Nansen Class Anti-Submarine Warfare Frigates, Norway

The five Nansen Class anti-submarine warfare frigates were built by Navantia of Spain for the Norwegian Navy. The vessels are: HNoMS Fridtjof Nansen (F 310), Roald Amundsen (F 311), Otto Sverdrup (F 312), Helge Ingstad (F 313) and Thor Heyerdahl (F 314).

HNoMS Fridtjof Nansen (F 310) 

The first vessel was launched from Navantia’s Ferrol shipyard in June 2004. Sea trials of the Nansen with the Aegis weapon system and the new SPY-1F radar began in October 2005. The Nansen was commissioned in Ferrol in April 2006 and arrived in Oslo, Norway in June 2006.

Launch of the second, Roald Amundsen, was in May 2005 and it was commissioned in May 2007. The Otto Sverdrup (F 312) was launched in May 2006 and commissioned in April 2008. Helge Ingstad (F 313) was launched in November 2007 and commissioned in September 2009.

Helge Ingstad (F 313) 

The last ship, Thor Heyerdahl (F 314), was launched in February 2009 and commissioned in January 2011. The Nansen Class replace Oslo Class vessels in service since 1966.

The main contractor is Navantia (formerly Izar) of Spain and the Aegis weapon systems integrator is the US company, Lockheed Martin. The vessels are of modular construction and the completion of the first module of the hull (‘keel-stretching’) of the Fridtjof Nansen took place in April 2003. Lockheed Martin delivered the first Aegis system in December 2003.

List of ships

Fridtjof Nansen class — significant dates
Pennant number Name Ordered Laid down Launched Commissioned
F310 Fridtjof Nansen 23 June 2000 9 April 2003 3 June 2004 5 April 2006
F311 Roald Amundsen 23 June 2000 3 June 2004 25 May 2005 21 May 2007[8]
F312 Otto Sverdrup 23 June 2000 25 May 2005 28 April 2006 30 April 2008[9]
F313 Helge Ingstad 23 June 2000 28 April 2006 23 November 2007 29 September 2009
F314 Thor Heyerdahl 23 June 2000 23 November 2007 11 February 2009 18 January 2011


The main mission of the frigate is anti-submarine warfare and the ship is equipped to detect, identify, track, engage and attack hostile submarines.

The ship is also equipped for anti-air warfare and anti-surface warfare roles and can carry out non-combatant tasks in peacetime. The ship houses a medical facility.

Nansen Class frigate design

The 4,600t ship has five decks and two superstructures. The welded steel, 132m monohull has 13 watertight compartments for enhanced survivability. The hull design is optimised for stability, sea-keeping and manoeuvrability and the hull appendages and propellers are designed for low hydrodynamic noise.

NH90 ASW helicopter – NavantiaOficial

The ship has a helicopter landing deck and hangar which can support one medium-sized helicopter. Six AgustaWestland Lynx helicopters operated by the Norwegian Air Force are to be replaced by the NH Industries NH90 ASW helicopter on order for the Royal Norwegian Navy.

Roald Amundsen (F 311) – Image

The NH90, to be deployed on the Nansen frigates, will have Thales Underwater Systems’ flash sonics dipping sonar system and anti-submarine torpedoes.

AEGIS command and control combat aircraft – – – – NavantiaOficial

The integrated weapons system from Lockheed Martin is based on the Aegis combat system from Lockheed Martin and anti surface and MSI 2005F anti-submarine warfare systems from Kongsberg Defence and Aerospace.

Kongsberg MSI 2005F ASW combat system

Kongsberg MSI 2005F ASW combat system – Image

Fridtjof Nansen class frigates for the Royal Norwegian Navy KONGSBERG is responsible for the Anti-Submarine Warfare (ASW), Anti Surface Warfare (ASuW) and the Integrated Bridge/Navigation Systems on the new Fridtjof Nansen class frigates. These sub-systems have been integrated into a modern, modular, COTS-based Combat Management System, which can easily be adopted to other classes of surface combatants. Source

The Aegis combat system for the Nansen is based on the Spy-1F multifunction phased array radar, a scaled version of the AN/SPY-1D in service on US Navy Aegis cruisers and destroyers. It provides missile and gun fire control functions, simultaneous multiple target tracking, volume radar search and horizon search.

