- SPECIAL REPORTS
- THE MAGAZINE
John Krcmar had been involved in a lot of surveys in his 33 years with Canadian Pacific Railway (CP). But he had never done one like this.
As part of his job as a district claims and litigation representative for the railroad, Krcmar investigates accidents and collects evidence and information. In October 2009, Krcmar went to an incident at a pedestrian crossing in Winona, Minn. Because the crossing was scheduled for removal, Krcmar needed to quickly preserve the scene with as much detail as possible. Normally, Krcmar would call for a survey of the site, which would be done using a total station or GNSS technology. Based on a suggestion from a colleague, Krcmar instead contacted Shive-Hattery, a design and consulting company headquartered in Cedar Rapids, Iowa.
As impressive as the scanning technology was to Krcmar, for Shive-Hattery it was a natural evolution. Ambort’s presence at the rail crossing was the result of a deliberate planning and decision process. “We like to be at the front edge of technology and known as experts in our field to our clients,” says Myron Scheibe, Shive-Hattery vice president and director of the firm’s office in Moline, Ill. “And we’ve done that, whether it was the first EDMs, total stations or GPS and GNSS. Now it’s with scanning.”
An employee-owned organization with seven offices and more than 300 employees, Shive-Hattery provides surveying, engineering and related services to its clients in the Midwest. According to Marketing Director Greg Kanz, the firm saw that its land survey business was changing and that it needed new ways to grow. A key approach was to find a way to complement the firm’s existing services in a way that would add value for its clients.
Rick Brackey, survey group leader at the firm’s Moline location, had long watched the changes in surveying being spawned by new technology. One example was the way machine control was changing stakeout for construction survey layout work. Brackey was seeking other services to provide to his clients, and a breakthrough came at the Trimble Dimensions 2005 User Conference. “I attended several seminars at Dimensions,” Brackey recalls. “There was a flood of ideas from people who were using 3D scanning. I went back to my hotel room and started writing about what we could do and all the possibilities for it. Two months later, we rented a Trimble GX.”
The ensuing six-month rental period was part of a rigorous analysis and justification process by Shive-Hattery. The company wanted to understand what the scanner could do for its clients and how it would generate a return on investment.
In the end, Brackey says, it was a straightforward decision. When Shive-Hattery purchased its first GPS surveying system more than 10 years ago, the firm had conducted a similarly detailed evaluation before selecting Trimble equipment. Now, the firm wanted a new scanner that would work with its existing Trimble GPS and total stations. The numbers and opportunities added up, and Shive-Hattery purchased its Trimble GX Scanner in November 2006. Since then, the team has had little trouble keeping the scanner busy.
Lafarge North America’s Davenport Cement Plant in Buffalo, Iowa, mines limestone and produces approximately 1 million tons of cement annually. Lafarge N.A. has a long relationship with Shive-Hattery, contracting the firm initially to measure stockpiles and later to determine the volume of overburden stripped from above the limestone.
In the spring of 2007, Brackey arranged to do a test project with the 3D scanning system for Lafarge N.A. Quarry and Mobile Equipment Manager Joe Foss. For the trial, Shive-Hattery scanned a stockpile as well as the quarry face and gave Foss results from both surveys. “We’ve been going with the scanning method in the quarry ever since,” Foss says. “It’s less time consuming, less labor intensive and gives better results.”
The deliverables have changed, as well. Prior to using scanning, technicians extracted cross sections from conventional survey data and used prismoidal or average end area methods to compute volumes. Lafarge N.A. received plan views, cross sections and volume reports. Today, Shive-Hattery provides plan views, but cross sections are no longer needed. Instead, volumes are taken directly using surface-to-surface comparisons.
The detail provided by the scanner is important to getting accurate results. “It can be difficult to determine the division between the layers of overburden,” Foss says. The overburden includes a layer of cap rock that ranges from 5 to 30 feet deep as well as a variable layer of clay. “They download the data, and we can look at it in 3D to make sure the interpretation is correct.”
For Foss, the value of the services from Shive-Hattery has increased. The results come back much faster, and Lafarge N.A. is receiving more-detailed information at a cost similar to traditional methods.
