Formidable-class frigate
The "Formidable"-class multi-role stealth frigates are the latest surface platforms to enter into service with the Republic of Singapore Navy, and are multi-mission derivatives of the French Navy's . The six ships form the First Flotilla of the RSN. Planning and acquisition. The search for a replacement for the aging "Sea Wolf"-class missile gunboats, which entered into service in 1972, started in the mid-1990s. The United States, Sweden and France participated in the bid for the contract. In March 2000, the Singapore Ministry of Defence awarded the contract to DCNS for the design and construction  of six frigates. A key feature of the contract was the technology transfer arrangement. Under the arrangement, DCNS was to design and build the first frigate in its Lorient yard in France while the remaining five frigates were to be built locally by Singapore Technologies (ST) Marine at its Benoi yard in Singapore. Subsequent maintenance and mid-life retrofit will be done by ST Marine. Construction of "Formidable" began in late 2002, when the keel was laid down in Lorient in November 2002. Design and construction. Radar cross section (RCS) reduction features have been incorporated into the "Formidable" class design , with inclined hull sides and bulwarks as well as concealment of ship boats and replenishment-at-sea equipment behind low-RCS curtains. The "Formidable" class have a significantly reduced profile than the "La Fayette" class and its other derivatives, due to the smaller superstructure and the use of enclosed sensor mast technology. The frigate is also constructed entirely of steel, unlike the "La Fayette" class which makes extensive use of weight-saving composite structures in its aft superstructure block. The frigates also possess better sea keeping qualities and are able to stay at sea for longer periods of time. Sensors  and systems. The frigates are equipped with the Thales Herakles passive electronically scanned array multi-function radar, which provides three-dimensional surveillance for up to . The radar provides all-round automatic search and tracking of both air and surface targets, and is integrated with the MBDA Aster air defence system. Utilising the DCNS Sylver vertical launch system (VLS), each frigate is equipped with 32 cells. It is reported that the frigates have a special surface-to-air missile configuration, combining the Thales Herakles radar with the Sylver A50 launcher and a mix of Aster 15 and 30 missiles. The "Formidable"-class  frigates are key nodes within the Singapore Armed Forces' Integrated Knowledge-based Command and Control network, a concept similar to the United States Department of Defense's network-centric warfare doctrine. The locally developed Combat Management System integrates all the sensors and weapon systems on board, and a dual Fast Ethernet data transfer system forms the backbone of this system. Each frigate has a span of influence that stretches up to about , where it acts as the Navy's mobile operations centre out at sea and receives information from sister ships and aerial assets deployed within the range. The Combat  Management System will then make sense of the different data, establish an accurate picture of the area of operations, and send the information back to shore and to its army and air force counterparts. This increases battlespace awareness and allows little time for the enemy to react due to the short sensor-to-shooter loops. Armament. The frigates are equipped with Boeing Harpoon missiles and Oto Melara 76 mm guns for surface defence. The Harpoon missile has a range of and uses active radar guidance. It is armed with a warhead. There is space for as many as 24 Harpoon  missiles at the center of ship making it the most well armed ship of its class. The gun fires shells to a maximum range of at a firing rate of up to 120 rounds per minute. The frigates are also equipped with the EDO Corporation active low frequency towed sonar to enable long range submarine detection and classification, as well as EuroTorp A244/S Mod 3 lightweight torpedoes fired from two B515 triple-tube launchers hidden behind the bulwark. The frigates are equipped with Sikorsky S-70B naval helicopters, an international derivative of the United States Navy Sikorsky SH-60B Seahawk. The  Ministry of Defence signed a contract with Sikorsky Aircraft Corporation in January 2005 to acquire six of these helicopters, which will be organic to the frigates. Each of these naval helicopters are equipped with a Telephonics AN/APS-143 "Ocean Eye" X-band maritime surveillance and tracking radar, a L-3 Communications Helicopter Long Range Active Sonar (HELRAS) dipping sonar, EuroTorp A244/S Mod 3 torpedoes and a Raytheon AAS-44 electro-optic system to provide infrared detection and tracking. The naval helicopters will be raised as a squadron in the Republic of Singapore Air Force and piloted by air force pilots, but  the system operators will be from the Navy. Operational history. The six frigates form the 185 Squadron of the RSN. RSS "Formidable" participated in Exercise Malabar 07-2 in September 2007, a Theater Security Cooperation engagement involving the navies of the United States, India, Australia, Japan and Singapore. The exercise involved more than 20,000 personnel on 28 ships and 150 aircraft, including the USS "Kitty Hawk" Carrier Strike Group. RSS "Intrepid" conducted the navy's inaugural live firing of the French-made Aster 15 surface-to-air missile on 2 April 2008, off the French coast of Toulon. The frigate  successfully shot down an aerial drone simulating an enemy target with an Aster missile. It was reported that the frigate sailed halfway round the world to test fire the Aster missiles due to the crowded air and sealanes around Singapore and the lack of an instrumented firing range needed by defence engineers to track and measure the performance of the Aster missile. RSS "Steadfast" participated in the world's largest multilateral naval exercise RIMPAC for the first time from 27 June to 31 July 2008, which involved 20,000 personnel from 10 countries operating over 35 ships, six submarines and over  150 aircraft. During this exercise, RSS "Steadfast" launched a Harpoon missile on a decommissioned USN warship on 14 July 2008 and also refueled at sea with a contingent of USN vessels. Participation in this exercise also validated the RSN's ability to conduct sustained sea operations. On 16 November 2009, the Republic of Singapore Air Force established its Peace Triton Sikorsky S-70B Seahawk Naval Helicopter detachment at the USN Maritime Strike Weapons School in San Diego, California to undertake qualification and operational training under the umbrella of the USN's SH-60F Aircraft Qualification Course. RSS "Stalwart" was deployed to southern  California to support ship/air integration activities. On 25 March 2010, the Minister for Defence Teo Chee Hean announced that the Seahawk integration programme had successfully concluded with a "high-tempo, week-long exercise" involving assets from both the RSN and USN, including five surface ships, a submarine, maritime patrol aircraft and F/A-18 Hornet combat jets. In September 2012 the RSN deployed RSS "Intrepid" and an S-70B naval helicopter in support of Combined Task Force 151 (CTF 151), a multinational effort to fight piracy in the shipping lanes off Somalia. This was the first operational deployment of a Formidable -class frigate and naval helicopter for counter-piracy operations in the Gulf of Aden. This was followed by a second deployment in March 2014 of a task group comprising RSS "Tenacious" and another S-70B, the fifth such mission undertaken by the SAF. On 9 March 2014, RSS "Steadfast" was deployed along with other air and sea assets to assist with the search and rescue operations of Malaysia Airlines Flight 370. In December 2014, RSS "Supreme" was deployed in the search for Airasia Flight QZ8501 after it crashed into the Java Sea on 28 December 2014; along with RSS "Valour", RSS  Persistence, RSS "Kallang", MV "Swift Rescue", and two Lockheed C-130H Hercules. On 26 July 2021, RSS "Intrepid" conducted a passage exercise with HMS "Queen Elizabeth", the flagship of United Kingdom Carrier Strike Group 21 and her escort ships, together with RSS "Unity" and RSS "Resolution", marking the first time the RSN has conducted an exercise with a UK Carrier Strike Group. On 2 March 2022, MINDEF announced plans to upgrade the Formidable class frigate as part of its plans for a modernized, next generation SAF 2040. This entails comprehensive upgrades to all of its subsystems, including armament, combat systems and  communications equipment.