The phased array radar provides instantaneous beam steering which gives the advantage of vast reaction time against airborne threats.

Spy-1F multifunction phased array radar


General data:
Type: Radar Altitude Max: 60960 m
Range Max: 324.1 km Altitude Min: 0 m
Range Min: 1.1 km Generation: Early 2000s
Properties: Identification Friend or Foe (IFF) [Side Info], Non-Coperative Target Recognition (NCTR) – Jet Engine Modulation [Class Info], Continous Tracking Capability [Phased Array Radar], Track While Scan (TWS), Moving Target Indicator (MTI), Pulse Doppler Radar (Full LDSD Capability)
Sensors / EW:
Role: Radar, FCR, Surface-to-Air, Long-Range
Max Range: 324.1 km

RSR 210N multipurpose 2D radar system


Reutech RSR 210N is a lightweight X-Band 2D naval air/sea surveillance radar designed for application on smaller naval and coastguard vessels. This radar, which provides coverage to beyond 50 km, may be supplied with a dedicated console or may be interfaced to a Combat Management System. Whilst it is particularly suited to helicopter support operations aboard ship, it is also applied in a general surveillance and gunfire support role. The technology applied in this system is derived from the RTS 6400 tracking radar currently in service with the SA Navy. Source

General data:
Type: Radar Altitude Max: 1981 m
Range Max: 55.6 km Altitude Min: 0 m
Range Min: 0.4 km Generation: Early 2000s
Properties: Pulse Doppler Radar (Full LDSD Capability)
Sensors / EW:
RSR-210N – (Surveillance, Helo) Radar
Role: Radar, Air & Surface Search, 2D Short-Range
Max Range: 55.6 km

Vigy Observer

Vigy Observer is a panoramic, stabilized shipborne observation system. Featuring a compact, modular design, it can be installed on any type of ship, from merchant marine freighters to coast guard interceptors or fast patrol boats, as well as warships.
Fitted with multiple optronic sensors and an excellent gyro-based stabilization system, Vigy Observer is easy to use day or night. Both small and light, it is easy to install, without requiring special tools or any changes to the boat’s structure. Vigy Observer comprises a control console, a joystick and a monitor, and is ready for immediate use after installation.


Aegis uses two slave illuminators to provide terminal flight guidance for the evolved Sea Sparrow missile. A Sagem Vigy 20 electro-optical and infrared tracker provides passive target tracking.

MK 81 AN/SPG-62 illumination radar x MK 81 AN/SPG-62  – NavantiaOficial

The AN/SPG-62 is a continuous wave, illumination radar for the Standard SM-2 missile in the Aegis air defense missile system. Three (DDG 51) or four (CG 47) Mk 99 missile control directors trigger the SPG-62′s illumination signal as the Standard missile nears its target, bathing the target in a coded signal that the missile’s semiactive homing seeker tracks until the missile explodes or hits the target.

  • BAND I/J
  • ANTENNA DIAMETER 7 ft 6 in (2.29 m)


Thales was awarded a contract in January 2009 to supply a new SATCOM system for the Nansen frigates, based on the Thales SURFSAT.


Nansen Class frigate weapons systems

The ship is armed with two modules each with four launch tubes for the NSM (naval strike missile) long-range anti-ship missile, developed by Kongsberg Defence & Aerospace for the Royal Norwegian Navy. NSM has inertial navigation mid-course guidance with GPS and an imaging infrared terminal seeker. It has a 125kg multi-purpose warhead and a range of 160km. NSM was cleared for series production in June 2007.

Eight-cell mk41 vertical launch system

The Norwegian Navy’s Fridtjof Nansen-class frigate had test fired the NSM during the RIMPAC exercise in July 2014. A Norwegian Navy photo Source

An eight-cell mk41 vertical launch system for the evolved Sea Sparrow missile (ESSM) has the capacity for 32 missiles, four per cell. ESSM has been developed by Raytheon with an international co-operative of ten NATO countries and is designed to counter high-speed anti-ship missiles. It has the same semi-active radar guidance and warhead as the Sea sparrow but has a new rocket motor and tail control to provide increased speed, range and manoeuvrability.


Mk 25 Quad Pack

The Mk 25 Quad Pack canister has been designed to be fit in a Mk 41 VLS cell. Each Mk 25 canister can accommodate up to 4 Evolved Sea Sparrow Missiles (ESSMs).

