What is the value of a pile of crushed stone, sand or gravel? Gathering this information hasn’t traditionally been an exact science. A percentage of material is lost every time a load is sold, but capturing precise volume data on an ongoing basis has been practically impossible due to the costs and hazards of stockpile surveying. As a result, companies often lose millions of dollars each year due to inaccurate volume calculations.

David Dossey, RPLS, and Aaron McMillan have a history in concrete products and manufacturing, and the contacts they developed in that business gave them a solid understanding of the issues encountered by companies in the aggregates industry. Ten years ago, they began 1519 Surveying, LLC in Waco, Texas, and have used Leica Geosystems solutions to perform stockpile surveys, as well as surveys for oil and gas, engineering and real estate.

Dossey and McMillan upgraded an older model Leica Geosystems robotic total station to the Leica Nova MS50 MultiStation, which combines fast, high-precision robotic total station technology with 3D laser scanning, digital imagery and GNSS connectivity. They immediately saw they would be able to improve their services to the aggregates industry. “There’s a constant need to inventory the raw material,” McMillan says. “We used to do it every quarter with traditional survey methods, but we saw that we could provide a better solution with long-range laser scanning capabilities.”


Creating a Plan of Action

Dossey and McMillan’s company secured a project and coordinated a schedule for their scanning technician, Daniel Cogburn, to visit nine of the client’s remote sites. Cogburn planned to perform the fieldwork with a high level manager present to witness the process.

The Leica Nova MS50 allowed Cogburn to do all the fieldwork without additional crew members, but he and the manager were not the only ones at the first site. Although Cogburn was comfortable using the robotic total station, he had never used a laser scanner to measure aggregates. Jamie Gillis of Geomatic Resources, a Leica Geosystems dealer in Texas, met Cogburn before the first scans for some on-the-job training. They performed a few samples at the site, choosing various silos and piles of materials until Cogburn was comfortable continuing on his own. “The training aspect in the field was obviously a huge part of getting us off to a successful start,” McMillan says.

Cogburn discovered that the scanning setups made the process much safer than he’d expected. He didn’t need to climb over the piles or set up in precarious positions around or inside the bins in order to collect points. The laser scanner could be set up near a pile in one location for the entire scan, and many of the bin contents were scanned from positions on catwalks.


Streamlining Field and Office Work

As the scans of each facility were completed, the remote data management allowed Cogburn to transmit the Leica DBX data structure directly into the MSCAD software back at the company’s headquarters in Waco. This transformed his fieldwork significantly. There was no need to register, georeference or process any of the data in the field.

In the office, Dossey was able to transition easily from the CAD software he normally used to the MSCAD software that worked with the MS50. “It was very similar to the CAD software that we’re all familiar with,” he says. The main difference is that MSCAD allows the data to be freely exchanged between the point cloud module and the regular CAD module. This meant that Dossey could work in the point cloud and the CAD engine simultaneously.

Dossey took the raw data and directly imported it into MicroSurvey CAD software. The MS50 had already registered all the points, and all of the scans were in the right place so that he could begin calculating the volume instantly. Manipulating the point cloud, he extracted only the aggregate material data, exported the data to a DWG to build a surface, and then sent it back to the point cloud engine to demonstrate which aggregate pile was being calculated. These images from the point cloud engine were then included in the deliverable.


Changing Clients’ Expectations

When employees of the aggregate company on the jobsite observed the integrated scanning process Cogburn used, they commented on how different laser scanning is from conventional survey methods. The main differences, they said, were in the efficiency of the scans and the accuracy of the results. “We understand the conventional processes,” Dossey says. “We’ve been there. In our careers before we started 1519 Surveying, sometimes our only available measuring method was to just look at the piles and attempt to estimate the volume.”

The amount of product the client cycled through created issues for the inventory process, and the client wanted to compare consecutive scans against its own calculations based on weight. As part of the project, Cogburn went out two months later to perform additional scans on two of the previously visited sites.

Another firm had been hired in the past to perform this work and collect the data with conventional survey methods. The results took much longer, cost more and, most importantly, were not accurate. “A surveyor could perform the most accurate topographic survey in history with a prism rod and total station,” Dossey says, “but the number of points and the density of the data with the scan gives us infinitely more accurate volume results.”


Achieving Rapid Results

Even though Cogburn performed the scans efficiently and effectively from the beginning, he was able to reduce his time in the field significantly with each subsequent site he visited. At the first couple of sites, he scanned more than was necessary. As he continued, he adjusted the range in order to make the scans quicker and more effective. “It was a learning process,” says Dossey. “By the end of the project, we understood well how to optimize our time at each facility.” The sizes of the nine facilities differed, but the average scan time for each facility was about half a day.

Performing the scans quickly was one of the factors in meeting the time constraints, but there was another key factor involved. The aggregate company’s high volume of business required the information from the scans to be delivered almost immediately in order to maintain accuracy. The sites were scattered throughout Texas and Oklahoma, so if something was missed at a site, it would have been catastrophic to the client’s budget. The MS50 allowed Dossey and Cogburn to sidestep the potential for this disaster.

As soon as he finished a scan, Cogburn put the DBX raw data structure on an SD card to email or loaded it directly to the server. Within five minutes of completing the scan, Dossey was able to look at it in the office back in Waco. Since the scans did not need to be stitched together, he knew immediately whether more information was needed. Before Cogburn had time to get the MS50 instrument back in the truck, Dossey could clear him to go on to the next site.

All of the volume reporting was delivered back to the client on the same day as the data collection at each facility, as well. “It scares me to think of being under that pressure to survey all that material with traditional equipment,” Dossey says. “I don’t know how it would be possible to meet their time constraints and report the volume calculation that quickly after the fieldwork.”


Delivering Better Aggregate Inventory Solutions

Dossey and McMillan were pleased with the results of this venture, as was the client. “The MS50 is perfectly suited to do that size of scan and deliver that amount of data,” Dossey says.

There was also another benefit to this approach. Using an integrated scanner provided the versatility to handle whatever work was needed in each situation. “We use the MS50 in all of our processes,” says Dossey. “It’s an incredible robotic total station, as well as a laser scanner, so it generates revenue for us every day even when we’re not scanning.”

The deliverables on this project were simple to relay once the data was collected. The numeric volume numbers were overlaid with scan images of each facility, which were shown as a triangular mesh surface for each bin and pile being reported.

Ultimately, while the client wanted to know that 1519 Surveying used the latest technology to provide the information they needed, the details about the process were not as important. “We enjoy using the technology and seeing how the answer is generated,” McMillan says. “The client doesn’t care about all that, though. They just want a quick and accurate number, and that’s what we’re able to give them with the MS50.”

Adds Dossey: “That’s been our goal with laser scanning from the beginning. We want to provide the best solution for our clients.”

 

Beth Wilson is a freelance writer based in Bremerton, Wash. For more information about 1519 Surveying, LLC, visit www.1519surveying.com. To learn more about integrated laser scanning, visit www.novalearningnetwork.com.