What Good Is An Attack Submarine With No Torpedoes? Taiwan Wants To Know

Taiwan is plugging away at construction of its new, homemade submarines. The first of a planned eight indigenous submarines could join the Republic of China Navy as early as 2024. In the meantime, the navy is struggling to rearm its existing pair of combat-capable subs.

The extenuated effort to acquire American-made torpedoes for the two 1980s-vintage boats underscores the difficulty the Taiwanese navy has faced in sustaining any undersea capability—to say nothing of keeping pace with the Chinese navy’s own growing and increasingly modern sub fleet.

The ROCN submarine fleet includes two boats based on the Dutch Zwaardvis class that Taiwan acquired in 1987 and 1988, plus two U.S.-made Tench– and Balao-class boats that Taipei bought in 1973.

The latter two boats date from the mid-1940s. Hai Shih and Hai Bao are the oldest submarines in the world and, while lovingly maintained, are all but useless in combat. The ROCN mostly uses them for training.

As long ago as the late 1980s, Taiwan began exploring the possibility of a follow-on submarine acquisition. But China leaned on the world’s sub-builders, threatening sanctions against any country that sold Taiwan new boats.

Finally, in 2015, the Taiwanese government lost patience. China was a decade into a major naval buildup and the ROCN’s existing submarines weren’t getting any less ancient. Taipei began cutting deals with American and Japanese suppliers for the major technologies Taiwanese shipbuilder CSBC would need to equip the new boats.

On Nov. 24 last year, dignitaries gathered at CSBC’s new submarine factory in Kaohsiung to mark the start of production. “Proud to launch our #MadeInTaiwan submarine program,” Taiwanese President Tsai Ing-wen tweeted.

A year later, the $1.8-billion boat is coming together. Construction could wrap up in 2023, at which point the sub will begin sea trials, a prerequisite for handover to the fleet. That means that, for at least another three years, the two 40-year-old Dutch-made boats will represent the ROCN’s entire front-line sub force.

But it’s unclear how hard Hai Lung and Hai Hu can fight. The boats might lack reliable weapons in adequate numbers. The deal Taiwan cut with The Netherlands back in the ‘80s reportedly didn’t include the German-designed AEG SUT 264 wire-guided torpedoes that were standard on Zwaardvis-class boats.

Taiwanese officials shopped around for a torpedo-supplier and eventually found one—Indonesia, which has a license to produce SUTs. Taiwan traded cash, landing craft and rice for around 200 torpedoes. Sometime apparently in the late 1980s, the ROCN organized its first live fire of the munition. The SUT worked as advertised.

Over the next two decades, however, Taiwan’s torpedoes fell into disrepair. In 2003, the navy after a couple failures finally managed to hit a target vessel with a SUT. “It has helped us regain self-confidence,” Adm. Miao Yung-ching said. “It will also make the public have confidence in us again.”

But that confidence was temporary. It was another 13 years before the ROCN again successfully tested a SUT. A few months later in April this year, an Indonesian submarine suffered an explosion while performing drills with SUT torpedoes. All 53 people aboard died.

It’s apparent the Taiwanese fleet no longer can count on the ancient SUTs. It’s possible the two Dutch-made submarines’ only effective weapons right now are the 32 Harpoon anti-ship missiles the ROCN ordered from the United States back in 2008.

In 2017, the U.S. State Department cleared Taipei to acquire up to 46 Mark 48 torpedoes, which are the same diameter as the SUTs but much more modern—and include an optional autonomous mode requiring no guidance wire.

The Mark 48s were supposed to arrive by 2028 but the Taiwanese government, obviously worrying about the SUTs, reportedly has asked for delivery in 2026. This year the ROCN began a $26-million program to upgrade Hai Lung and Hai Hu in order to prolong their service lives through 2030 while also making them compatible with the American weapons.

It’s clear the fleet is going to need more torpedoes. The Mark 48s on order are adequate to fully arm Hai Lung and Hai Hu. But demand for munitions is going to grow, and fast, once the new boats start joining the fleet in a few years’ time.