Acknowledged leaders in mine warfare, the French Navy and its contractors are pioneering the development of offboard robotic solutions to keep personnel out of harm’s way.
The latest concepts are designed around a mother ship deploying various drones, each performing a specific function. For mine detection and location, the ship deploys a launch-like uncrewed surface vehicle with a towed sonar and smaller autonomous underwater vehicles also equipped with sonars. The capabilities of the USV and AUVs are complementary. The USV is faster and remains in contact with the control station on the mother ship (or on shore) while the AUVs go deeper, but can only relay data by returning to the surface.
If a mine is detected, the ship deploys a second USV, this time equipped with an ROV instead of the towed sonar. The tethered ROV’s job is to accurately identify the threat then place an explosive charge to destroy it.
In 2016, following a series of experiments, France and the UK launched the MMCM programme, led by prime contractor Thales in both countries. The aim is to replace conventional French and British minehunters by autonomous stand-off systems. By early 2020, the contractors aim to have qualified two systems, one in each country.
Thales has developed and tested (sea trials began in 2018) a USV based on the Halcyon demonstrator developed by British contractor ASV. Optimised for mine warfare, this 12m drone has a shock-resistant composite hull and low observables. It deploys a T-SAM towed sonar with a Samdis high-resolution synthetic aperture array and can dive to a depth of 80m.
For mine identification and clearance, the USV deploys a dedicated ROV, namely the MuMNS multi-shot mine neutralisation system developed by Saab of Sweden which can destroy up to three mines per sortie.
The MMCM system also uses type A27 AUVs (5m x about 70cm) developed by French company ECA. Deployed by the mother ship (or from the shore), these detection and classification AUVs work in conjunction with the USV and its towed sonar. Each AUV is equipped with a sonar, also using the Samdis synthetic aperture array, and can dive to 300m. Depending on the seafloor relief, the towed sonar and the AUVs can work together to explore a larger area or else independently.
All three types of drones (USV, ROV and type A27 AUVs) have very low observables (i.e. acoustic, electric and magnetic signatures) to avoid them from being seen by a mine as a threat. Each can be remotely controlled by an operator or preprogrammed to execute a mission profile including actions to be taken in response to any objects or obstacles encountered. Data gathered by each drone are relayed to the mother ship (or a shore command centre). Where necessary, data can be relayed by a UAS using ultrasecure links. The MMCM multi-console control station uses an AI-based management system. It fits into a standard container and is air-transportable.
In parallel with the MMCM programme, France will finalise the specs for its MCM mother ships in 2019.
More information in Mer et Marine Euronaval 2018 Special issue : "Naval Forces : focus on french technology"