Taiwan's New Submarine Hai Kun class Diesel-Electric (Patreon)

The Hai Kun-class submarine is a class of attack submarines built by CSBC Corporation, Taiwan for the Republic of China Navy. The program is also known as the Indigenous Defense Submarine (IDS) program. The submarines are diesel-electric and use lithium-ion battery technology for propulsion. They have a displacement of approximately 2,500 tons and a length of around 70 meters. The Hai Kun-class submarines are expected to be commissioned in 2025. The submarines are armed with MK 48 Mod6 AT torpedoes and UGM-84L Harpoon missiles.

The Hai Kun-class submarines are part of Taiwan’s effort to bolster its aging underwater fleets, which consisted of two Dutch-built Hai Lung-class submarines from the 1980s and two US-built GUPPY-class submarines that saw action in the Second World War. Taiwan has been attempting to procure new submarines since 2001, and in 2014, the Ministry of National Defense announced that Taiwan would construct its own diesel-electric attack submarines with help from the United States. In April 2018, President Donald Trump approved the technology transfers that would enable Taiwan to build its own submarines.

The Hai Kun-class submarine is thought to be reverse-engineered from the Dutch Zwaardvis class, which is currently operated by Taiwan, with some similarities to the Dutch Walrus class as well. The submarine features a hybrid double-single hull structure with a light outer hull, but replaces the cruciform control surfaces of the Zwaardvis class with the more prevalent X-form type rudders, resembling Japan’s Sōryū-class SSKs. It does not feature air independent power (AIP) and is believed to lack anechoic coating.