Trimble’s SCS900 Site Controller System

Imagine a tool you could haul around in the field by yourself that instantly checks topos for accuracy, calculates the volume of dirt in a stockpile, or measures the flatness of your building pads.

Such a tool became a reality with the introduction of the Trimble SCS900 Site Controller System. The device consists of a small computer tethered to a GPS* receiver mounted on a pole, or attached to a truck or utility vehicle. Small as it seems, the computer contains enough memory and processing power to store 3-D site plans and all the data for numerous jobs. With the GPS information it receives from satellites, the computer creates instant updates on the site’s topography – the same sort of information that would take a survey crew hours to shoot and compute.

McAninch Corporation of Des Moines, Iowa, has been a leader in GPS earthmoving technology, and obtained three SCS900 Site Controller Systems last fall. “The way it worked before, our foremen would call us and say, ‘Hey come shoot this. I want to know how much dirt or fill I have left,'” says Tim Tometich, GPS manager at McAninch. “Then we’d have to send survey crews out, bring it back into the office and run it through three different software programs to get the answer. With the SCS900, the foreman on the site can do it himself in about five minutes.”

Establishing the costs of change orders and the extent of unanticipated problems is another feature Tometich thinks will come in handy. “If we have a building excavation and discover soft or unsuitable soils that have to be removed, we can shoot it before and after and compare the quantity, or compare it to the design surfaces already loaded into the system,” he says.

Set up around work orders
“Everything is oriented around a work order system,” says Chris Mazur, a GPS specialist for Ziegler Cat in Des Moines. The digital drawings and all pertinent information to complete the task are transferred to the SCS900 field controller. “Whatever you want the foreman to do, you set up as a work order. When that person gets out into the field all he has to do is turn the unit on and go to work,” he says.

Armed with an SCS900 the foreman can leave the office or construction trailer in the morning with all the information he needs to manage multiple jobs, says Kurt Maynard, Trimble construction segment manager. “He can have totally different situations all on the same card, do all the tasks and check them off as he does them. It used to be that you had to dump all that information into one file and come back and sort it all out.” When the foreman returns to the office now, he synchronizes with the office computer – depositing all the completed work orders and retrieving new tasks with associated data automatically.

Not much bigger than a PDA, the computer on the SCS900 holds numerous site drawings, work orders and historical data for projects.

Boosting the productivity of foremen
Matt Dykstra, a surveyor for McAninch, helped evaluate the SCS900 and train three of the company’s foremen on the new devices. What allowed them to accept the new technology quickly, he says, was the intuitive screen interface and the fact that GPS gives foremen the ability to perform certain surveying tasks without any formal training in survey work.

Accurate record keeping is also a plus. “If a user bypassed a procedure in the field, the SCS900 will have a record of it and we can access the problem easier,” Dykstra says.

Where stakeless GPS grading is being used, the SCS900’s record-keeping abilities also serve as a quality control measure. “If another contractor comes in and tears up your site, there’s usually a lot of finger pointing,” says Tometich. “Without paying a surveyor to resurvey the ground, there’s no telling who is responsible for what.” With the SCS900 you can plant your pole, push a few buttons and show the exact topography of that spot now vs. the last time you checked it.

Changing skills and roles
As with other GPS earthmoving technology, the SCS900 requires contractors to rethink their workflow and their company skill sets to get the most out of it.

A lot of the post-survey CAD/computer work that used to fall to Tometich is eliminated with the SCS900, freeing up more time for bids and project management. Foremen who used to wait on surveyors will suddenly find their schedules accelerated. And having a person with a surveyor’s background like Dykstra helps in training foremen and in serving as a liaison between the office and the field.

Some surveyors view GPS systems as a threat, Dykstra says. And while systems like the SCS900 reduce the need for survey work, GPS systems are here to stay and are only going to get more intuitive. The way for surveying professionals to remain relevant in the face of this technology, says Dykstra, it to embrace it as one of several tools in their skill set and use their knowledge of surveying to help construction contractors get the most value from their GPS systems.

Bang for the buck
Although McAninch had an extensive GPS program before it started using the SCS900, prior GPS experience is not a prerequisite. The SCS900 can also be used as an entry-level device for contractors who want to start dabbling in GPS technology, but aren’t ready to wire their machines with a full-bore GPS guidance system.