Thales to supply new generation sonar for France's SNLE 3G submarine

According to a PR published by Thales on July 11, 2023, the French defence procurement agency, DGA, has given Thales a contract to upgrade sonar suites on its third-generation nuclear-powered ballistic-missile submarines (SNLE 3G), as well as modernize those of its second-generation fleet (SNLE 2G).
Follow Navy Recognition on Google News at this link

Russian Vyborg Shipyard laid the Purga ice class coastguard ship of project 23550 925 001 Artist rendering of the third-generation nuclear-powered ballistic-missile submarine. (Picture source: Naval Group)

This upgrade will see the implementation of revolutionary technology, including large sensor arrays backed by robust Big Data algorithms. These enhancements aim to provide an extensive understanding of the underwater acoustic environment to counter ever-evolving covert threats for future generations.

The contract underlines the continued faith the French Ministry of the Armed Forces places in Thales in preserving the French Navy's underwater detection supremacy.

The improved sonar suite from Thales will have the capability to detect, pinpoint, and categorize threats across a wide range, facilitating unprecedented underwater situational awareness.

Submarines, which form a crucial strategic component of naval forces faced with an increasing variety of threats, will greatly benefit from this upgrade. The French Navy's Strategic Oceanic Force (FOST) currently employs four such SSBNs as a consistent nuclear deterrent.

The DGA contract encompasses the conceptualization and creation of the sonar suite for third-generation SSBNs, and the precise design and implementation for second-generation vessels.

The innovative technologies from Thales will affirm the acoustic dominance of France's submarines in the future. Large-scale arrays comprising multiple sensors will offer an unparalleled level of threat detection accuracy.

Moreover, the advanced sensors will produce significantly more data compared to previous systems. The ALICIA data processing system will utilize state-of-the-art Big Data algorithms, with user-friendly interfaces designed to lessen operator workload and assist in decision-making. This reflects the increasing application of sophisticated data analytics and machine learning algorithms in contemporary defence strategies.


With a displacement of 15,000 tons when submerged and a length of about 150 m (490 ft), the new class of submarines stands ready to replace the Triomphant class around 2035.

The SNLE 3G showcases power with a 220 MW (300,000 hp) installation, and its propulsion system is centered around a K22 pressurized water reactor. This allows the SNLE 3G an unlimited distance range, and it is designed to run for 20–25 years without needing refuelling. The vessel could serve until 2090.

The submarine's armament is as imposing as her size. Nuclear-armed, it houses 16 M51 missiles each carrying six to ten TNO 100kt thermonuclear warheads. Furthermore, she accommodates 533 mm (21 in) torpedo tubes compatible with F21 torpedoes and anti-ship missiles.