What Is Hero Kim Gun-Ok? Analyst Dissects North Korea’s New Nuclear Submarine

North Korea has likely begun rebuilding its submarines into more lethal weapons, an analyst has said.

North Korea launched its first modernized submarine, the Hero Kim Gun-Ok, on September 8, 2023, with ten missiles in vertical launch tubes, likely four ballistic and six cruise, according to open-source analyst H.I. Sutton writing in his publication Covert Shores.

The development comes as North Korean leader Kim Jong Un has sent ominous warnings to the U.S. and South Korea as tensions have escalated on the Korean Peninsula. It reflects North Korea’s continued focus on expanding and diversifying its military capabilities, indicating a strategic emphasis on enhancing its naval strike capacity.

NK News, a specialist publication focusing on North Korea, reported last year that North Korea launched its Hero Kim Gun-Ok submarine on September 6, 2023.

“In his speeches at the vessel’s launching ceremony on Wednesday and an onboard inspection on Thursday, Kim expressed satisfaction that the country has acquired its own nuclear attack submarine to counter the advanced naval assets of the US, KCNA said,” Reuters reported September 8, 2023, citing North Korean state media.

This submarine represents an upgrade in North Korea’s maritime strategic arsenal, equipped with a total of ten missiles housed in vertical launch tubes, according to Sutton’s analysis. The armament likely comprises four ballistic and six cruise missiles, nestled under a distinctive turtle-back structure extending beyond the sail, marking a notable advancement in the country’s military technology.

The missiles aboard the Hero Kim Gun-Ok are modern and considered generally reliable, with the potential capability to carry nuclear warheads. This development underscores North Korea’s ongoing efforts to bolster its offensive capabilities, posing a strategic threat primarily aimed at South Korean or Japanese cities and key military bases, according to Sutton.

“The new role is likely strategic strike against South Korean or Japanese cities and key bases. The exact types of missiles have not been confirmed. But we can deduce that the ballistic missile is the KN-23 Hwasong-11S. This short-range ballistic missile (SRBM) flies on a quasi-ballistic trajectory. The family is generally reported to have a maximum range of 690 km, although specifications for the submarine-launched variant are not available,” Sutton wrote.

The cruise missiles equipped on the Hero Kim Gun-Ok are speculated to be either the “Pulhwasal-3-31” or “Hwasal-2,” or possibly a combination of both. These missiles, likened to American Tomahawk or Russian Kalibr missiles, have been tested repeatedly, with the Pulhwasal-3-31 observed being launched from a submarine’s torpedo tube in past tests, Sutton wrote.

The introduction of the Hero Kim Gun-Ok marks a departure from the modified Romeo Class boat, Sinpo-C, which is thought to have been adapted to carry two or three larger SLBMs.

This suggests that North Korea is developing a mixed fleet of missile submarines, with the Sinpo-C class focusing on strategic missiles and those in the class of the Hero Kim Gun-Ok serving a more tactical role, Sutton wrote.