By Luca Peruzzi
At Seafuture 2021 Ferretti Security and Defence (FSD), a Ferretti Group division, exhibited the hybrid powered version of its FDS 800 patrol boat, in service with Italian Carabinieri, together with other high-speed platform solutions.
In June 2019, FSD was selected and a contract was awarded for the delivery of 16 N800s, as the new type of fast patrol boats was designated by the Carabinieri, the Italian police corps with military status that although depending from the Ministry of Defence operates mostly under the Ministry of Interior. The N800, which will replace the Class 800 patrol boats currently in service, is build according to RiNaMil Fast Patrol Vessels Rules, Military Police notation, and can withstand Sea State 4. With a length of 16.75 meters, a beam of 4.43 meters and a 1.57 meters draft, the N800 class boats are built with a composite materiel hull made of glass-carbon fibre. With a full load displacement of 25.5 tonnes, the N800 has a crew of 3+3. In its hybrid-propulsion version the N800 is powered by two MAN i6 diesel engines providing 800 hp each at 2,300 rpm, fitted with V-drive reduction gears, moving two 65 mm diameter shaft and two five-blade fixed pitch 965 mm diameter propellers, allowing for a requested maximum speed of over 30 knots at full load and an endurance of over 300 nm at 22 knots cruise speed. In addition to the crew, the N800 can host up to 12 persons and is equipped with a 3.8 meters inflatable dinghy, which an outboard 9.9 hp two-stroke engine, is hosted in the engines’ bay.
In order to carry out law enforcement operations in marine protected areas with minimal impact, the Carabinieri opted for a number of platforms to be equipped with a hybrid propulsion package, the first being unveiled during Seafuture 2021. These boats are equipped with a new concept Transfluid diesel/electric hybrid propulsion that allows a “zero emissions” navigation.
The system, which was unveiled to EDR On-Line during the exhibition consists of two three-phase electric motors with permanent magnets each delivering 75 kW, mounted between the diesel engines and the shaft lines, and two latest generation battery packs with lithium-iron phosphate cells, each one providing 288V 100Ah, all managed by an integrated monitoring system. Beside the propulsion line lay-out modification, the insertion of the 75 kW motors brought to a complete redesign of electric and cooling plants: the latter maintains the air cooling for thermal engines, while electric ones are water cooled, direct cooling being provided by a fresh water system, which is cooled by a seawater system through a heat exchanger.
The hybrid version is equipped with two add-on displays on the pilot’s console, one right and one left of the main screen; these provide information on electric motors and battery status, a different set of engine throttles integrating electric motors controls replacing standard ones.
The boat seen at the exhibition was the second of class, but the first to be equipped with the hybrid propulsion the first one featuring a standard diesel propulsion. The hybrid propulsion N800 was delivered to the Carabinieri Naval Service in June 2020 and was operationally tested in different environments, being assigned initially to the Lipari Naval Station in the Eolie islands archipelago, and then to the Civitavecchia naval station, near Rome. During the service, in addition to the platform performances and seakeeping, the FSD N800 already demonstrated to be capable to sail under all-electric propulsion for one hour at 7 knots or two hours at 5 knots.
Photos by Luca Peruzzi