Underwater weapons serving naval superiority

Together with the French Navy, the French Defence Procurement Agency (DGA) – the project owner for defence programs – and its industrial partners, naval group has developed product ranges designed to address both current and future threats. With forty nations operating submarines, several hundred submarines are currently deployed across the world’s seas and oceans. This growing level of underwater activity is further intensified by the increasing stealth of vessels and the rapid emergence of drones.

“Actions are becoming harder and harder to distinguish, and intentions are less and less explicit, often revealed only at the last moment,” explains Yann. Faced with this constantly evolving threat, underwater weapons provide nations with essential tools for controlling their maritime domains, and ultimately safeguarding their sovereignty. As a concentration of technology, modern torpedoes can now be launched tens of kilometres from their host platform, operating autonomously through acoustic guidance or fibre-optic guidance. Thanks to onboard intelligence, the underwater environment is continuously analysed to adjust the trajectory in real time without human intervention. Some torpedoes are therefore capable of evading defences or countermeasures deployed by adversaries. This approach keeps the human operator in the decision loop while greatly enhancing adaptability.

A historic expertise

The MU90 and the F21® are the two types of torpedoes operated by the French Navy. Originally developed as part of Franco-Italian cooperation, the MU90 is a lightweight torpedo deployed from surface ships and aircraft. The F21® heavy torpedo, meanwhile, equips submarines.

Both torpedoes are produced, in whole or in part, by Naval Group at its Saint-Tropez site. More than a century of experience has made Naval Group’s Drones, Autonomous Systems and Underwater Weapons Department a centre of excellence in the manufacture of torpedoes, torpedo countermeasures and underwater drones.

“A torpedo concentrates the most advanced technologies mastered by the group and deployed across our naval programs in a compact format. Our systems and equipment benefit from the most advanced technological building blocks available,” explains Jérôme Brocq.

MU90:  a high-performance light-weight torpedo

The MU90, a third-generation lightweight torpedo, was designed to neutralise both conventionally powered and nuclear-powered submarines. “The MU90 has successfully adapted to targets that are more numerous, smaller and more agile. Whether in terms of endurance or its ability to detect and engage its target, it remains a benchmark on the market,” explains Bertrand Gaillardin. “The contracting of modernisation work and the launch of production of new torpedoes are scheduled for 2026, with a major challenge in restarting the production line,” adds Lionel.

ReadMU9O: performance, adaptability, maturity

F21®: an adaptable and combat-proven heavy-weight torpedo

Developed to equip the Barracuda-program nuclear attack submarines (SSNs), the F21® heavy torpedo entered service in 2020 aboard the Suffren. It has since been integrated across Suffren-class and Rubis-class SSNs, ballistic missile submarines (SSBNs) and Brazilian Navy Scorpène®-class submarines. Its mission: the neutralisation or destruction of underwater and surface targets, many of which are equipped with sophisticated detection systems and torpedo countermeasures. “The F21® was developed through an incremental approach that allows the integration of the latest technologies while maintaining the highest safety standards, essential for equipment deployed on nuclear-powered submarines,” says Jérôme Brocq. “Its hunting capabilities, speed, discretion and long-range fibre-optic guidance make the F21® one of the most capable torpedoes on the market. The fact that it is ‘French sea-proven’ is a mark of confidence for foreign navies,” adds Yann. A new version of the torpedo, known as the Mk2, is currently in the development and qualification phase.

F21®: reliability, intelligence, safety

Canto®: a revolutionary torpedo defence system

Drawing on its expertise in torpedoes, Naval Group has developed Canto®, a torpedo countermeasure designed to protect submarines and surface ships from the most advanced torpedoes. Based on the principle of acoustic dilution and confusion, Canto® generates a powerful 360-degree acoustic signal covering the full range of frequencies used by enemy torpedoes. “Our expertise in underwater weapons has enabled us to develop the most effective solution to counter them,” says Bertrand Gaillardin. More than 500 units have already been delivered to customer navies, with 600 additional units scheduled for delivery in the coming years.

Maintenance and training: a multifaceted collaboration

Naval Group is also responsible for the in-service support (ISS) of torpedoes and torpedo countermeasures, as well as for crew training. This work is carried out in close coordination with the DGA and, for ISS activities, with the French Joint Munitions Service (SIMu), which manages ammunition availability for the armed forces. “Torpedoes undergo a regular maintenance cycle. Close dialogue between all stakeholders is essential to manage this ISS effectively – the objective is to ensure torpedoes remain in perfect working condition while maintaining fleet availability,” explains Lionel. At the Naval Group site in Saint-Tropez, exercise torpedoes are prepared and crews are trained in their operational use. “The advantage of torpedoes is that tests can be carried out without a warhead and the torpedo can be recovered afterwards. This generates extremely valuable feedback on the weapon’s behaviour at sea,” adds Yann.

Preparing the underwater weapons of tomorrow

“Because an incremental approach enables innovation to be integrated more quickly, the DGA is already preparing the next evolution of the F21® as part of the defence technologies project (PTD). Discussions are currently under way, particularly around emerging technologies that could enhance both the acoustic head and the weapon’s intelligence,” says Yann. All this work is carried out in close collaboration with the French Navy in order to define future operational needs. Finally, to meet both current and future requirements from naval customers – particularly regarding the armament of light platforms such as naval drones and counter-drone warfare – Naval Group is conducting self-funded R&D on a range of very lightweight underwater weapons, with trials scheduled to take place later this year.