Visby Class

The design of the Visby has been directed to minimising the optical and infra-red signature, above water acoustic and hydroacoustic signature, underwater electrical potential and magnetic signature, pressure signature, radar cross section and actively emitted signals. A stealth corvette of the YS 2000 design has a detection range of 13km in rough seas and 22km in calm sea without jamming. In a jammed environment, the Visby would be detected at a range of 8km in rough sea and 11km in calm sea. The hull material is a sandwich construction comprising a PVC core with a carbon fibre and vinyl laminate. The material provides high strength and rigidity, low weight, good shock resistance, low radar and magnetic signature.

COMMAND AND CONTROL The vessel's CETRIS C3 (command, control and communications) system consists of the SaabTech Vectronics (formerly CelsiusTech) 9LV Mk3E combat management system, the MAST decision support aid and the integrated communications system. The 9LV Mk 3 is based on open system architecture and uses the Windows NT operating system. The SaabTech CEROS 200 radar and optronic fire control system has been ordered for the Visby and will be fully integrated into the combat management system. The communications system has a high capacity digital communications switch, developed by Danish company Maersk Data Defence (formerly Infocom) together with Karlskrona, which interconnects the voice and data communications channels. The system provides internal communications or open conference lines and access to external communications with various radio links and land-based networks.

MISSILES Visby vessels will not initially be fitted with an air defence missile system, but could later be equipped with one, such as the Saab Bofors Dynamics Rb23 BAMSEA or Raytheon Evolved Seasparrow Missile. The corvettes will be equipped with eight Saab Bofors Dynamics RBS 15 anti-ship missiles. The missiles will be installed below deck and be fired through special hatches to maintain the vessel's stealth. The missile's exhaust plumes will be managed in separate canals. ANTI-SUBMARINE WARFARE The Visby is equipped with a suite of ASW 127mm rocket powered grenade launchers, depth charges and torpedoes. There are three fixed 400mm torpedo tubes for Tp 45 anti-submarine homing torpedoes. Saab Dynamics are developing the ALECTO multi-mission launcher to equip the Visby Class. The launcher will be able to dispense ASW weapons, torpedo countermeasures and chaff and infrared decoy rounds.

GUN The Visby is equipped with a Bofors 57mm 70 SAK Mark III general purpose gun. The gun has a fully automatic loading system containing 120 rounds of ready-to-fire ammunition. The gun fires up to 220 rounds/minute to a maximum range of 17,000m. MINE COUNTERMEASURES (MCM) The Visby will carry Saab Bofors Underwater system ROVs (Remotely Operated Vehicles) for mine hunting and the STN Atlas Elektronik Seafox ROV for mine disposal. The minehunting ROVs are a development of the Double Eagle Mk III. The Visby corvettes will be fitted with the Hydra multi-sonar suite from Computing Devices Canada (CDC), which integrates data from a passive towed array sonar, dual frequency active variable depth sonar (VDS), hull-mounted sonar and the ROVs.

SENSORS Ericsson's Sea Giraffe AMB 3D C-band multi-role radar provides air and surface surveillance and tracking and target indication to weapon systems. It features 3D agile multi-beam technology and can handle multiple threats up to 20,000m (65,000ft) at elevations up to 70�. ECCM (electronic counter countermeasures) capabilities include ultra-low antenna sidelobes and both frequency and code agility. The antenna has a rotation rate of 30rpm for surveillance and 60rpm for air defence. There is also an I-band surface search and I/J band fire control radar.

COUNTERMEASURES The CS-3701 Tactical Radar Surveillance System (TRSS) from EDO Reconnaissance & Surveillance Systems provides Electronic Support Measures (ESM) and Radar Warning Receiver (RWR) functions.

PROPULSION The Visby is equipped with a combined diesel and gas (CODAG) turbine arrangement. Four TF 50 A gas turbines from Honeywell and two MTU 16V 2000 N90 diesel motors are connected to two gearboxes which run two Kamewa waterjet propulsors. The motors provide a maximum speed of 15 knots for long duration and 35 knots for short duration. The ship has rudders and bowthrusters for harbour manoeuvring.

Speficiations :
Crew: 43
Length: 72 meters
Length between perpendiculars: 61.5 meters
Width: 10.4 meters
Draught: 2.4 meters
Displacement, full load: 600 tons
Hull Design: FRP sandwich
Speed: 35 knots
Propulsion: 2 waterjet propulsors
Generators: 3 generators(diesel), 810 total kW

Price: 60 million

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