COLUMN | Taiwan’s first indigenously-built submarine: roles and capabilities [Naval Gazing]

Driven both by concerns over Chinese maritime expansionism and desires to enhance national prestige, many Asian countries are acquiring diesel-electric powered attack submarines.

Recent years have seen Vietnam, Indonesia, Myanmar, Bangladesh, Thailand, and the Philippines joining established submarine regional operators such as Japan and South Korea in either commissioning modern boats or enacting plans to do so.

Meanwhile, in late September, Taiwan launched the future Hai Kun, the first of a planned class of eight indigenously-designed boats to be built in Kaohsiung by Taiwan’s CSBC Corporation following sea trials and training. It is due to join the two upgraded Netherlands-built Hai Lung-class subs in Republic of China Navy (RoCN) service in 2025..

A discreetly multi-national project

Hai Kun measures 66.9 metres long, displaces 2,500 tonnes, and has a maximum submerged speed of 20 knots. Analysts assess that its design blends some features of the Soryu-class submarines of the Japan Maritime Self-Defence Force (JMSDF) with those of the Hai Lung-class boats with an emphasis on enabling quiet underwater running. The boat was reportedly built using Japanese construction techniques.

Lithium-ion batteries will provide high endurance, although, as with other diesel-electric powered boats, it will be vulnerable while snorting at periscope depth in order to operate its diesel generators to recharge the boat’s batteries. The snorting operation radically increases the submarine’s radar, acoustic, infra-red, and visual signatures for the duration of the snort.

The submarine’s armament includes heavyweight Mark 48 torpedoes as well as underwater-launched Harpoon anti-shipping cruise missiles. It will be fitted with advanced US-supplied surface and underwater sensors and control systems including a Lockheed Martin combat management system and a bow-mounted Raytheon active sonar.

Nowadays, few nations are cowed by Beijing’s threats of retribution should any country provide military assistance to Taiwan. Countries that have reputedly contributed expertise towards Taiwan’s submarine project include Canada, the UK, Australia, South Korea, India, and Spain. It remains to be seen whether this assistance will be extended to the vital area of RoCN submarine crew training.

Implementation of the project has been administered through Gibraltar-based consultancy Gavron, led by former UK Royal Navy Commodore Ian McGhee.

Deterrent, intelligence gathering and surveillance roles

The prime role of Hai Kun and its sister boats will be to deter and, if necessary, respond to an attack on Taiwan by the People’s Republic of China (PRC). Analysts believe that the threat of a very risky seaborne invasion of Taiwan’s main island of Formosa is fading, but that blockade and bombardment of Formosa remain realistic possibilities. Also feasible are attacks on Taiwan’s offshore islands, particularly as only one of these outposts, Penghu, (Pescadores Islands) is covered by the US Congress’ Taiwan Relations Act. The legislation enables a US response to an attack by the PRC.

The submarines’ quietness, agility, modern weaponry and sensors, and low sonar cross-section mean that they will pose a major potential threat to hostile surface ships. They are also likely to prove difficult opponents for the Yuan-class diesel-electric and Shang-class nuclear-powered boats of the People’s Liberation Army Navy (PLA-N).

Electronic intelligence collection and sustained covert surveillance of strategically significant sea and shore areas are likely additional operational requirements. The RoCN intends to operate the new subs in conjunction with indigenous Seawolf autonomous underwater vehicles.

A boost for Taiwanese morale

Widespread domestic coverage of the launch of Hai Kun was likely intended to boost the morale of the offshore democracy’s population at a time of increasingly proactive operations by Beijing’s sea and air forces. PRC warplane and warship activity around Taiwan is now a daily occurrence, while in the South China Sea, China Coast Guard patrol ships are now routinely harassing Filipino civilian and naval supply vessels in the vicinity of the Manila-claimed territories of Second Thomas Shoal and Thitu/Pag-Asa Island.