The Mk 25 canister will be adapted by many navies of the world which aim to replace their current Sea Sparrow missiles with state-of-the-art ESSMs. In addition, the Mk 25 provides additional time-critical benefits through replacing steered canisters by the vertical launch system. Source

Thor Heyerdahl (F 314) has 16-cell mk41 

Thor Heyerdahl (F 314) has 16-cell mk41

Sea Sparrow missile (ESSM) RIM-162 ESSM Sparrow missile (ESSM) RIM-162 ESSM

RIM-162 ESSM was developed by the U.S. Navy in cooperation with an international consortium of other NATO partners plus Australia. ESSM is a short-range, semi-active homing missile that makes flight corrections via radar and midcourse data uplinks. The missile provides reliable ship self-defense capability against agile, high-speed, low-altitude anti-ship cruise missiles (ASCMs), low velocity air threats (LVATs), such as helicopters, and high-speed, maneuverable surface threats. ESSM is integrated with a variety of U.S. and international launchers and combat systems across more than 10 different navies.

ESSM has an 8-inch diameter forebody that tapers to a 10-inch diameter rocket motor. The forebody includes a guidance section uses a radome-protected antenna for semi-active homing and attaches to an improved warhead section. A high-thrust, solid-propellant 10-inch diameter rocket motor provides high thrust for maneuverability with tail control via a Thrust Vector Controller (TVC).

ESSM’s effective tracking performance and agile kinematics result from S- and X-band midcourse uplinks, high average velocity and tail control, increased firepower through a vertical “quad pack” launcher (Mk-41 VLS), and greater lethality with a warhead designed for defeating hardened ASCMs.

Primary Function: Surface-To-Air and Surface-To-Surface radar-guided missile.
Contractor: Raytheon Missile Systems, Tuscson, Ariz.
Date Deployed: 2004
Unit Cost: $787000 – $972000 depending on configuration
Propulsion: NAMMO-Raufoss, Alliant (solid fuel rocket)
Length: 12 feet (3,64 meters)
Diameter: 8 inches (20,3 cm) – 10 inches (25,4 cm)
Weight: 622 pounds (280 kilograms)
Speed: Mach 4+
Range: more than 27 nmi (more than 50 km)
Guidance System: Raytheon semi-active on continuous wave or interrupted continuous wave illumination
Warhead: Annular blast fragmentation warhead, 90 pounds (40,5 kg)


Naval Strike Missile (NSM)

Naval Strike Missile (NSM) anti-ship and land-attack missile – Image

The Naval Strike Missile (NSM) is an anti-ship and land-attack missile developed by the Norwegian company Kongsberg Defence & Aerospace (KDA).

The original Norwegian name was Nytt sjømålsmissil (literally New sea target missile, indicating that it is the successor of the Penguin missile); the English marketing name Naval Strike Missile was adopted later.

NSM launch madule

HNoMS Fridtjof Nansen (F 310) shows NSM launch madule – Image

The Naval Strike Missile’s initial serial production contract was signed in June 2007. It has been chosen by the Royal Norwegian Navy for its new Fridtjof Nansen class frigates and Skjold class patrol boats.

 Solid fuel rocket booster, Microturbo TRI 40 turbojet
NSM 185 km (115 mi; 100 nmi)+
JSM 290 km (180 mi; 160 nmi)+
Sea skimming
High subsonic
Inertial, GPS, terrain-reference navigation, imaging infrared homing, target database

Kongsberg Defence Systems – Naval Strike Missile (NSM) Anti-Ship Live Firing 

The ship has two twin magazine torpedo launchers for BAE Systems Stingray lightweight torpedoes. One Oto Melara SuperRapid 76mm gun has a rate of fire of 120 rounds a minute.

Torpedo launchers

imageNansen Class torpedo launchers – Image

BAE Systems Stingray lightweight torpedoe

BAE Systems Stingray lightweight torpedoes

The original in-service version (Sting Ray Mod 0) entered service in 1983. It is propelled by a pump jet driven by an electric motor. Power is supplied by a magnesium/silver-chloride sea water battery. The propulsion method combines high speed, deep diving, agility and low noise levels. The weapon is provided with target and environmental information by the launching platform. Once launched it operates autonomously, with tactical software searching for the target using active sonar and then homing in without any further assistance. The software is designed to deal with the employment of countermeasures by the target. The weapon is designed to be launched from fixed wing or rotary winged aircraft and surface ships against submarine targets.

