Taiwan's Hai Kun (SS-711) SSK Explained

The Republic of China (Taiwan) attained a significant national security milestone o September 28 when its first of eight domestically built diesel-electric submarines, the Hai Kun (SS-711), was rolled out at the Chia Shipbuilding Corp’s (CSBC) shipyard in the southern port-city of Kaohsiung. Costing US$1.54 billion, the SSK was built under the Indigenous Defence Submarine (IDS) programme, codenamed Project 1168. Taiwan launched its IDS programme in 2014. Following which the RoC Navy (RoCN) and CSBC signed a construction contract in May 2016. Keel-laying took place on November 24, 2020. Admiral Huang Shu-kuang, Taiwan’s Chief of the General Staff and convener of the IDS programme, revealed that the harbour acceptance tests of this SSK will start on October 1 and should end on April 1, 2024. The next stage will be sea-acceptance trials, but said there is no fixed timeline for this phase as it is Taiwan's first locally-produced SSK. Present plans call for the SSK to be delivered to the RoCN in 2025.

Hai Kun SS-711 has a domestic material content of 40%. 25 technologies involved in manufacturing the SSK are divided into three categories: red zone, yellow zone, and green zone. Taiwan has only mastered 10 of them (the green area is equipment that can be produced by itself), 9 items have difficulties (yellow area, the technology is difficult to obtain, but there are parts with self-made potential), and the remaining 6 items are core technologies In the red zone, there is no self-research ability, and it was necessary to seek external assistance technology). The hull-design comes from The Netherlands’ DAMEN Shipyards.

The SSK is about 70 metres long, 8 metres wide, and has an underwater displacement of 2,500 tons. It uses a single-hull design that features an X-shaped tail rudder. The hull is made of HSLA-80 CRHS56 steel supplied by ArcelorMittal. The SSK is powered by MTU Series 12V 4000 diesel engines that drives a 7-blade propeller. MTU also supplied the electric generators. The lead-acid batteries were supplied by a Taiwanese company. The submarine can dive to a depth of 420 metres. The SSK has six Germany-supplied 533mm torpedo tubes that can launch Honeywell Mk.48 Mod 6AT heavyweight torpedoes, as well as UGM-84L Harpoon anti-ship cruise missiles.

All the US-sourced hardware was ordered through TECRO, the “Taipei Economic and Cultural Representative Office in the United States”. Lockheed Martin Naval Electronics & Surveillance Systems–Undersea Systems is the prime systems integrator, while Northrop Grumman has supplied the bow-mounted active and passive cylindrical sonar array, wide-aperture passive arrays on the flanks, and high-frequency active arrays on the keel and fins. Raytheon has supplied a derivative of the CCS Mk.2 combat management system and a derivative of the AN/BYG-1 combat control system. L-3 MAPPS has supplied the integrated platform management system (IPMS), communications system and battle damage control system, while L-3 KEO has supplied all the masts and periscopes. A Sperry Marine AN/BPS-16(V)4 navigation radar, operating at I-band, is fitted as well. Taiwan’s National Chung-Shan Institute of Science & Technology developed a Torpedo Countermeasure System and integrating it into the SSK with two 6-shot cannisters mounted on each side of the submarine, enabling the SSK to counter active and passive homing torpedoes with soft kill capability.