US and South Korean sources have claimed that North Korea is building a tube capable of firing a submarine-launched ballistic missile (SLBM), a move that could potentially give Pyongyang a second strike nuclear capability.
US officials disclosed to the Washington Free Beacon in late August that “a missile launch tube on a North Korean submarine was recently observed by US intelligence agencies”. On 14 September South Korea’s Ministry of National Defense (MND) confirmed that North Korea may be building a SLBM-equipped submarine.
In a written response to queries from an opposition lawmaker the MND stated: “There is no intelligence that North Korea has an SLBM in operation. But the possibility of a North Korean submarine equipped with an SLBM has been detected recently.”
Neither sources offered any additional details, such as the size of the missile tube or the type of submarine being used by the North Koreans. However the US report cited “two defence officials” as raising concerns about a new “nuclear threat”, which suggests the missile tube may be for a missile large enough to carry a nuclear warhead.
Pyongyang could have exploited two technology sources for a potential “cold-launch” SLBM launch tube. First are the one or more Project 629 ‘Golf’-class conventional missile submarine (SSB) acquired from Russia as scrap in the early 1990s.
While one of these submarines also had a Soviet-era R-27 (SS-N-6 ‘Serb’) SLBM that later aided the development of North Korea’s 2,500 km to 4,000 km-range BM-25 Musudan, Pyongyang would have likely gained insights from its three cold-launch SLBM tubes.
Second, North Korea has developed two new fourth-generation surface-to-air-missiles (SAMs) that very likely use cold-launch tubes. The Pon’gae-5 or KN-06, first seen in 2011, uses a cold-launch tube that may be similar in size to the Chinese HQ-16A SAM. The Pon’gae-6 appears to use a tube closer in size to the Chinese HQ-9 or the Russian S-300 systems.