Sting Ray has a diameter of 324 mm (12 34 in) and a length of around 2.6 metres (8.5 feet). It has a launch weight of 267 kg (589 lb), and carries a 45 kg (99 lb) Torpex warhead. It has a speed of 45 knots (83 km/h) over a range of 8,000 metres (4.3 nautical miles). Source

Oto Melara SuperRapid 76mm gun

screenshotAtUploadCC_1503840787840One Oto Melara SuperRapid 76mm gun

Technical data:

Caliber: 3 inches / 76,2 mm
Barrel lenght: 186 inches / 4,72 meters (= 62 caliber)
Weight: 7900kg, empty (Super Rapid)
Shell: 76 x 900 mm / 12,34 kilograms
Elevation: – 15° to + 85°
Traverse: 360°
Rate of fire: Compact: 85 rpm / Super Rapid: selectable from single shot up to 120 rpm
Muzzle Velocity: 925 m/s (1100 m/s – DART)
Magazine: Compact: 80 rounds / SR: 85 rounds

16 kilometers with standard ammunition
20 km with extended range ammunition
up to 40 km with VULCANO ammunition

Le barillet de la tourelle de 76mm (© MER ET MARINE – VINCENT GROIZELEAU) – Image:

– HE (high explosive) – 6,296kg / Range 16km / effective range 8km (4km vs. air targets at elev. 85°)
– MOM (multi-role OTO munition)
– PFF (pre-formed fragmentation) – anti-missile ammunition
– SAPOM (semi-armored piercing OTO munition) – 6,35kg / Range 16km
– SAPOMER (semi-armored piercing OTO munition, extended range) – Range 20km
– DART (driven ammunition reduced time of flight) – sub-calibre guided ammunition against multiple targets
(missiles and maneuvering targets at sea) 4,2kg in barrel / 3,5kg in flight / 660mm lenght / effective range >8km
– VULCANO (76mm unguided and guided extended range ammunition) – under development

DART (driven ammunition reduced time of flight)


4 x 12.7 mm Browning M2HB HMG Sea Protector

ASW sensor suite

Thales Underwater Systems is prime contractor for the sonar suite with Simrad as a subcontractor. The suite includes the advanced CAPTAS mk2 V1 Combined Active / Passive Towed Array Sonar and the Spherion MRS 2000 hull-mounted sonar providing anti-submarine detection at short, medium and long ranges.

Spherion MRS 2000 hull-mounted sonar

Hull Mounted SonarHull-mounted sonar providing anti-submarine detection (Example)
General data:
Type: Hull Sonar, Active/Passive Altitude Max: 0 m
Range Max: 74.1 km Altitude Min: 0 m
Range Min: 0 km Generation: Late 2000s
Sensors / EW:
UMS 4131S [Spherion Mk3] – (Ex-TMS 4131S, MFS 2000 Processor) Hull Sonar, Active/Passive
Role: Hull Sonar, Active/Passive Search & Track
Max Range: 74.1 km



General data:
Type: VDS, Active/Passive Sonar Altitude Max: 0 m
Range Max: 129.6 km Altitude Min: 0 m
Range Min: 0 km Generation: Late 2000s
Sensors / EW:
UMS 4229 CAPTAS Mk2 – (Type 2087) VDS, Active/Passive Sonar
Role: VDS, Active/Passive Variable Depth Sonar
Max Range: 129.6 km


CAPTAS mk2 V1 includes a low-frequency active towed body, which uses free flooded ring (FFR) technology for transmission, providing a high source level in a compact array. The system has a triplet linear towed receiver array, which provides high definition left / right ambiguity resolution.

Sonobuoys can also be deployed.

Reutech Radar Systems RSR210N X-band 2D pulse Doppler radar is fitted for helicopter control and surveillance, under a contract awarded in December 2007. (see above)

Electronic warfare systems and countermeasures

The electronic warfare suite includes the ES-3701 tactical radar surveillance system (TRSS) from EDO Reconnaissance & Surveillance Systems (formerly Condor Systems Inc). ES-3701 combines precision electronic support measures (ESM) and radar warning receiver (RWR) functions.

