Invincible-class submarine

The Invincible-class submarines, formally classified as the Type 218SG submarines, are conventionally-powered diesel-electric attack submarines built for the Republic of Singapore Navy (RSN) by German-based naval conglomerate ThyssenKrupp Marine Systems (TKMS). Tailored to the operational requirements of the RSN, the model is derivative of the export-oriented Type 214 submarine, with specific design characteristics drawn from Type 212 submarines.

Source: Wikipedia — Invincible-class submarine (CC BY-SA 4.0)