Karel Doorman-class frigate

The Karel Doorman class is a class of eight multi-purpose frigates of the Royal Netherlands Navy. The class is also known as the "Multi-purpose" or M class.

The ships are named after famous Dutch naval officers, the lead ship being named after Karel Doorman.

Armament
These multi-purpose frigates can be used in the anti-submarine, anti-aircraft or surface combat roles. Their armament reflects that.

Their primary surface armament consists of two quad launchers for the RGM-84 Harpoon anti-ship missile, which has a range of 120 kilometres. Backing this up is a 76 mm Oto Melara gun, which has both anti-ship and anti-air capabilities.

Air defence is provided by the Sea Sparrow vertical launch system, which uses semi-active radar to find its target and has a range of 14 km. 16 VLS cells are mounted on the port external bulkhead of the hangar. A Goalkeeper system provides close-range air defence. It fires 30 mm rounds and can fire up to 4,000 rounds per minute, with a range of 200 metres to 3 km.

For anti submarine warfare, each ship is equipped with two twin torpedo launchers, firing Mark 46 torpedoes; and carries one Westland Lynx helicopter. The helicopter is also armed with 2 Mk 46 torpedoes, and carries dipping sonar and forward looking infrared (FLIR) systems.

Ships
All ships were built by Royal Schelde Dockyard

Sales to Chilean, Belgian and Portuguese Navies
In 2004 two ships, Tjerk Hiddes and Abraham van der Hulst were sold to Chile and renamed Almirante Riveros (FF-18) and Blanco Encalada (FF-15) respectively. Blanco Encalada commissioned into the Chilean Navy on 16. December 2005, with Almirante Riveros to be commissioned in April 2007.

On 20 July 2005, the Belgian government decided to buy two of the remaining six Dutch M-class frigates to replace the two remaining frigates of the Wielingen class (Wielingen and Westdiep) currently in service with the Belgian Naval Component, which in turn might be sold to Bulgaria. On 21. December 2005, Karel Doorman and Willem van der Zaan were sold to Belgium and renamed Leopold I (F930) and Louise-Marie (F931) respectively. They will be recommissioned between 2007- 2008.

In May 2006, Portugal's National Defense Minister, Luís Amado, showed interest in buying two Karel Doorman class frigates to replace the two remaining frigates of the João Belo class in service with the Portuguese Navy — instead of buying two frigates of the Oliver Hazard Perry class, offered by the United States. A committee of the Portuguese government arrived in the Netherlands to evaluate the condition of two frigates to be bought.

On November 1, 2006, the Portuguese Defense Minister Nuno Severiano Teixeira signed a contract for the purchase of the frigates Van Nes and Van Galen. Van Nes, renamed NRP Bartolomeu Dias (F333), was transferred to Portugal on January 16, 2009 and Van Galen, renamed NRP Francisco de Almeida (F334) was transferred on January 15, 2010. 

With the sale of two M-class frigates to Portugal only two of the eight ships remain with the Dutch Navy.

Modernisation Programme
The Royal Netherlands Navy and Belgium Navy decided to upgrade the four frigates by rebuilding both hangar and helicopter deck for the NH-90 as well to replace the forward mast for fitting the new Thales SeaWatcher 100 phased array surface search radar and Gatekeeper electro-optical surveillance system. The first ship to receive the upgrade was HNLMS Van Speijk F828 in April 2012, next will be BNS Leopold I F930, after her HNLMS Van Amstel F831 and BNS Louise Marie F931 will follow. SMART-S 3D search radars will not be replaced by SMART-S MK2.

Seawatcher 100 is a non-rotating active phased array radar for naval surface surveillance. The system automatically detects and tracks asymmetric threats and very small objects such as swimmers and periscopes in all weather conditions. Seastar can also be used for helicopter guidance.Seastar is internationally marketed as Sea Watcher 100

Gatekeeper is a 360° panoramic electro-optical surveillance and alerter system based on IR/TV technology. Designed to counter emerging asymmetric threats down to small boats and swimmers, Gatekeeper increases short-range situational awareness in littoral environments.