The Republic of Singapore Navy (RSN) submarine RSS Impeccable was received at Changi in Singapore on 20 July 2023, marking the arrival of the RSN’s first boat of the Kiel-built Invincible class, according to the Singaporean Ministry of Defence (MINDEF).
The boat had left Kiel on board the transport ship Rolldock Storm at the beginning of June. A photograph published by MINDEF shows RSS Impeccable entering RSS Singapura – Changi Naval base, where a homecoming ceremony was held.
As build number 2 of the four-boat programme, Impeccable is the first submarine of the class to arrive in Singapore. The first boat, Invincible, will remain in Germany to support crew training, but was christened in 2019 and delivered in the meantime. According to MINDEF statements from late February 2023, Invincible is “expected to return to Singapore later this year following completion of sea trials”.
Illustrious, boat number 3 in the programme, was named alongside sister ship Impeccable in Kiel on 13 December 2022 in the presence of German Chancellor Olaf Scholz. Shipyard thyssenkrupp Marine Systems (tkMS) was able to complete the factory sea trials of Illustrious this spring, but is not yet known when the boat will set sail for the Southeast Asian city state.
Impeccable will now carry out a series of sea trials to reach full operational capability.
The Type 218 SG/Invincible-class submarines are specially designed for deployment in the shallow and heavily trafficked tropical waters around Singapore. They will replace the RSN’s Archer- and Challenger-class submarines, which are now more than 60 and 40 years old respectively and were procured by Singapore to gain experience and expertise. After more than 20 years of service to the city-state’s navy, more modern submarines that can cope with the operational environment and security challenges of the next 30 years were overdue.
The Type 218 SG design has a low signature as well as some bespoke solutions. According to Singaporean officials, the state’s Defence Science and Technology Agency is said to have conducted modelling and simulation studies to optimise the design, equipment selection and layout of the boats, while also reducing their maintenance requirements.
With a length of 70 m, a pressure hull diameter of 6.3 m and a displacement of 2,000 tonnes on the surface (2,200 tonnes underwater), the Type 218 SG is a derivative of the Type 214. The boats combine an extended hull design and fuel cell air-independent propulsion (AIP) with features from the Type 212A. The class’ X-rudder stern configuration with propeller vortex diffuser is among the type’s special external features. The Type 218 SG’s underwater speed is said to be more than 15 kts, while above water the boat is said to be capable of more than 10 kts. The crew strength is 28.
The command and weapon deployment system of the Type 218 SG was jointly developed by Singapore Technologies Electronics and Atlas Elektronik. The current standard automation systems are supported by data analysis systems and decision support algorithms – so-called sense-making systems – to which the DSTA contributed to the development.
The Type 218 SG is equipped with the latest-generation Integrated Sensor Underwater System (ISUS 100) from Atlas Elektronik.
Experts assume that the Type 218 SG can be equipped with a selection of mission packages. The boat’s eight torpedo tubes will be armed with Leonardo’s Black Shark heavyweight torpedo as well as its advanced BSA variant in the future. There is also speculation regarding two additional torpedo tubes with a larger diameter (650 mm), which would allow the boat to be armed with cruise missiles.
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