Developed as a fibre-optic wire-guided acoustic homing heavy-weight torpedo designed to neutralise enemy ships and submarines for Marine Nationale (French Navy), the Naval Group (former DCNS) F21 Artémis Torpedo programme is projected to replace the existing F17 torpedo with a new generation more agile, faster, smarter and more operational performance torpedo. As the only new heavy torpedo development in the world, the characteristics of F21 are significantly superior to all other heavy torpedoes currently in service. With an exceptional range and speed, the F21 torpedo is planned to evolve by sea bottom but also and especially in the very noisy and very dense coastal/littoral areas in maritime traffic. Equipped with a complete “sonar suite” and an advanced mission system both with extremely high computing power allowing real-time combined complex signal and data processing, the F21 torpedo maintains a clear tactical picture even in the most confined coastal areas and against the most sophisticated torpedo defence systems. Whatever the operational sequence (search/pursuit/attack), the F21 benefits from a high level of discrimination, identification, Acoustic Counter-Counter-Measures (ACCM) and homing.
The contract includes the development and delivery of about one hundred F21 torpedoes and their integration into French submarines (all six Barracuda Class nuclear powered attack submarines/SSN, some of the Rubis Class SSN, all four Le Triomphant Class nuclear powered ballistic missile submarines/SSBN and the future 3rd generation SSBNs or SNLE3G). It has also been selected for the Brazilian Navy, and proposed for Indian Navy (IN) Scorpène/Kalvari Class diesel-electric hunter-killer submarines (SSK).
Initially F21 was proposed to be a development version of the Italian Black Shark torpedo to be built by a joint venture between DCNS, Thales and WASS. However Naval Group developed the F21 Artemis with Thales and Atlas Elektronik. Still, similarities with the Black Shark include an electric motor driven by an aluminium silver-oxide (AgO-Al) battery. The new generation of silver oxide-aluminium (AgO-Al) sea-water primary battery use dissolved sodium dioxide powder as electrolyte and incorporate a new electronic closed loop electrolyte circulation system. The battery delivers power and energy independently of the depth. In comparison with silver-zinc and other technologies, AgO-Al energy density is unrivalled. It ensures both maximum speed beyond 50 knots (93km/h) and endurance around 1 hour without compromising safety. The AgO-Al primary battery electrolyte only starts once sea water enters the battery section, which is impossible as long as the torpedo is in the submarine’s tube, preventing any unexpected electrolyte triggering on board. In addition, the F21 features a B2211D insensitive explosive warhead and a fully electronic fuse which fulfills not only Insensitive Munition (IM) STANAG 4439 and 4187 standards but also the numerous additional French Navy requirements for SSN and SSBN weapon integration. This results in IM signature being validated at torpedo level by the French assignment authority. Launched in swim-out mode, F21 sports a range of 57 km and can attain a maximum depth of 600 m.
The advanced sonar and mission system associated with unmatched vehicle capability such as endurance, engagement distance, minimum and maximum speed, silent electric propulsion, wake homing and fibre-optic wire guidance widen significantly the F21 operational employment in times of both war and crisis. The 250 kg warhead, which is detonated either on impact or on acoustic triggering, makes the F21 capable of destroying any submarine or any surface vessel including those with unconventional hulls.
MIGAL fire control system serves as the interface between the torpedo and the submarine’s combat information centre. The MIGAL’s prime function is to control the torpedo firing sequence for combat and training launchings. The MIGAL presets, checks, launches and wire-guides the F21 and other available torpedoes, one at a time or in salvoes (up to 4 HWT on four targets). The user friendly Man-Machine Interface is available either in stand-alone mode or through the combat management system. The MIGAL is compatible with any heavyweight torpedo and can be installed on board any submarine or surface vessel. A navy can thus deploy different types of torpedoes from the same platform which in turn helps it to switch smoothly from one torpedo type to another. Today more than 40 MIGAL systems equip six navies.
Sayan Majumdar