Taiwan’s first locally built submarine faced new doubts over whether the vessel could meet a November delivery deadline to the island’s navy as it had yet to begin long-awaited sea trials, with a new schedule yet to be confirmed.
The Hai Kun, or Narwhal, part of Taiwan’s Indigenous Defence Submarine (IDS) programme, had originally been slated to begin Sea Acceptance Tests (SAT) in April. But there had been no sign of progress by the end of the month, despite earlier pledges from the military that testing would proceed on schedule.
Former navy captain Kuo Hsi, who served as a construction adviser on the project, said during a recent live-streaming on social media that repeated piping system failures had resulted in compartment flooding, forcing foreign testing teams to suspend work.
Do you have questions about the biggest topics and trends from around the world? Get the answers with SCMP Knowledge, our new platform of curated content with explainers, FAQs, analyses and infographics brought to you by our award-winning team.
“Pipes have broken or been pulled loose again,” Kuo said recently on a social media political talk show. “Do you know how many times water has rushed into the Hai Kun?”
He added that the vessel had not yet completed its Harbour Acceptance Test, a prerequisite for proceeding to sea. “There are more than 4,000 checkpoints for the Integrated Platform Management System [IPMS], but fewer than 400 have been tested,” Kuo said on the programme.
“So far, not even 10 per cent. And you think it can go to sea in April? How?”
Given the delays in IPMS testing, Kuo doubted the SAT could begin in June, much less be completed by the end of September, as previously planned.
The navy declined to comment on Kuo’s statements, but did confirm in a statement on Monday that the Hai Kun’s major systems were still undergoing joint testing and calibration. “The shipbuilder, original system technicians and oversight teams are collaborating in accordance with contract and acceptance standards,” it said in the statement.
On Tuesday, Vice-Admiral Chiu Chun-jung, chief of staff of the Taiwanese navy, said the Hai Kun had entered the final phase of preparations before sea trials. “Once safety checks and testing procedures confirm that conditions are met, a date for deployment at sea will be set,” he said at a news conference, adding that the navy was managing the process to ensure the vessel was delivered on schedule by November.
A military source familiar with the matter, speaking on condition of anonymity, said the most critical phase of sea trials would involve the test-firing of an exercise torpedo. “That firing was initially scheduled for late October,” the source said. “If all tests pass, final delivery to the navy would follow in November. But with sea trials still hanging in the air, it’s difficult to say if that timeline can be met.”
Taiwanese Defence Minister Wellington Koo acknowledged last month that a schedule for the sea trial “cannot yet be confirmed, but we hope to proceed as soon as possible”. “CSBC Taiwan [the shipbuilder] is working overtime to address the issues,” Koo told reporters on April 23.
“We’ve instructed the navy to ensure safety standards are fully met before going to sea.”
Defence analysts said setbacks like water leaks were “not uncommon” considering that it was the first submarine produced by Taiwan.
“Submarine piping systems must withstand pressure when submerged,” said Shu Hsiao-huang, a senior analyst at the military-affiliated Institute for National Defence and Security Research (INDSR). “If pressure conditions during harbour testing aren’t simulated correctly, pipe ruptures and water ingress can occur.”
“Flooding issues aren’t unusual during shipbuilding. That is exactly why harbour tests are so important,” said Hsinbiao Jiang, also of INDSR, adding that foreign contractors would not go to sea unless those tests were completed. “Why would they risk their lives otherwise?”
The Hai Kun prototype, which cost NT$26 billion (US$898 million), is equipped with diesel-electric propulsion and an X-shaped rudder for manoeuvring in shallow waters. It carries a US-made Lockheed Martin combat system and will be equipped with MK-48 heavyweight torpedoes.
In August 2024, Taiwan approved a NT$284 billion plan to construct seven additional submarines over the next 14 years – an ambitious expansion aimed at boosting the island’s undersea deterrence in the face of growing cross-strait tensions.
Beijing, which sees Taiwan as part of China to be reunited by force if necessary, has ramped up military pressure on Taiwan since Tsai Ing-wen was elected the island’s leader in 2016 and refused to accept the one-China principle.
Most countries, including the US, do not recognise Taiwan as an independent state, but Washington is opposed to any attempt to take the self-governed island by force and is committed to arm Taiwan.
More from South China Morning Post:
- First Taiwan-made submarine Hai Kun on track for April sea trials, defence ministry says
- First made-in-Taiwan submarine unveiled as island seeks to strengthen naval defences
- Mainland China piles on the pressure to Taiwan’s east in a twist on old tactics
- China’s military reveals details of Type 094 nuclear submarine for first time
For the latest news from the South China Morning Post download our mobile app. Copyright 2025.
