North Korea is reportedly building two new covered docks (pens) that could be used to protect ballistic missile submarines (SSBs).
According to IHS Jane’s, Airbus Defence and Space satellite imagery indicates that construction of the base for the SSBs near Sinpo in North Korea started between August 2009 and November 2012.
The new findings reveal that the base is located 2.25km south of the Sinpo shipyard, close to the Mayang-do Naval Base on the country's east coast.
Commercial satellite imagery analysis from IHS Jane's Defence Weekly stated that a 6,000m² area had been blocked off by a sea wall and was filled by November 2012 using spoil from the surrounding hills as material.
The imagery also suggests that each of the two pens are believed to approximately 150m in length, which can accommodate two 67m-long SSBs.
North Korea currently has one SSB that houses one ballistic missile launch tube and was used to test Pukgeukseong (Polaris) submarine-launched ballistic missiles.
The SSB is referred to as belonging to either the Sinpo or Gorae class.
IHS analysis suggests that the covered pens would improve North Korea’s strategic deterrent as they could make it harder for other countries to track the number of SSBs are at sea at any given time.