Shive-Hattery also found a new application for its existing clients in cellular communications. For years, the firm had conducted location surveys for new cellular towers. Brackey learned that the tower owners often need accurate as-built information on the towers themselves. The owners want to know what components are on the towers and determine if there is room to lease out more tower space. “In the past, somebody had to go out and climb the towers,” Brackey says. “That means taking some things out of service, which costs money. And, of course, there is the safety factor. We can scan a tower for the same cost or less--and get much more information.”
Shive-Hattery has found similar applications in scanning water towers using the Trimble GX to collect detailed information on the large, difficult-to-access structures. Scanning a typical water tower takes four to six hours in the field. Ambort uses a Trimble S6 Total Station to set ground control around the structure. He then places the scanner and its targets on the control points. Before leaving the site, Ambort registers the scans into a single point cloud and verifies that he has a complete, accurate dataset.
In its offices, Shive-Hattery uses Trimble RealWorks Software to manage the point clouds, images and visualization coming from the Trimble GX. From there, the information goes to the AutoCAD design systems used by the company’s engineers and architects.
Ambort and Brackey say that survey workflow provided by the Trimble GX reduces the learning curve and makes it easy to tie multiple scans together. But they both are experienced in the challenge of how to best approach a 3D scanning project. “The fieldwork is not much different than any other kind of surveying,” Brackey says. “But it’s a little different way of thinking about what you are picking up and getting two sides of things if you need it. You learn to kind of think in 3D.”
The transition to 3D data affected Shive-Hattery clients in different ways. “Some people adopt it very effectively,” Scheibe said. “There are others who are quite accustomed to 2D drawings. They may struggle to grasp or understand the 3D information.” To smooth the transition, Ambort and the other surveyors spend a lot of time making sure clients can take advantage of the information they collect with the scanner. They routinely provide clients with a Trimble RealWorks Viewer, a complimentary, downloadable Trimble utility, along with written instructions on how to use it. Shive-Hattery also provides services to create animations and flythroughs of the 3D data.
As scanning continues to grow, acceptance will become widespread. Kanz believes that 3D scanning is already moving toward the mainstream of surveying. “We’re seeing more competitors getting involved,” he says. “And it is starting to show up more often in RFPs from the government.”
Brackey’s approach to introducing scanning was a good one. By first presenting the scanner to Shive-Hattery internal staff, he established wide awareness of what it could do. A grassroots effort emerged to carry the message to the company’s clients, and the scanner continues to open doors beyond the traditional surveying business. Work at accident scenes for clients like CP has emerged as a good opportunity, and Scheibe says they are also working in other areas, including building restoration and industrial plants.
As an example, Scheibe points to a large manufacturing plant near Moline. The owner wanted to replace the windows in a multistory industrial building at the Rock Island Arsenal in Rock Island, Ill. They needed measurements of the existing windows and openings. The windows were large (20 feet wide by 40 feet tall) and difficult to access. To complicate matters, the work to measure the windows had to stay clear of the ongoing industrial operations. Ambort used his Trimble S6 Total Station to set control points around and inside the building. Without interfering with plant operations, he captured interior and exterior scans. The 3D data provided precise dimensions on the window openings, and engineers created 2D drawings and cross sections to look for interference or other problems in installing the new windows.
The technology is also allowing the firm to increase the safety and productivity of its survey crews. For example, a recent project on the University of Iowa campus in Iowa City required surveys of a steam tunnel running beneath an intersection that was slated for maintenance and rehabilitation. The work would be difficult since the intersection involved two major thoroughfares and a bridge over the Iowa River. Ambort set up the Trimble GX 3D Scanner on two pedestrian overpasses above the intersection. In just a few hours, he scanned the area to gather detailed data on the surface conditions. The scanning was faster and gathered far more detail than would have been possible with a conventional surveyor walking in the intersection. And because Ambort could work from a safe location above the busy streets, there was no need to stop or divert vehicular traffic for the survey.
Looking at the past three years, Scheibe said there is little the firm would have done differently. Similar to its previous experiences with EDM and GPS, the results have been good. “We were probably a little farther ahead of the curve than what we normally would be,” Scheibe says. “We showed it to a lot of different people and got good reactions to it. It was a solid investment, and it has given us a real strategic advantage.”
Krcmar remains in awe of scanning and how Shive-Hattery is bringing the technology to its clients. “There are tremendous benefits from the cost perspective,” he says. “When we knocked on Shive-Hattery’s door, we were amazed at what we found, and how they had committed to investing in technology that would benefit us.”