Rex Robison’s sewer-cleaning business was so good that it kept him out of college. But that was only the beginning.
Seventeen years after he went into business in his senior year in high school, Robison has seen his company, R&R Visual Inc., grow from a garden-variety sewer operation serving his home state of Indiana to a specialized inspection service that covers the world with cutting-edge technology.
Robison never did get that college degree, but he has learned a lot on the job. His technical interests even took him on a side trip of sorts, bringing new techniques and equipment to inspections well outside the sewer business. Now he’s coming full circle, applying some of the same technology, mainly laser and sonar inspection, in the sewer business again.
“We work worldwide now,” says Robison, whose company is still based just outside Rochester, Ind., where he grew up. “It’s really focused on inspection. We will do cleaning if we need to, but we don’t keep a large stock of cleaning equipment.”
Inspection is another story. Robison says sonar and laser technology are opening whole new vistas for sewer inspection, offering more reliable and detailed ways to assess and measure the conditions of clogged or obstructed sewers. The company’s stock in trade is “taking on the tough and near-impossible projects.”
High school job
Robison’s father owned a septic tank cleaning business, and Robison often accompanied him to the annual Pumper & Cleaner Expo, where they studied innovations coming on line for the industry. “It was always interesting to see the new technology,” Robison says.
All set to go to college, Robison decided to take a year off to earn some money. In his senior year in high school in 1991, he bought a sewer cleaner and began offering his services to municipalities. While Robison helped his dad on septic cleaning jobs, dad would help him on sewer cleaning. “We kind of fed off each other,” Robison says.
“I started doing really well, so I thought, ‘Well, I’ll buy a camera system,’” Robison says. His first camera was a Pearpoint black-and-white push camera. His father urged him to go to more trade shows and get to know the industry in Indiana. Business grew. In 1993 Robison changed the name from R&R Sewer to R&R Visual and began focusing mostly on inspection.
In a few years, he spread beyond sewer work, using sonar devices to study levees. Then a private contractor hired his company to use its sonar gear to study vertical shafts for pillars used to support bridges. Bridges typically rest on pillars sunk into holes 48 inches or more in diameter on the bottom of the river they cross.
It turns out that the shafts are often less straight than engineers on the project assume, Robison says. On his first such project, he and his customers learned a lot. “We were able to produce a 3-D model and show them how big the shaft was, if there was any sloughage falling off the walls, if there were any cavities coming off the side, if the course was rough or smooth, and also which way it was leaning,” Robison says.
Those findings were important because variations in the shafts required tweaking in the bridge design to spread the load properly. Partnering with a load-testing company, R&R Visual began working with state departments of transportation, large contractors, and the U.S. Army Corps of Engineers. State officials began specifying the use of sonar detection methods to prove vertical shafts in construction projects.
“They use our system to check the verticality of the shaft and also the roughness of the walls, and at the bottom, whether it is flat or concave,” Robison says. Contractors, in turn, used the data to determine how much concrete they would need to fill the shaft.
The company brought its technology to other industries, including the nuclear power and petrochemical industries.
Back to the sewers
About six years ago, R&R Visual returned to its roots, with a whole new twist. Having built a depth of experience and the in-house knowledge and staff to conduct niche inspection applications with sonar and laser equipment, Robison began marketing those techniques to the sewer business.
“We thought this would take pipe inspection, sewer inspection with sonar, to a level where it’s meaningful,” Robison says. That’s because sonar and laser techniques provide a great deal more information than traditional CCTV.
Sonar inspection uses a transducer that spins at the end of a tether, sending out sound waves and calculating the time it takes for them to bounce back. The speed of sound varies with the temperature of the water it passes through. The transducer and its software use the data to construct an accurate image of the profile of the pipeline.
Laser inspection uses a profiler attached to a conventional CCTV camera. The profiler projects a beam of laser light that makes a ring on the pipe surface as the camera moves through. The result creates images that can be accurately measured with the help of specialized computer software.
Both technologies enable inspectors to get detailed measurement information unavailable from a TV image alone, says Robison. “Instead of recording a video image, we’re actually producing three-dimensional models where we can do measurements and get a lot of useful data to engineers.”
The biggest demand for sonar sewer inspection has been for interceptors. “With large-bore sewer lines where you’re getting over 24 inches in diameter, the problem for cameras is that usually the flow is too high to be able to get a camera through it,” he says. Bypassing wastewater to get the line dry enough for a camera is expensive.
