Taiwan's Indigenous Submarine 'Hai Kun' Set for April Sea Trials

Taiwan's first domestically built submarine, the Hai Kun, is on track to commence its Sea Acceptance Tests (SAT) in April 2025, as per the original schedule. This development comes despite earlier reports suggesting potential delays due to power supply issues encountered during Harbor Acceptance Tests (HAT).

Addressing Power Supply Concerns

In late February 2025, concerns arose regarding unstable voltage from ground facilities affecting the submarine's components during HAT. However, Taiwan's navy promptly refuted these claims, stating that the facilities are equipped with voltage stabilizers, ensuring stable power supply. Both the navy and the Ministry of National Defense confirmed that the SAT would proceed as planned in April.

Progress in Testing Phases

The Hai Kun has successfully completed critical pre-submergence and incline tests. Recently, it was moved to Dock No. 91 at the Port of Kaohsiung to facilitate tuning of its diesel-electric power plant and to conduct further harbor acceptance trials. This progression signifies readiness for the upcoming sea trials.

Specifications of the Hai Kun

The Hai Kun is a diesel-electric attack submarine, approximately 70 to 80 meters in length, with a displacement ranging between 2,500 and 3,000 tons. It features six torpedo tubes capable of launching Mk-48 Mod 6 torpedoes and UGM-84 Harpoon anti-ship missiles. The submarine is equipped with a combat management system developed by Lockheed Martin. The design incorporates a hybrid double-single hull structure with X-form rudders, similar to Japan's Soryu-class submarines. Notably, it does not feature air-independent propulsion (AIP) and is believed to lack anechoic coating.

Taiwan's Submarine Fleet Modernization

The Hai Kun is the first of eight planned submarines under Taiwan's Indigenous Defense Submarine (IDS) program, aiming to modernize the nation's aging submarine fleet. The program represents a significant step in enhancing Taiwan's naval defense capabilities amid regional security challenges.

The successful progression of the Hai Kun's testing phases underscores Taiwan's commitment to bolstering its maritime defense through indigenous technological advancements.