A boatload of expertise


The late 1800s saw the arrival of the first torpedo boats and military submarines. Naval Group’ experience in submarines dates back to this era, with the launch in 1863 of Le Plongeur, the world’s first motorized submarine. It was followed by Le Gymnote in 1886, one of the world’s first diesel-electric submarines, and Le Narval in 1899, the world’s first operational torpedo-carrying submarine. Both were built in shipyards that are now part of Naval Group.

Fast forward to 2016. Naval Group is one of the few companies in the world to have design competencies in nuclear and conventional submarines, having safely delivered 37 submarines, ranging from 2,000 tonnes to 14,000 tonnes, in the past 50 years. Naval Group currently designs, builds and/or maintains Scorpène® 2000 submarines for Brazil, Malaysia, India and Chile. Naval Group is designing and building the new Barracuda SSN attack submarine for the French Navy, the first of which will enter service in 2017. Naval group is also responsible for France’s current fleet of Le Triomphant-class SSBN submarines.

Discover how Naval Group overcomes some of the deepest challenges of submarine design and construction.


Challenge #1: Designing under pressure

Ever since it was invented, the submarine has been one of the most complex kinds of vessels ever built by humankind. The hull must withstand extreme external pressure. Weight and balance need to be precisely calculated. Crew and equipment must fit within a confined space. Depending on the role for which it is designed, the submarine must be able to operate at a wide range of depths, from shallow to deep waters, and meet a variety of requirements for stealth, shock resistance, electrical efficiency, weapons load, mission, maintenance, etc.

Challenge #2: Airless propulsion

Compared to their nuclear-powered counterparts, conventional-propulsion submarines have historically been limited in their underwater endurance. Because their diesel engines need oxygen to operate, they switch over to battery power when fully submerged and must regularly surface to recharge. Naval Group offers a range of solutions to increase submerged autonomy. These range from lithium-ion batteries, which can increase underwater endurance of a Scorpène®-type submarine to seven days, to a second-generation, fuel-cell air-independent propulsion system (AIP) that stretches endurance to three weeks.

Challenge #3: Eyes and ears

While stealth is a submarine’s main strength, its biggest weakness has always been situational awareness. That’s why Naval Group’ thinking about submarines has always looked beyond sonar and periscopes. It has developed solutions like the Vipère® multifunction buoy that enhances a submarine’s intelligence-gathering and communications capabilities without having to come up to periscope depth. Other solutions include unmanned underwater and air vehicles (UUVs and UAVs) that can roam far from the submarine’s location.


Challenge #4: Packing a punch

Whether used for attack or missile launches, submarines need a fully integrated combat system to gather information, build a comprehensive picture of the tactical situation and deploy weaponry. The combat system also needs to include a weapon handling and launching system. In addition to building submarines and SUBTICS®, a combat system that has been fitted in 42 submarines worldwide, Naval Group also designs and makes its own torpedoes, including the F21 heavyweight, dual-purpose torpedo used by the French Navy.


Challenge #5: Quiet, please

With its experience building nuclear deterrent and attack submarines, Naval Group has acquired extensive expertise in stealth design. Thanks to decades of R&D and real-world experience, it is able to reduce the acoustic signature of its submarines by mitigating mechanical and hydrodynamic noises. Advanced materials, propeller design, sound insulation, vibration reduction, AIP systems and optimized crew sizes also help increase the boat’s stealth.