A sonar unit can be mounted to a raft and floated through the line. And its benefits don’t stop there. “Sonar is very useful for checking the geometry of a pipe,” Robison says. It can produce measurements that show if the pipe has become deflected or corroded and can identify places where the line has produced misshapen bellies.
Mapping debris
But perhaps the biggest use for sonar in sewers is to detect how much debris or sediment is in the bottom of a pipeline. Cities that have combined sewers may use their sanitary sewers to retain stormwater. “If they have a lot of sediment and debris in the pipe, they’re just using up useable storage area.”
A camera can’t really detect how much debris is under the water, and visual inspection usually offers just rough and often inaccurate assessments. A contractor called to inspect a 70-inch pipe carrying 60 inches of water “doesn’t really know how much debris is in the bottom,” says Robison, and the actual depth of the debris can be very uneven. “So their pricing for doing pipe segments is very expensive.
“With sonar, you can go through and pre-inspect it. You would float it through on a raft or drive it through on a robot. We can measure the distance from the waterline – the sonar head – to the bottom of the pipe, and we can see how much sediment is there. We’re capturing this information at different intervals.” The process can create a precise profile of the debris and give cleaners a clearer understanding of the extent of the problems they face.
With the aid of imaging software, “We can produce a 3-D model and calculate how much sediment is throughout that entire pipeline,” Robison says. “We also graph that, so when the customer hands this report off to a contractor and says, ‘We want this pipe clean,’ the sewer cleaner can give an accurate quote.” Municipal customers also use sonar to help with quality inspection after a cleaning job is done.
Satisfied customers
In Indianapolis, Ind., MS Consultants, an engineering and architecture firm, worked for three or four years with R&R to conduct sonar and CCTV inspections of Indianapolis sewer lines over 36 inches in diameter. Jayson Watt, MS Consultants’ resident project representative for Indianapolis, says the sonar provided inspection data that CCTV could not.
“The sonar would actually give us an estimate of the amount of debris that was in the line, so we could further assess the amount of cleaning needed,” Watt explains. “We were able to determine more efficiently if a specific project required heavy cleaning versus light cleaning.”
Visual inspection was still required to determine the specific content of a blockage, but by getting a more precise measure of the debris volume that sonar provided, “We could base the cleaning contract specifically on the level of the debris,” says Watt.
The engineering firm Lawson & Fisher Associates of South Bend, Ind., hired R&R a few years ago to use laser profiling to inspect PVC pipe at a new construction project. The pipe was holding water in spots. A mandrill fed through the line to check it was blocked where the line was out of round, but the extent of the problem wasn’t clear. “With CCTV, we could see there were dips in the line,” says Lawson & Fisher’s Peggy Biggs. “But there was also a lot of debris in the line. It was very difficult to tell if it was debris or a dip in the line that was holding the water.”
A laser inspection filled in the missing information. “All we knew was, we had two spots that were out of round,” says Biggs. “Profiling helped us define how much of the pipe was out of round.”
Based on the evidence, the municipality ordered the contractor to redo the job. Biggs says laser technology also can help with inspecting old, deteriorating pipe. “You can get a lot better measurement on what the degree of degradation on the pipe is,” Biggs says. That can allow a much more precise assessment of the urgency of repairs or replacement.
Staying focused
Robison uses gear from a number of sources. Currently the firm uses 1512 profiling sonar transducers from Marine Electronics Ltd., based on the isle of Guernsey in the United Kingdom, along with an Imagenex 881A Profiling Sonar. Laser systems include three Cleanflow Systems Clearline Profile models, specified for one of three different cameras. The camera inventory includes a list of several IBAK and Pearpoint models, along with accessories.
Surprisingly for a company that started in the sewer-cleaning business, R&R owns only one piece of cleaning equipment, a 2000 jetter from O’Brien Mfg. (a division of Hi-Vac Corporation) that operates at up to 4,000 psi/18 gpm. For other cleaning needs, the company rents equipment.
And that’s the way Robison expects to keep it. Sewer cleaning may have started him on his path, but it’s the inspection he thrives on today. In a field where the technology never stands still, he expects new developments to keep coming. And when they do, R&R Visual will be ready to try them out.
