Impeccable, a submarine built in Germany for the Republic of Singapore Navy (RSN) and launched in December last year, was loaded on 18 May 2023 in preparation for the transfer to its home nation. The transport ship Rolldock Storm has left Kiel on 1 June with the boat as cargo.

Impeccable was launched on 13 December 2022 in the presence of German Chancellor Olaf Scholz together with its sister ship, Illustrious. The shipyard thyssenkrupp Marine Systems (tkMS) was able to complete the factory sea trials this spring. It is not yet known when Illustrious will set sail for the Southeast Asian city state.

Impeccable and Illustrious are among four Type 218SG submarines that Singapore ordered in 2013. The first boat, Invincible, was christened in 2019 and delivered in the meantime. According to statements made by the Singaporean Ministry of Defence (MINDEF) at the end of February 2023, it is “expected to return to Singapore this year after completion of sea trials”.

Construction of the fourth submarine, Inimitable, is ongoing. The cost of the programme was put at USD 2.4 Bn (EUR 2.23 Bn) in a parliamentary question, with the Singaporean defence minister referring to comparable boats of South Korea and Turkey in his reply of 9 January 2023.

The Invincible-class submarines are specially designed to operate in the shallow and heavily trafficked tropical waters of Singapore. They are to replace the RSN’s Archer- and Challenger-class submarines, which are now more than 60 and 40 years old respectively. These boats were procured by the RSN to gain experience and expertise, but, after more than 20 years of service, more modern submarines that can cope with the operational environment and security challenges of the next 30 years were overdue.

The Type 218SG design features a low signature and has some bespoke solutions. According to Singaporean officials, the Defence Science and Technology Agency of the Republic of Singapore (DSTA) is said to have conducted modelling and simulation studies to optimise the design, equipment selection and layout of the boat, as well as reducing the type’s 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 and 2,200 tonnes submerged, the Type 218SG is a derivative of the Type 214 design. The boats combine an extended hull design and fuel cell air-independent propulsion (AIP) with features from the Type 212A. The boat’s X-rudder stern configuration with propeller vortex diffuser is among the special external features. The type’s underwater speed is said to be more than 15 kts, while above water the boat can travel at more than 10 kts. The crew strength is 28.

The command and weapon deployment system of the Type 218SG was jointly developed by Singapore Technologies Electronics and Atlas Elektronik. The current standard automation systems are supported by data analysis systems and algorithms for decision support – so-called sense-making systems to which DSTA contributed to the development.

The Type 218SG is to be equipped with Atlas Elektronik’s latest-generation Integrated Sensor Underwater System (ISUS 100).

It is expected that Type 218SG can be equipped with a choice of mission packages. The type’s eight torpedo tubes will launch Leonardo’s 533 mm Black Shark heavy torpedo and, in future, its more advanced BSA version. There is also speculation about two additional torpedo tubes with a larger diameter (650 mm), which would facilitate the launching of cruise missiles.

Defence co-operation between Germany and Singapore was strengthened in 2018 with the signing of a bilateral accord, while high-level visits and dialogues take place frequently. Most recently, Germany’s Inspector of the Navy, Vice Admiral Jan C Kaack, was received by Singaporean Minister of Defence Dr Ng Eng Hen on 3 May 2023.

Hans Uwe Mergener