The Formidable class multi-mission frigates are manufactured by DCNS and ST Engineering. Credit: US Navy Mass Communication Specialist 2nd Class James R Evans.
The Formidable class vessel is fitted with Oto Melara 76mm gun with a firing rate up to 120 rounds per minute. Credit: melvil.
The first of the Formidable class, RSS Formidable, was commissioned in May 2007. Credit: melvil.
The maximum speed of the Formidable class vessel is 27k. Credit: Mass Communication Specialist 1st Class Kirk Worley.

Formidable class multi-mission frigates are versatile stealth warships capable of performing all dimensions of naval warfare, air, surface and underwater.

Six Formidable class multi-mission frigates were built for the Singapore Navy.

The Republic of Singapore Ministry of Defence (MINDEF) awarded the contract in March 2002 to DCN (now DCNS) in France for the design and construction of the frigates.

The contract included a technology transfer programme, under which the construction of the first frigate was carried out in France and then five additional frigates were built in Singapore by Singapore Technology Marine (STM) at the Benoi shipyard.

The frigate programme is named Project Delta and is being managed by Singapore’s state-owned Defence Science and Technology Agency (DSTA).

The first of class, RSS Formidable, was launched in January 2004 at the Lorient dockyard in Brittany, France. The frigate arrived at Changi Naval Base, Singapore, in August 2005 and was commissioned in May 2007. The six Formidable Class frigates were declared fully operational in January 2009.

Formidable class frigates

The class consists of RSS Formidable (68), RSS Intrepid (69) launched in July 2004, RSS Steadfast (70) launched in January 2005, and RSS Tenacious (71) launched in July 2005 – all commissioned in February 2008; RSS Stalwart (72) launched in December 2005 and delivered in October 2007; and RSS Supreme (73) launched in May 2006 and delivered in August 2008. Stalwart and Supreme were commissioned in January 2009.

The frigates replaced the six Sea Wolf Class missile gunboats that entered service in 1972 and are approaching the end of operational life.

Formidable class frigates design

The Project Delta design is a smaller derivative of the French La Fayette Class stealth frigate with low radar, acoustic, infrared, and electromagnetic signatures.

A high level of automation and closely integrated combat and ship management systems have been selected to enable the frigate to be operated with a crew of just 70. The overall length is 114.8m with a beam of 16.3m and a draught of 6m. The full load displacement is 3,200t.

Command and control

The combat management system was developed by the state-owned DSTA with ST Electronics to meet the operational requirements of the Republic of Singapore Navy. DSTA also has responsibility for combat systems integration. The standard operating common consoles, with 20in LCD displays, are supplied by Singapore Technologies Electronics, a subsidiary of ST Engineering.

The Integrated Communications System is also supplied by Singapore Technologies Electronics.

Formidable armament

The frigate is armed with the Boeing Harpoon surface-to-surface anti-ship missile. The Harpoon missile has a range of 130km and uses active radar guidance. The missile is armed with a 227kg warhead.

“Six Formidable cClass multi-mission frigates were built for the Singapore Navy.”

The frigate is fitted with the DCNS Sylver vertical launch system with MBDA Aster 15 surface-to-air missiles. There are four eight-cell SYLVER A43 launch modules with 32 missiles.

The two-stage Aster missile is a high-agility and high-manoeuvrability defence missile for deployment against incoming sea-skimming anti-ship missiles, which use evasive terminal manoeuvres and re-attack modes. In anti-missile mode, the Aster 15 has a range of 15km. Aster also provides protection against manned and unmanned aircraft to a range of 30km.

The main gun is the Oto Melara 76mm / 62 Super Rapid gun, which fires 6kg shells to a range of 16km at a firing rate of up to 120 rounds a minute.

Anti-submarine warfare

The EDO Model 980 ALOFTS active low-frequency towed sonar provides long-range detection and classification capability against submarines. ALOFTS comprises a variable depth sonar (VDS) towed body with a towed array. The frigate has two triple-barrelled lightweight torpedo launchers and is armed with the Eurotorp A244S torpedo.

Frigate aircraft capacities

The frigate has the capacity to operate a single medium-size helicopter in the 10t class. The helicopter deck at the stern, approximately 22m×16m (360m²), has a single landing spot. The hangar is fully equipped with helicopter support and maintenance systems. The frigate carries 15 additional aircrew for helicopter flight operations.

The Republic of Singapore Air Force will fly the shipborne helicopter and the helicopter mission crew will be from the Republic of Singapore Navy. In January 2005, MINDEF placed an order for six Sikorsky S-70B Seahawk helicopters to operate from the frigates.


The Herakles multi-function radar, supplied by Thales, is the frigate’s primary surveillance radar. The phased array radar is a passive, three-dimensional, search and fire control radar operating over E and F bands.

The radar, installed in a radome on top of the main mast, carries out long-range air and surface surveillance and weapon control. The Herakles radar is integrated with the Aster air defence missile system.

The frigates surface search and navigation radar is the Terma Scanter 2001, operating at I-band.


The vessel’s electronic support measures (ESM) system is the Rafael C-PEARL-M radar intercept. C-PEARL-M is a lightweight ESM system consisting of two line replaceable units (LRU) – an antenna unit and a receiver-processor unit – which provide automatic detection, data measurement, and identification of threats.

Three Sagem Défense Sécurité (formerly EADS Defence & Electronics) new-generation Dagaie systems (NGDS) are fitted. Each system consists of a pair of two-axis launchers with 12 infrared, radar, or acoustic decoys.


The frigate is powered by four MTU 20V 8000 diesel engines in a combined diesel and diesel (CODAD) configuration. Each engine is rated at 8,200kW. The engines drive two shafts with constant pitch propellers.

The cruise and maximum speeds are 18k and 27k and the range is 7,200km (4,000nm).