ROVs complement divers and play key role in inland operations
By Nick Fortuna
It was a grisly discovery that brought closure to one family struck by tragedy and proved once again, ROVs can be an invaluable tool in inland commercial diving operations.
Last May, an ROV owned and piloted by the Great Lakes Water Studies Institute at Northwestern Michigan College located the body of 53-year-old Emanuel Manos. Earlier that month, a Beech Craft Bonanza 35 with Manos and one other Michigan man aboard had crashed into Lake Michigan after experiencing engine trouble.
Investigators found the small airplane in 515 feet of water and used a rover with a video camera to search for the two bodies, to no avail. But the Saab Seaeye Falcon ROV soon found Manos’s body near the crash site, 531 feet beneath the surface, making it the Michigan State Police Marine Services Team’s deepest body recovery on record.
“That was something that only an ROV could do,” said Hans VanSumeren, director of the Great Lakes Water Studies Institute. “We would not be able to put a human down that deep — not in the Great Lakes. We were able to retrieve the victim using the manipulator on the ROV, and that’s very rewarding work because we were helping our Michigan State Police Marine Services Team, which is doing amazing work in the Great Lakes, so they could bring that body back to his family.”
In the inland market, ROVs aren’t sent on the deep dives seen every day offshore, but they are being put to good use. Common applications include inspecting pipelines, bridges, dams, nuclear power plants, hydroelectric facilities and potable water towers, along with research into fisheries and freshwater ecosystems and the recovery of bodies and evidence.
Patrick Murphy, founder and president of Painesville, Ohio-based Lake Erie Diving Inc., said he recently used an ROV to inspect a 6,100-foot-long pipeline in Lake Michigan in less than four hours, taking advantage of the clean water conditions and high visibility to move the ROV along at a steady clip. In early October, he was planning to travel to Virginia to perform several dam inspections using ROVs.
“It’s just the easiest and least-expensive way to do it with deeper dams,” Murphy said. “They don’t replace a diver, but they certainly make things a lot easier sometimes.”
Working alongside divers
Amid increasing automation and technological breakthroughs, workers in many industries are wondering how long it will be before they are replaced by machines. But Murphy said commercial divers shouldn’t worry about diminishing job security due to ROVs. In fact, using divers in conjunction with ROVs is sometimes the best way to complete a job.
One recent example came when Murphy was using an ROV to locate and recover an engine that had fallen off an airplane over Lake Michigan. The engine was submerged 250 feet below the surface, and getting to it would require some fancy flying.
“There was a lot of rope in the water, and ropes and ROVs don’t get along too well,” Murphy said. “Any ropes flowing around in the water usually get sucked into it, and then you’re done. It was 50/50 whether I was going to get the job done or get stuck. We had a mixed-gas dive crew onsite and we talked about it beforehand. If I did get stuck, the divers would cut it loose. I wouldn’t have done what I did without having those divers there because I knew the risk.”
Murphy said that although an ROV’s manipulator can be used for many tasks, the superior manual dexterity of divers ensures that they always will be a part of the equation. Complex tasks such as underwater assembly, pumping mud to remove sediments, drilling holes in concrete, pouring concrete and using tools such as ratchets and wrenches still require a human touch, he said.
“An ROV could not do those kinds of things,” Murphy said. “ROVs are never going to replace the diver in shallow water. Sometimes we’ll put the ROV in if it’s an environment where there could be a hazard. We put the ROV down there to make sure it’s safe for the diver to go, but that’s the only reason I would put the ROV in instead of a diver in shallow water. I constantly tell my clients that I could live with losing my ROV; that’s not the end of the world, like hurting somebody.”
VanSumeren said he sees ROVs and divers playing complementary roles in many inland operations. “I’ve been on plenty of jobs recently were an ROV and the diver were both required to complete the tasks, and neither one could complete the whole job on their own,” he said.
Chris Gabel, owner of Elverson, Pa.-based Ocean Eye Inc., which specializes in professional diving equipment maintenance, products, manufacturing and consulting, said divers’ ability to “feel around” underwater and perform a wide variety of tasks, including removing sea growth from structures, makes them irreplaceable. In addition, local, state and federal regulations often require inspection work to be done by a human diver, Gabel said.