ES-3701 Tactical Radar ESM and Surveillance System

This radar surveillance and precision mono-pulse DF system is an ideal ESM system for submarines, surface ships and land-based applications. The ES-3701 provides Situation Awareness, Targeting, Self-protection and Surveillance and utilizes a Windows HMI for graphical analysis and emitter display. The HMI can also be run on multifunction console.


ES 3701ES-3701 Tactical Radar ESM and Surveillance System – Image @Exelis inc

>>100% POI with interfering signal rejection
>>2-18 GHz standard instantaneous frequency coverage
>>360° instantaneous azimuth coverage
>>Provides precision long range over-the-horizon targeting
>>Processes modern complex radar signals
>>Multi-mode radar report merging
>>Multi-path and reflection processing
>>2-18 GHz receiver calibration and BITE
>>Built-in Training Simulator

>>1 million Pulse Per Second (PPS) signal environments
>>>10,000 emitter mode threat library capacity
>>Tracks 500 signals simultaneously
>>PDW preprocessing for high duty cycle
signal environments
>>Tunable 2-18 GHz CW notch filters for
OMNI and DF channels

>>-65 dBm automatic processing sensitivity
>>-70 dBm tangential signal sensitivity
>>60 dB instantaneous processing dynamic range
>>2° RMS DF accuracy over the entire dynamic range
>>3 MHz frequency measurement accuracy
>>50 nsec minimum pulsewidth measurement

>>Windows Workstation HMI
>>Real-time pulse analysis displays

Source Exelis inc

A Terma DL-12T decoy launcher dispenses infrared, radar and acoustic decoys. In March 2005, QinetiQ was awarded the contract to supply the LOKI acoustic torpedo countermeasures, to be deployed from the DL-12T launcher. Deliveries of LOKI to the Royal Norwegian Navy began in December 2007.

Terma DL-12T decoy launcher

Terma DL-12T decoy launcher – Image @terma.comTerma DL-12T decoy launcher dispenses infrared, radar and acoustic decoys

LOKI acoustic torpedo countermeasures

LOKI acoustic torpedo countermeasures

Integrated communications control system

The ship’s internal and external communications are managed by an integrated communications control system from Aeromarine. The communications suite includes tactical data link, link 11, prepared for link 16/22 and for SHF and UHF military satellite communications.

5556332_origRoald Amundsen (F 311) shows ship systems has been upgraded from earlier pictures

CODAG propulsion plant

The propulsion plant is in a CODAG combined diesel and gas turbine configuration, with two Izar Bravo 12V 4.5MW propulsion diesel engines and a GE LM 2500 19.2MW gas turbine.

CODAG combined diesel and gas turbine configuration

MTU CODAG Propulsion System. Combined diesel engine and gas turbine propulsion systems combine the benefits of both propulsion systems: for long-distance cruising or when traveling at low speed, the propulsion diesel engine only is used, whereas for high-speeds, the gas turbine can be added. Note the size of the gearboxes used to transfer the power from the different power sources to the shafts. Source: Rolls-Royce Power Systems AG press picture. (Example of CODAG propulsion system). Source

GE LM2500 21.5 MW gas turbine

·Combined diesel and gas (CODAG)

·Two BAZAN BRAVO 12V 4.5 MW diesel engines for cruising

·One GE LM2500 21.5 MW gas turbine for high speed running

·MAAG gearboxes

·two shafts driving controllable pitch propellers

·Bow Thruster Retractable (Electric) 1 MW Brunvoll

·Diesel generators 4 × MTU 396 Serie 12V 1250 KVA

The ship has a CODAG propulsion plant which gives a maximum transit speed of 27kt. Source BAZAN BRAVO 12V 4.5 MW diesel engines = NavantiaOficial

Electric bow thruster


A retractable 1MW electric bow thruster provides precise manoeuvrability when the ship is in confined areas. The bow thruster can be used as an auxiliary propulsion unit in an emergency if the main propulsion system is compromised.

The propulsion system gives a maximum speed of more than 26kt and a cruise speed of more than 18kt. The ship has two shafts with controllable pitch propellers, two rudders and a pair of active stabilising fins.

The ship’s diesel generators are four NTU 396 Series 12V 900kW.

Otto Sverdrup (F 312) – Image @vignette1.wikia.nocookie.netImage

Main material source

Updated Jan 08, 2018

6 thoughts on “Nansen Class Anti-Submarine Warfare Frigates, Norway

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