- Taiwan unveiled its first domestically made submarine in late September.
- The vessel can carry heavyweight Mk-48 torpedoes that can rip through ships and subs.
Taiwan has unveiled its first domestically built submarine, a major step forward in bulking up the island's naval combat capabilities.
The vessel's ability to carry a powerful heavyweight torpedo capable of defeating ships and submarines — the US-made Mark 48, or Mk-48 — is a real eye-catching feature. Armed with this weapon, Taiwan's submarine represents a new challenge for China.
"The inclusion of the Mk-48 is a significant upgrade" for Taiwan, Tom Shugart, a former US Navy submarine commander who's now an adjunct senior fellow at the Center for a New American Security think tank, told Insider. "They can strike with very little warning, and they're deliberately designed to break ships in half."
On September 28, Taiwan launched its first locally made, diesel-electric submarine at a shipyard in the southwest city of Kaohsiung. The vessel — its English name "Narwhal" and Mandarin name "Hai Kun" — is the first sub of the island's Indigenous Defense Submarine program, a top priority in Taipei. Taiwanese President Tsai Ing-wen's plan predicts the new sub will be joined by two others by 2025, with an additional five others coming later.
While Taiwan already has two Dutch-made submarines from the 1980s and two even older former US Navy subs commissioned in the 1940s and later transferred to Taiwan in the early 1970s, the "Narwhal" is a marked improvement over the others, an upgrade to the country's undersea naval warfare capacity, and a demonstration that the island maintains a robust defense industry.
"Taiwan had to essentially do this using indigenous technology," Bryan Clark, a former US Navy officer who's a defense expert at the Hudson Institute, told Insider, adding that the six-year timeline for building the "Narwhal" was "as fast as other countries have been doing for decades."
Taiwan received some foreign support, but its geopolitical isolation, as well as China's efforts to strangle international engagement with the island, impacted these efforts, as they have previous attempts to acquire more modern submarine technology.
"One problem that Taiwan has had, particularly with its submarines, is that countries are unwilling to share technology or sell them" the vessels, Clark said.
US support for the new submarine dates back to at least April 2018, when President Donald Trump approved sending weapons technology to Taiwan. At that time, Taiwan purchased 46 Mk-48 Mod 6 Advanced Technology Heavy Weight Torpedoes, envisioned as a major weapons-capability upgrade for the fleet that would be delivered by 2028. Sources suggested earlier this year that they'll be fast-tracked and delivered by 2025.
Originally designed in the late 1960s and deployed in the late 1980s, the Mk-48 torpedo was intended to counter advances in Soviet submarine technology. It's been extensively upgraded since then, but the core purpose — to locate, acquire, and attack targets — remains the same. Launched from a sub's torpedo tubes, the Mark 48 can be guided by a wired combat system or pre-programmed to find its target.
To strike ships in naval combat, operators would specifically employ the torpedo to hit a ship's underside or keel, the long supportive structure running from stem to stern. The Mk-48's ability to pulverize the keel, effectively breaking the backbone of a ship, is what makes it so deadly. This rips the ship in two, and if the torpedo misses on its first launch, it can swing back around and try again.
"The Mk-48 is probably the most capable torpedo in the world. It's dual purpose and can be used in anti-submarine warfare or against surface ships," Shugart said, adding that the "extremely hard-hitting, very long range, and very fast" torpedo gave Taiwan "the ability to threaten China's most powerful warships in a very direct way."
Speaking on the capabilities of Taiwan's new submarines, Adm. Huang Shu-kuang, the head of the Indigenous Defense Submarine program, said recently, "If we can build up this combat capacity, I don't think we will lose a war."
Although they represent a new threat, one that could deal serious damage, better torpedoes on a new submarine or even a fleet of those submarines probably wouldn't be enough to stop a full-scale People's Liberation Army invasion, defense experts say.
While the new vessels can carry punishing Mk-48s, a hypothetical Chinese military invasion of Taiwan would be "on such a scale" that these submarines "would contribute, but they're not going to be the thing that makes the difference," said Clark.
Rather than combatting an invasion, the "Narwhal" sub and Taiwan's planned acquisition of more subs and Mk-48s could serve a different purpose.
A fleet of armed submarines could deter some smaller military actions or blockades that might be considered grey areas for US or allied intervention, limiting China's options to isolate Taiwan without a full-fledged invasion — military action that comes at tremendous risk for Beijing. The new submarine and the deadly torpedoes able to pummel enemy warships if shots are fired "puts China on notice that they've lost a tool in the kit for keeping Taiwan," Clark said.
China has never taken the use of force off the table in its dealings with the independent island nation, which Beijing argues is an inseparable part of China's sovereign territory.
US military officials have previously expressed concerns over the possibility of an attack, such as Adm. Philip Davidson, who warned when he was head of US Indo-Pacific Command that the world could see China act as early as 2027. Fears of Chinese military intervention in the area have only spiked since Russia's full-scale invasion of Ukraine in February 2022.
While the Mk-48 is a powerful weapon, it's not the only valuable asset the "Narwhal" could carry. It would only take a few modifications to the sub's US-made fire-control system for it to carry Harpoon antiship missiles and to the torpedo tube to launch Maritime Strike Tomahawks. Huang said later models would leave the door open for antiship missiles.
Taiwan already has ship-launched versions of the Harpoon, and plans were in place earlier this year to buy 400 land-launched versions from the US, although the shipment most likely won't get there until after 2027. Taiwan is far less likely to get Tomahawk missiles any time soon or at all.
But even if Taiwan's sub were able to carry these, the Mk-48 still boasts certain advantages.
"Unlike a Harpoon or a Tomahawk, you can't shoot down a torpedo that's on its way to its target. That's even if you detect it, even if you see it coming," Shugart said.
And, assuming Taiwan could even get it, the Maritime Strike Tomahawk has a range that Taiwan probably wouldn't be able to take full advantage of in a defense scenario. Also, "it's not particularly fast, it's not particularly stealthy," Shugart told Insider, explaining "that's going to be a missile that Chinese air-defense ships will be able to see coming and will have relatively more time to shoot down before [the missile] gets to something." These considerations make the Mk-48 torpedo key.