“The requirements for bridge inspections and a lot of things like that have not caught up to the technology,” Gabel said. “There are a lot of situations in inland diving that still require a human to get in the water and get a firsthand look, rather than being able to send an ROV in. Eventually, that may change, but the preferred methodology of many of the municipalities is that you need to go in and do it personally.”
Triaging infrastructure needs
Still, ROVs are a critical tool for subsurface inspection of infrastructure, especially in deep water, said VanSumeren of the Great Lakes Water Studies Institute. He pointed to the nation’s infrastructure getting a D+ grade on the 2017 Infrastructure Report Card from the American Society of Civil Engineers, and said ROVs can help transportation officials identify the most urgently needed infrastructure repairs.
According to the U.S. House Budget Committee, fully addressing the nation’s infrastructure needs over the next decade would cost $2 trillion more than currently projected funding levels.
“I do think the need [for ROVs] is increasing because of the age of most infrastructures in the U.S.,” VanSumeren said. “With limited resources, meaning dollars, there’s a need to better understand what is imminently going to fail vs. what has more time, and so the inspection and monitoring of infrastructure through the use of ROVs allows the manager of the dollars to make better, moreinformed decisions.”
VanSumeren said that in the Great Lakes, the school’s ROVs often are used to explore newly discovered shipwrecks and to deliver and retrieve scientific instruments deep underwater to record data over time. One such project involves working with the National Oceanographic and Atmospheric Administration in Lake Huron.
Scientists have located groundwater discharge areas that have created submerged sinkholes in the lakebed about 300 to 400 feet underwater. The school’s ROV will deliver instrumentation to the lakebed and retrieve it up to a year later so scientists can study the chemical properties and bacterial lifeforms in and around the venting water. Researchers also will gain a better understanding of the seasonal variations in water properties.
“Someone asked me what the most interesting thing I’ve found on the bottom of the Great Lakes was, and I said it was these sinkholes,” VanSumeren said. “We are really looking at some very unique bacterial-based lifeforms that just don’t exist in other places on the planet. So, ROVs were critical in the support of that science, and working with those scientists is something that I and many of our students find very exciting.”
Though he prefers to use divers in depths of up to a hundred feet, Murphy said Lake Erie Diving’s five ROVs stay busy and pay dividends. Having bought his first ROV in 1998, he’s about as experienced a pilot as can be found anywhere.
For one of his smaller ROVs, he has an umbilical cable measuring 6,800 feet, which means it can go more than 1 1/4 miles down a pipe that is 24 inches in diameter or bigger.
“It’s a very small, very powerful vehicle,” Murphy said. “The ROV can stay down 300 feet all day. It doesn’t get cold, it just works. It does what you tell it to do. There are a lot of complications that come along with putting a diver at depth, and the ROVs make it so easy.”
On one recent project in Indiana, contractors wanted to dewater a caisson but couldn’t because a vertical pipe sticking up from the bottom was leaking. To plug the leak in the 3-inch-diameter pipe, Murphy and his team used a crane to lower a 170-foot-long, 1-inchdiameter pipe toward the bottom. Murphy then used the ROV’s manipulator to place the 1-inch pipe inside the 3-inch pipe, and the team poured grout into the smaller pipe, sealing the larger pipe.
On another recent job, Murphy was helping to lay a power cable in a body of freshwater when it got stuck on a large rock. He then tied a rope to an aluminum angle iron, placed it in the ROV’s manipulator and was able to get the line under the cable. The crew then used the boat to pull the cable over the rock and continue with the job. Murphy said that without the ROV, divers and support staff would have been necessary to free the cable.
“That saved many thousands of dollars there, and it took an hour,” said Murphy, who spent 10 years as a machinist before becoming an ROV pilot. “I make a lot of special tooling for my ROVs. Being creative with these vehicles is fun, and I enjoy it. There are applications where they’re a great tool.”