A model of Marine Tech’s Manta undersea drone displayed at Euronaval 2022. (Christina Mackenzie/Breaking Defense)
EURONAVAL — One topic that was top of mind here at Euronaval was the bottom of the ocean — specifically both defensive and offensive seabed operations to protect, or attack, critical infrastructure, in light of the suspected sabotage of the Nord Stream gas pipeline off the coast of Sweden last month.
Seabed warfare is not new, according to former Royal Navy clearance diver Chris Lade who is today the defense sales manager for Saab Underwater Systems. “It’s been around for a very long time with mine warfare, but it’s what’s on the seabed that’s changed. Today there are communications networks, pipelines, power cables, and the threat against them is real.”
Nations have grown increasingly concerned about and intrigued by the vulnerability of those networks and cables in recent years, so much so that in February, France’s then-Minister of Armed Forces Florence Parly and current Joint Chief of Staff General Thierry Burkhard unveiled a new “Seabed Warfare Strategy” aimed at broadening the French Navy’s undersea capabilities up to 6,000 meters (19,685 feet) deep, which, according to Lade, seems to have set the “go-to depth.” To put this in perspective, that’s more than deep enough to reach the average depth of any ocean, but not enough to reach into their deepest trenches.
Though it was publicized months ago, one of the first actual moves in the new French strategy was revealed on Thursday by the DGA procurement agency when it announced it had signed a €4 million ($3.9 million) contract with Norwegian company Kongsberg Maritime. The contract, signed in mid-August, was for trial tests of a Hugin Superior Autonomous Unmanned Vehicle (AUV) which can operate in depths of up to 6,000 meters.
The two major challenges for operating equipment that deep is the pressure, which is about 614 kilograms per square centimeter, or 8,733.1 pounds per square inch. In comparison, the pressure of the Eiffel Tower on the ground is 46.7 pounds per square inch. Then there’s the trouble of getting data to and from the equipment that deep.
But there are additional challenges in seabed operations, Lade told a group of journalists at the show. “Currents, because systems won’t stay put. Acoustics, used in sonars, that change according to salinity and depth. Visibility, which can be good or very poor, and of course weather which is a major factor, not forgetting the sea-bottom itself which, just like on land, can range from mountain ranges to deserts.”
Lade said initial capability requirements are defensive “and I think these will be akin to mine warfare, ensuring that you know the seabed and run a review of your assets every six months.” He suggested “some sort of alarm system” provided by sensors might be needed.
As for offensive capability “you want to interdict, monitor or reconnoiter a threat on the seabed.” For both capabilities “you might want to be covert,” he added.
They’re all challenges that Kongsberg, began addressing decades ago. Richard Patterson, Kongsberg Maritime’s director of sales for marine robotics (defense), told Breaking Defense at the show that the Hugin AUV was developed with the Norwegian Defence Research Establishment (FFI) in the early 1990s for mine-hunting and was first used for commercial offshore pipeline route surveying in 1997. About 6.5 meters (21.3 feet) long, 870 millimeter (34.3 inches) in diameter, Hugin is depth rated to 6,000 meters. It can either be controlled by an operator via an acoustic tether or be autonomous in which case needs no tethers or cables. Patterson explained Hugin is equipped with a high precision acoustic positioning system (HIPAP) which is what allows it to be operated at such great depths without getting lost.
The Hugin Superior was tested by the French Navy earlier this month from the Beautemps-Beaupré hydrographic and oceanographic survey vessel. France will also rent a number of other currently available French and European AUVs and Remotely Operated Vehicles (ROVs) to test and compare them so that the DGA, in collaboration with the French Navy, can define a concept of use. The ultimate aim is for France to have sovereign capacity in deep sea equipment.
French requirements also could be met by the Manta UHV (unmanned hybrid vehicle) that can function deep on the seabed. The Manta, which looks like a shiny, silver metal wing, was partly funded by the DGA’s AID Defense Innovation Agency and partly by Marine Tech, an eight-person company based in the Mediterranean port city of Toulon.
To develop the Manta, Marine Tech created another firm, Marine Garde, with its partner Hologarde, a 100% subsidiary of Aéroports de Paris. The all-electric Manta has been designated as an unmanned hybrid vehicle (UHV) by the DGA because not only is it depth-rated to 6,000 meters but it can also swim just under the water surface without leaving any wake, or can float just like a boat. (Coincidentally, the US military’s fringe research office, the Defense Advanced Research Projects Agency (DARPA) also has an unmanned undersea program called Manta Ray.)
Thierry Lamaire, Hologarde’s managing director, told Breaking Defense that the wing-like shape gives the UHV “tremendous agility so it can fly horizontally but also almost vertically making it easy to survey sub-sea cliffs, for example.” The pressure problem has been solved by placing slits in the UHV’s envelope that allow water in “so there is no pressure inside the UHV at all.”
The antenna, which can be up to three meters (9.8 feet) long carries a camera at the top and the communications systems are in the mast itself. “But we are sensor agnostic. Clients can put any of their own sensors on Manta,” Lamaire said. For the moment Manta, which is not a prototype but a real product, has eight hours of autonomy, “but by the end of 2023 we will have increased this to 24 hours.”
Philippe Roumegue, marketing director for remotely operated vehicles at the newly formed Exail defense firm, told Breaking Defense that its UAV, DriX, could also function in depths of 6,000 meters. ROVs, he said, had an operational depth of up to 1,000 meters depth because after that the distance the data had to travel in the underwater cable becomes too great.
Although Saab is the world leader in the subsea drone market, most of its products operate in considerably shallower depths. Lade explained that the company was moving away from hydraulic technology to electricity for its undersea vehicles as it is “more efficient, reliable and environmentally friendly.” It currently offers the eWROV, a four-tonne (4.4 tons) electric AUV with two manipulator arms at the front that has a depth rating of 3,000 meters (9,843 feet) and optionally to 5,500 meters (18,045 feet).
Whatever the solution, “recent events have underscored the importance of seabed operations,” Niclas Kolmodin, head of Saab Underwater Systems, remarked.
