According to satellite images taken earlier this month, North Korea’s construction of their first fully operational ballistic missile submarine has been progressing at what one U.S. think tank characterizes as an “aggressive schedule.”  The rapid progress would seem to indicate a significant national interest in its completion, as North Korea’s economy continues to struggle under the weight of international sanctions.

According to images takes on November 5^th, North Korea monitor 38 North believes construction is moving ahead on the construction of an operational model of Kim’s previous experimental ballistic missile sub platform.

“The presence of what appear to be sections of a submarine’s pressure hull in the yards suggests construction of a new submarine, possibly the SINPO-C ballistic missile submarine – the follow-on to the current SINPO-class experimental ballistic missile submarine,” 38 North said in a report released on Thursday.

Further analysis of the images also suggests that North Korea is continuing to work the kinks out of submarine-based ballistic missile launches.  Most submarine launched missiles rely on flash-vaporizing high pressure tanks of water to produce what is effectively a steam cannon powerful enough to thrust the missile up beyond the surface of the water, where the missile’s propulsion system can begin to drive it toward its ultimate target.  This is a particularly dangerous method of launch, as a failure in the steam propulsion could result in the missile failing to clear the water, and potentially even falling back down onto the submarine.

“A probable launch canister support, or launch canister, appears to be present within the service tower at the missile test stand suggesting the ongoing ejection testing of submarine launch ballistic missiles (SLBM). Such testing could support the continued development of SLBMs, a new ballistic missile submarine or a combination of both.” 38 North wrote.

The satellite images show two circular objects that appear to be cross sections of a submarine’s hull at North Korea’s Sinpo South shipyard, which has historically been the nation’s submarine building facility.  The first measures at approximately 7.1 meters in diameter while the second tapers down to 6.1 meters, and both possess cross structures that may be used to support decks within the vessel, or possibly equipment.

Although North Korea’s forthcoming ballistic missile submarine will undoubtedly be decades behind America’s fleet of submarines in terms of technological capability, it could still pose a significant threat to American and allied locations in the region.  With what would likely be a single ballistic missile launch tube, North Korea would almost certainly equip the submarine with a nuclear tipped ballistic missile, and although the electric diesel motors that experts anticipate North Korea would employ as a power source are easier to locate and track than modern nuclear submarine propulsion systems, the sheer size of the Pacific could make North Korea’s sub difficult to locate and neutralize in the event of war.

North Korea may intend not to use their ballistic missile submarine as an offensive asset, so much as a deterrent.  As long as it prowls the seafloor in the area, America and its allies could potentially be at risk of a nuclear strike.  The same basic principle has guided American nuclear deterrence strategy for decades via the “nuclear triad;” wherein a breadth of nuclear strike options makes it nearly impossible to neutralize the nation’s ability to respond in the event of an attack.

Image courtesy of North Korean State Owned KCNA