Fincantieri takes a model of the S800 Light Submarine at IDEX/NAVDEX 2023

Luca Peruzzi

Among the models of naval platforms being presented at NAVDEX 2023, Fincantieri is exhibiting the S800 Light Submarine. The fact that the Italian shipbuilder has been showing the model for the first time in the Middle East, could be interpreted as an indication of the raising interest toward small and compact manned and unmanned combatant platforms in the region, although Fincantieri hasn’t commented and/or confirmed any programme in the same region. In a cyclical way such interest also surfaced in the past. In terms of platform and combat system readiness, the Italian shipbuilder mentioned to EDR On-Line a state of development compared to a post critical designed review (CDR) milestone.

The S800 has been developed to meet all main requirements for mission in the littoral environment, and at the same time provide comparable performance of conventional submarines operating in blue waters to more than 250 meters depth.

Conceived on the basis of concepts, experiences and technologies developed with the U212 and U212NFS programmes, and smaller platforms envisaged by Fincantieri in order to operate in shallow waters, the S800 Light Submarine is characterized by a compact design with an overall length of 51 meters, a pressure hull diameter of 4.80 meters and a total height (including mast) of 10 meters, alongside an automated platform control system with four ‘X’ stern rudders and forward hull-positioned hydroplanes, enabling the submarine to perform very tight maneuvers and follow the sea bottom contour.

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With a surfaced (ready to dive) and submerged displacement of respectively 750 and 850 tonnes, the S800 Light Submarine is characterized by a diesel-electric with AIP (Air Independent Propulsion) propulsion system featuring a 12-cylinders turbocharged V-batt diesel engine with synchronous generator, and a permanent magnet excitation electric motor driving a propeller group with a 3 meters diameter, and two batteries banks, alongside two Fuel Cells Modules with a maximum output power of 70 kWe each.

According to Fincantieri the introduction of an AIP plant on small underwater platforms allows a ‘very high submerged endurance’ by means of conventional diesel-electric propulsion, as well as reducing to zero the indiscretion ratio; the estimated endurance is seven days of submerged patrol, while at the same time the extremely quiet operation of the Fuel Cells system guarantees keeping the acoustic signature at minimum.

A very low signature was reached by the optimization of the acoustic and non-acoustic signature to avoid ASW detection. With an operational depth of 250 meters and a maximum submerged speed of over 15 knots, the underwater endurance on batteries at 4.5 knots and AIP at the same operating speed is indicated respectively in over 200 and 700 nm, while autonomy reaches the 4,500 nm with snorkel and batteries, and overall endurance is respectively of 30 and approximately 7 days, in the latter case with AIP.

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With a crew of 18 among officers and crew and the capability to carry a team of eight SOF operators, the S800 is being promoted by Fincantieri with a combat system based on four multifunctional consoles (three devoted to the combat system and one to the platform control) and a sonar suite including a passive flank array sonar, a passive cylindrical array sonar, an active array, an active obstacle avoidance sonar, alongside a passive cylindrical intercept array sonar. The sensors suite also includes an attack periscope, a search optronic mast, communications and navigation radar masts, an EW suite with a RESM antenna on periscope, as well as an underwater telephone, alongside torpedo countermeasures system.

With a five swim-out pneumatic torpedo tubes, the S800 Light Submarine weapons load consists of five heavy-weight torpedoes in the launchers, and four plus one in the torpedo room, allowing a maximum inventory of nine (plus one) weapons. The latter are expected being Leonardo Black Shark Advanced (BSA) heavyweight torpedoes.

Thanks to its size and hull characteristics the S800 is the operationally most suitable strategic asset for supporting Special Forces missions, providing the capability to release and recovery two chariots in fully covert operations, according to Fincantieri.

Phots courtesy L. Peruzzi – Image courtesy Fincantieri