Singapore signed a contract with TKMS for two new air-independent propulsion (AIP) submarines in December 2013. Initial details of the contract were scant, although a TKMS statement said the new design has been customised to meet the country's unique requirements, and includes capacity to accommodate additional equipment to meet future operational requirements. It will also feature an advanced combat system co-developed by Singapore Technologies (ST) Electronics, a subsidiary of Singapore defence prime ST Engineering Group, and the Bremen-based Atlas Elektronik.
Fresh details of the Type 218SG submarine finally emerged during the IMDEX 2015 exhibition that was held in Singapore in May 2015. According to specifications provided by TKMS, the Type 218SG will be 70 m in length, 6.3 m in beam, and will displace approximately 2,000 tonnes.
A company source told IHS Jane's that the Type 218SG is developed from the Type 214 design, although the new submarine has been extended in length to accommodate additional mission systems as well as to support future upgradability.
IHS Jane's was also told that the new design combines the "best features" of the Type 212A-class and the Type 214-class platforms. For example, the Type 218SG features an X-rudder stern configuration similar to the Type 212A, which offers enhanced manoeuvrability in confined littoral waters, as opposed to the Type 214's cruciform rudder arrangement.
"The Type 218SG will also use the same air independent propulsion (AIP) system found the Type 214 submarine," the source said. According to IHS Jane's Fighting Ships , the Type 214-class is equipped with an AIP system based on a pair of HDW/Siemens polymer electrolyte membrane (PEM) fuel cell modules that generate up to 120 kW each.
Unlike the RSN's current 1,500 tonne Archer-class SSKs (ex-Type A 17 Västergötland) that were modernised and refitted to accommodate a Stirling Mk 3 AIP system, the Type 218SG will be AIP-capable in its baseline configuration.
The new submarines will replace the RSN's ageing Challenger (Type A 12 Sjöormen)-class submarines, which were first commissioned in the 1960s for the Royal Swedish Navy and acquired by Singapore in the mid-1990s.
TKMS Type 218SG Submarine scale model.