no longer, says Cox.
“When you're looking at that control box, it tells you everything that a surveyor used to put on stakes,” says Cox, who knows full well what all the rain would have meant otherwise. “If you're staking it, a lot of times the marks rub off the stakes or the rain will get it where you can't read it. You don't lose anything with the machine control.”
Developed by the job's contractor itself or an outside engineering/surveying firm, the DTM resembles a wire mesh model, detailing the elevations throughout the site. It incorporates data compiled from the job's computerized design and modeling constructed via such popular software as AutoCAD and AgTech.
“In some cases, the DTM can actually be created within that software,” says Dow. “In other instances, you will export a point file, and then import that point file into a program like Topcon's Office 3D, where you'll actually create the DTM.”
Out in the field, the contractor uploads the DTM into a control box on his assorted GPS equipment. “Typically, today it would be via a compact flash card,” says Dow. “The operating system inside the control box recognizes that compact flash card, and you can copy or import that file into the control box and it's going to provide that detailed positional information.
“The GPS system will know the precise position of the left and right corners of the cutting edge and, in real time, the control box will compare that information with the DTM and will show it on the screen. For example: The left corner of the blade is a foot high; the right corner is a foot low. The operator will have that information on the screen. He'll also have the option of sending that information to the hydraulic systems of the grader or dozer and moving into auto mode. At that point, the operator's primary role is just driving the machine, with the control box controlling the hydraulics and, in turn, the position of the blade.”
Without 3D, says Cox back in Heber Springs, “we'd be so far behind we couldn't even see daylight. You'd have had to go out and set hubs and grade stakes probably two or three times on each field.
“It's pretty tough, especially when you're dealing with a complex job like this one out here. We would have to have probably four or five laborers just running stakes for the grader. If we had done it the old way, we'd have to have two, maybe three motor graders out there running also.”
Conversely, with 3D, an element of job proprietorship was put back into Cox's hands. “The main thing was being able to have the control — not having to have somebody to help you set grade — and it's so much faster,” he says. “You don't have to have anybody on the ground running hubs, uncovering hubs, or anything like that.”
The response of contractors like Cox to 3D “has almost been universal,” says Dow. “Once these guys get this technology and they realize what it does for them, they're like children in a candy store. It just changes everything: It makes them so much more productive; it makes them so much more precise; they get finished with their projects so much quicker.
“And a great example is Larry. This was a huge expenditure for his company, and he very quickly saw the benefits to the point that he could justify in his mind spending additional money,” says Dow. “Almost every contractor that we've dealt with on this equipment has started small. They might buy a survey rover and a base station, and a system for a motor grader or a dozer, and then fairly quickly they come back saying, 'We need to put systems on additional pieces of equipment.'
“The usage of this equipment is becoming sufficiently widespread that these guys realize they can't be competitive without it.”
In Heber Springs, who knows if the rains of 2007 will be remembered in the decades to come? It won't matter anyway, says Dow.
“For that community, this project is big: It's big in terms of the dollars; it's big in terms of just the physical size; it's big in the sense that — and I think this is pretty neat — it's going to become the focus of a lot of families in that part of Arkansas,” he says. “This is going to be a real focal point for the community. The kids will be playing on these ball fields in 30 and 40 years.”
For the contractor trying to level those fields today, the future is likewise clear — thanks to 3D.
“Today, you couldn't drag that equipment out of their hands,” says Dow. “If you said, 'Larry, I'm picking it all up right now,' he'd looked at you and in no uncertain terms tell you that you weren't walking off with his equipment — that he just had to have that equipment.
“It just literally changes the way people move dirt.”