BEATING THE MINEFIELD WITH AUTONOMOUS COUNTERMEASURES

The potential for autonomous mine hunting is now being realised - and the demand for it is growing.

Tim Fish

Technological developments in mine countermeasure (MCM) systems have been leading the way in the application of true naval autonomous systems. Restrictions on data transfer capabilities in the underwater domain limits the ability to command and control platforms. This means that platforms operating under the water need to have a higher degree of autonomy to understand the environment and calculate which actions and tasks to complete without a human operator.

Naval forces have been introducing Remotely Operated Vehicles (ROVs) for MCM operations for over two decades, but most of these have been connected to the operator on board a ship or on the shore by a cable. This has meant that the range of operations has been limited by the length of the cable. To conduct extended range, long endurance military operations subsea - and for this activity to be networked - then autonomy is essential. The use of Autonomous Underwater Vehicles (AUVs) linked together and cooperating with unmanned surface vehicles (USVs) and crewed platforms is the future of MCM and is set to revolutionise this capability.

“moving from a second-generation solution using ROVs deployed from a mothership close to the danger zone, to a third generation MCM solution with a mothership operating much farther away from the danger zone and deploying a mix of AUVs, Unmanned Surface Vessels (USVs) and even Unmanned Air Vehicles (UAS) together with ROVs.”

The Russo-Ukraine War has highlighted the importance of MCM. The effect of deploying mines is to deny sea control to opposing forces but also to prevent the continuation of trade, making them an effective tool in a blockade that can impact the local and international economy. The mere risk of hitting a mine deters warships and commercial vessels from key trade routes and ports.

Transition

MCM forces are at the start of a major transition. Modern tier one naval forces are beginning to move away from using dedicated (and expensive) single-role MCM vessels (MCMVs) such as mine hunters and minesweepers. These ships are specialised as they are built of non-metallic material and incorporate high levels of signature control and shock resistance to enable them to operate in minefields with reduced risk. Minesweepers can tow a sweeping system behind them that replicates the signatures of a large warship to encourage the mines to detonate on the false target.

Many of these types of ships are coming to the end of their service lives and instead of being replaced, packages of remote and autonomous systems are being procured that can be deployed at range from a wider variety of ships. This is part of an ongoing trend to remove people and crewed platforms out of the immediate danger areas around mines and minefields. It began with the use of ROVs that were employed to eliminate the need for divers to locate and classify mines, and has now moved to the ships themselves.

The intension is for these autonomous systems to collaborate in the detection, classification and destruction of mines at speed, providing more data for the accurate identification of mines resulting in MCM operators gaining more flexibility in their responses. To achieve this there are number of MCM procurement programmes underway to test and deliver this capability.

France and the United Kingdom are undertaking a joint programme under the auspices of the 2010 Lancaster House agreement. Known as the Maritime Mine Countermeasures (MMCM) programme, it is being led by Anglo-French company Thales, which was awarded the MMCM contract in March 2015.

The UK element is being procured under the MCM and Hydrographic Capability (MHC) programme that will see the Royal Navy’s existing Sandown- and Hunt-class mine hunting and mine sweeping MCMVs retired over the next decade. Two Sandown-class ships, HMS Blythe and HMS Ramsey, were decommissioned in August 2021 and were earmarked to be handed over to the Ukrainian Navy. The remaining five vessels will be retired through to 2025. MHC will also replace the survey ships HMS Echo and HMS Enterprise, due to the provision of a ‘toolbox’ of autonomous systems that can provide a range of capability for both hunting and sweeping tasks.

The UK’s MHC will be delivered in phases following the completion of a preliminary assessment phase. MHC Block 1 will see what the UK Ministry of Defence (MoD) terms as an initial capability insertion/operational exploitation of systems that will be operational by 2025.

The French element of MMCM, known as the Système de Lutte Anti-Mines Futur (SLAM-F) project (future counter-mines system), will only focus on a mine-hunting capability.

