Small, relatively cheap commercial robots are making a big play for one of the most crucial maintenance jobs on Navy ships.
Earlier this month, the Mid-Atlantic Regional Maintenance Center (MRMC), a division of Naval Sea Systems Command, hosted a demo aboard the amphibious assault ship Iwo Jima in which a VideoRay Pro 4 remotely operated vehicle, or ROV, submerged inside a large ballast tank and used its cameras to inspect the walls for rust, corrosion and other flaws.
According to an MRMC news release, the Feb. 16 demo was attended by 20 leaders in ship maintenance and led by a team from the Puget Sound Naval Shipyard and Intermediate Maintenance Facility near Seattle. Iwo Jima, which typically deploys with Marines on board as part of a three-ship amphibious ready group, changed its homeport from Mayport, Florida to Norfolk, Virginia just ahead of a drydock maintenance period that cost the Navy $200 million and will take the better part of a year. Ship maintenance is time-intensive and expensive, and the Navy is constantly behind schedule.
That’s why a tool that could save time and free up manpower has immediate appeal. And it seems that the Navy’s ship maintenance leaders are seeing the value proposition.
The VideoRay Pro 4, which weighs less than 14 pounds and has been used commercially to assist dives, explore underwater shipwrecks, conduct maritime research and perform ocean side surveys, patrolled a 9,000-square foot ballast tank on the Iwo Jima. It recorded images of the tank’s sides that will be compared to the findings of a traditional dry-tank inspection when the ship’s maintenance availability begins in earnest this summer. The mini-sub, just over a foot long, can operate at depths of up to 1,000 feet. Similar models sell for about $15,000.
“We were able to get a pretty clear and accurate view of the inside of the tank,” Ty Curtin, MARMC Tanks, Voids and Structural Branch Head, said in a release. “We could see a lot of items in this tank that were documented previously by our assessors.”
Inspecting the tanks and voids, or T&V, of a large Navy ship is a major and high-stakes undertaking. Tanks carry fresh and wastewater, fuel, oil, and other fluids used by the ship; voids are small, unused dry spaces that are also subject to corrosion over time. A Nimitz-class aircraft carrier has about 1,000 of these spaces. While sophisticated coatings have mitigated the corrosion that used to be a major problem for the Navy, a faulty tank can still scuttle a deployment: last year the Ticonderoga-class guided-missile cruiser Vella Gulf headed back to port shortly after departure due to a corroded fuel tank that caused a leak.
And while inspections are crucial, they take a lot of time, most of it spent on ensuring the environment is safe for a human diver. According to the release, tanks often have to be emptied and completely dried out to make them safe for inspection. A 2011 presentation delivered at that year’s DoD Maintenance Conference stated that 4,000 shipboard tanks were inspected every year at a cost of $32 million, or up to $15,000 per tank.
“There’s an entire process we have to go through before we could get someone into a tank to conduct an inspection that most times takes only a couple of hours to complete,” Kevin Baum, MARMC Ventilation and Damage Control Branch Head, said in a statement.
“On the [destroyers] and [Ticonderoga-class cruisers], where stability is critical, having the ability to conduct an accurate and descriptive inspection or check on a specific issue without having to go through that preliminary process could be a game changer for us.”
It’s a game-changer that has been a long time coming. In 2010, the Navy posted a solicitation that described in detail the problems with human inspections and asked for an autonomous solution.
“Agile, trained inspectors are required to enter the tanks with several pieces of gear climbing through myriad manholes and narrow passageways in order to inspect and document the condition of every square-inch of surface of that tank,” the solicitation, describing a Navy carrier, stated.
“Additionally, requirements to gas free engineer these spaces requires additional manpower and effort, and reduces the flexibility to conduct other maintenance simultaneously. Developing a method to autonomously inspect tanks and voids could reduce costs greatly, reduce hazards for the inspectors, and provide better consistency in assessments.”
When military leaders discuss robotics, they often talk about the three D’s: dull, dirty and dangerous work, where a machine represents a safer and less taxing solution than a human. In the military, where uniformed manpower comes prepaid, sometimes the incentives for using robots to do grunt work are not as apparent. But the time crunch and high demand associated with Navy tank inspection and maintenance heighten the appeal of autonomy.
ROVs are also being tested out at the Norfolk Naval Shipyard Technology and Innovation Lab. According to an August 2021 release, a diving robot known as the Deep Trekker DTG3 was used to inspect tanks on the Carrier George H. W. Bush in a proof-of-concept exercise. Next, the release adds, the ROV may be used to inspect another carrier, the Dwight D. Eisenhower, as well as other Navy ships.
“The ROV is expected to complete these inspections more rapidly than the current processes and can ensure the safety of personnel by no longer sending divers under the ships,” it states.
What’s not yet clear is when these inexpensive diving robots might be universally employed for tank inspection across the Navy. Calls to NAVSEA did not receive an immediate response.
The Navy has already invested millions in Video Ray ROVs for other purposes. According to Seapower Magazine, Video Ray Defender systems purchased under a $49 million contract in 2020 are being employed by the Navy for “defense and security operations including very shallow water, littoral mine countermeasures, port security missions and hull and pier inspection.”
The release about February’s robotic demo on board the Iwo Jima does not commit to the next steps, but says the Navy is “looking at the possibility” of using ROVs more broadly in service regional maintenance centers and other facilities.