A South Korean navy ‘Son Won II’ submarine.
South Korea’s got some weird submarines. And they’re about to get weirder … and more powerful.
As part of a sweeping, five-year defense plan costing $250 billion, Seoul plans to develop a new class of attack submarine carrying non-nuclear ballistic missiles.
Conventional ballistic missiles are a rarity on submarines. For land-attack missions, most navies arm their undersea boats with cruise missiles, as cruise missiles are more accurate—albeit slower and less powerful—than ballistic missiles are.
But Seoul has some, ahem, unique defense needs owing to the presence on its border of a heavily-armed and belligerent nuclear state. South Korea’s submarines and their hard-hitting ballistic missiles give the country some ability to prevent a North Korean attack.
The South Korea fleet boasts an impressive 16 submarines, with more on the way. There are eight Jang Bogo-class vessels—variants of the German Type 209—plus nine Son Won IIs based on Germany’s Type 214.
A new class is under construction. At around 3,600 tons of displacement, the four Dosan Ahn Changhos each is around twice as large as the older submarines are. That extra displacement makes room for vertical-launch tubes that are compatible with cruise missiles and ballistic missiles.
The South Korean defense ministry since the 1980s has been developing the Hyunmoo ballistic missile for non-nuclear attacks. A land-based version already is in service. A naval version with a range as far as 500 miles is in the works. As many as six of the submarine-launched ballistic missiles could fit in a Dosan Ahn Chanhgo.
The SLBMs are for short-notice “kill chain” attacks on North Korea’s own ballistic missiles. “Should a [North Korean] attack become apparent, kill chain calls for the employment of strike assets to destroy North Korea’s nuclear, missile and long-range artillery facilities,” the Washington, D.C. Center for Strategic and International Studies noted.
If South Korean intelligence detected North Korean rockets deploying, perhaps for a nuclear strike, Seoul’s submarines could attack—preemptively.
A Hyunmoo-2 test launch in 2017.
“The SLBM may lack the accuracy of the [submarine-launched cruise missile], which is equipped with a [sophisticated] guidance system,” retired South Korean navy rear admiral Kim Hyeok-soo said. But “its velocity and destructive capability are significantly greater.’
“The deployment of the speedy and stealthy SLBM will allow the South Korean navy to deliver a blow to North Korea before the situation even escalates to emergency levels,” Kim explained.
So important is this kill-chain doctrine to South Korea that the government is doubling down on it. The new five-year defense plan includes another submarine class with even greater rocket-capacity than the Dosan Ahn Chanhgo has.
“We have in mind 3,600- and 4,000-ton submarines for development, much more advanced than the ones in operation now,” a senior defense ministry official told The Korea Herald.
The first Dosan Ahn Chanhgo is on track to commission in 2022. The new, larger submarines could follow in the late 2020s.