Under MHC Block 1 and the initial phase of SLAM-F, Thales delivered a prototype demonstrator system to each country which will be followed by three sets of complete mine hunting systems at a cost of $249.7 million (£184 million). These include: an USV from L3Harris; the Saab Double Eagle ROV in its Multi-Shot Mine Neutralisation System (MuMNS) configuration; with Thales delivering its Synthetic Aperture Mine Detection and Imaging System (SAMDIS) and four Portable Operations Centres (POCs). Initial deliveries of the first complete production standard MMCM capability sets are expected in mid-2023 in Q2 or Q3.

Matt Hunt, the maritime autonomous business lead at Thales told Armada that in order to move into the production phase “some serious and significant trials” had to be completed in the UK and France. He explained that about 140 mines of different types had to be found across four different scenarios and within each scenario there were half a dozen vignettes.

According to Hunt, the systems covered a maritime area comprising about 30,000 football pitches during the trials and achieved a probability of detection of mines “greater than 99 percent” with false alarms less than one percent. “We blew the old systems out of the water. We hunted at 8-10 knots compared to the previous 1-2kts with a greater probability of detection and classification and with less false alarm rates.

Only by completing those were we given the green light for production,” Hunt added. In April 2022 the French Navy took delivery of its first 12 metre-long USV from Thales, named Artemis. In December 2021 the RN took delivery its USV known as Royal Navy Motor Boat (RNMB) Apollo. In July 2022, the RN’s Maritime Autonomous Systems Trials Team (MASTT) announced that a second USV for the RN named RNMB Abdiel was conducting pre-acceptance testing.

The USVs are not just automated boats, they are sophisticated platforms fitted with high end equipment. This includes sense and avoid sensors to prevent collisions with other ships; seawater cooling, electricity and hydraulics to support payloads; the power to pull a towed body at 100-200m; and propulsion to allow the USV to keep station in a variety of sea states.

The USVs will pull a Towed Synthetic Aperture Multiviews (T-SAM) vehicle behind it that is fitted with the SAMDIS. Saab’s MuMNS system will be delivered from late-2022 following a $36.5 million (SEK300 million) order that the company announced was placed at the end of 2020. Each MuMNS has three mine neutraliser systems. Hunt said that the production variants will have 360 degree cameras, microphones and speakers on board to allow the system operators to see the environment and provide warnings to other near by craft.

The system has two configurations: detection and classification; and localisation and neutralisation. Either two USVs can be used, one in each configuration, or just one that can be re-rolled by changing the modules on the back. For detection and classification, the operating officer is given an area of sea to clear. Using the mission management system with software that employs artificial intelligence to find the most efficient route with the assets available.

Hunt said that a route commonly followed looks much like mowing grass, going backwards and forwards in a linear fashion progressing through the space that needs to covered. But he explained that if speed is the most important factor “then you'll just maybe touch the edges” of the previously completed line, “but if you really want high probability of clearance, then you might overlay by 50 percent.” The system has up to 200m of length behind it knowing when and how to make turns.

The Thales SAMDIS is multi-aspect, so that during a sweep it can take picture of the targets at 30 degrees forward, 90 degrees to the side and 30 degrees to the rear. It repeats this from the other side on its return route, offering much more data to identify and classify an object than was previously available.

The USVs have servers on board that can manage the huge amounts of data collected, estimated at about one Terabyte per mission each day. This can escalate into Petabytes across multiple days. The data is sent back to the POC in real-time for analysis where artificial intelligence (AI) software will put it through a threat library. “It is about operators making informed decisions supported by autonomy,” Hunt said. This is what enables the system to cover an area four times faster than using legacy MCM systems.

Once a mine is detected the USV will continue its route without stopping. The location data for the target will allow for a second USV with neutralisation equipment to engage, or for the same USV rerolled to return later to the site. The USV will autonomously deploy the Double Eagle MuMNS ROV, which can confirm the target with its camera sensors and place a charge on the mine – it can do this up to three times – all of which is controlled by the POC.

In the UK, MHC Block 1 also includes the delivery of five mine sweeping system from Atlas Elektronik UK that use an 11m-long USV called the Atlas Remote Combined Influence Minesweeping System (ARCIMS), named as RNMB Hussar by the RN. ARCIMS is fitted with acoustic, electronic, and magnetic payloads that can emit signals through a towed craft to trigger mines into thinking that a target ship is passing by.

The first four USVs, named RNMB Hussar, Halcyon, Harrier, and Hazard have been delivered with a fifth ordered by the MoD in January 2022. The final USV will be named Hydra and is expected to arrive by the end of 2022. These are known as the Combined Influence Sweeping (CIS). The sweeping systems are deployable by Royal Air Force Boeing C-17 and Airbus A400M transport aircraft. France is not receiving a CIS system under SLAM-F.

Both France and the UK will make a decision about proceeding to MHC Block 2, which will procure the bulk of the systems, after successfully achieving an initial operating capability (IOC) in 2024. The RN wants its systems to enter service by the time the RN’s last six Hunt-class MCMVs leave service from 2029-31.

As a part of SLAM-F France has also received three A27-M AUVs from ECA as part of its demonstrator project and it will also replace its existing 10 Éridan-class (Tripartite) mine hunter vessels with between 4-6 new 2,800 ton mine warfare mother ships.

Wider Appeal

ECA has formed a joint venture with Naval Group to form the Belgium Naval & Robotics consortium, which is delivering 12 MCMVs to the Belgian and Netherlands navies under the rMCM project from 2024-2030 as well as a MCM solution for a total of $2.1 billion. An agreement was signed between the two countries in November 2016 that will see Belgium lead the MCM and toolbox acquisition with the Netherlands leading on a future frigate project. The 12 vessels will replace both navies’ existing 11 Tripartite MCMVs and a Belgian support ship. Built by Kership (a joint venture between Naval Group and Piriou) the first new MCM mother ship will be delivered in 2024.

Meanwhile ECA is delivering the MCM toolbox that includes the Inspector 125-M and 125-S USVs, A-18M AUV and T-18M towed SAS as well as the Seascan Mk2 ROV and K-ster C mine neutraliser.

The 125-M is capable of carrying and deploying a variety of mine hunting payloads including towed sonar, AUVs and mine identification and destruction equipment. The 125-S is dedicated to the sweeping role using the MLM-3100 magnetic influence system from CTM and Patria's ACS-66 acoustic generator. The A18-M is fitted with the UMISAS synthetic aperture sonar; and Saab is providing its V-200 Skeldar UAS to watch for mines on the surface. All these systems are managed using ECA’s UMISOFT software.

ECA’s Giannoni said: “We see the potential for developing even further beyond what is already being developed, which is unprecedented in the MCM domain –having an USV deploying and recovering an AUV by itself, and the AUV equipped with a SAS with a high level of performance able to adapt its own mission depending on what the sonar is seeing. We are not going to stop there.”

More Use Of Drones

In the future he expects the increased use of drones of different types to extend the duration of operations; an enhancement in sensor performance and more autonomous decision-making and data processing at the edge to speed up missions; simulation systems that better represent the water column and environment to train operators and the systems in advance to prepare the autonomous capability to face what they find in a minefield; and that MCM missions will become a more integrated part of larger missions such as surveying, seabed warfare and rapid environmental assessment among others.

Elsewhere the US Navy is introducing its new Unmanned Influence Sweep System (UISS) onto its Littoral Combat Ships (LCS). The system uses a 12m-long MCM USV that deploys the Mk104 acoustic generator and magnetic cable for minesweeping. Textron Systems was awarded a contract in 2014 to provide the UISS, which achieved IOC in July 2022. The MCM USV also operates a mine hunting and neutralisation payload that will replace the USN’s existing MCM-1 Avenger-class MCMVs and Sikorsky MH-53 Sea Dragon MCM helicopters.

David Phillips, senior vice president of Land and Sea Systems at Textron Systems told Armada: “IOC for the UISS was a huge achievement. The Navy/industry team is wrapping-up efforts to complete operational testing of the Mine Hunt payload that is also part of the mine countermeasures mission package. Once complete, the Navy will have both unmanned mine sweeping and mine hunting capabilities that can be deployed on Littoral Combat Ships.”

Thales’ Hunt said that MCM technology investment for the future include eco-options, which are becoming more important for navies and delivering towards net-zero. This includes electric propulsion, hydrogen fuel cells, novel additive manufacturing techniques and use of 3D printing. To counter future threats MCM capabilities will go “further, deeper, faster and more stealthy,” Hunt concluded.