SEOUL, SOUTH KOREA — North Korea has acquired a Soviet-era decommissioned submarine and has modified it to be able to fire ballistic missiles, South Korean government sources told a local news agency on Sunday, just weeks after an unidentified submarine was spotted in satellite imagery.
The Yonhap news agency, citing military and government sources in South Korea, said the North's newly-acquired submarine was built in 1958 and decommissioned in 1990, but it is unknown which country provided the vessel. "[The North] imported a Soviet-era Golf-class diesel submarine and modified it," a source told Yonhap.
The vessel was first discovered last month when the U.S.-Korea Institute at SAIS (USKI) analyzed satellite imagery of North Korea's submarine bases and building shipyards. A satellite image of the Sinpo South Shipyard, which is located on the country's east coast, revealed a new submarine approximately 67 meters (219.8 feet) long with a beam of 6.6 meters (21.6 feet).
Yonhap, citing its unidentified government sources, described the new vessel as a 3,500-ton Golf II class submarine carrying an R-21 submarine-launched ballistic missile (SLBM), which is a single-stage, liquid-propellant missile with a 1,180-kilogram (2,601-pound) warhead and has a maximum range of 1,420 kilometers (882 miles).
Another source said North Korea had already carried out dozens of tests on the ground and at sea to mount a missile tube on the new vessel, but more tests will be required to perfect the technology. "A ground test facility for the SLBM launch has been up and running at the Sinpo shipyard," the source was quoted as saying.
Joseph Bermudez Jr., an expert in ballistic missile development at the U.S.-Korea Institute, said a recent review of satellite imagery confirmed the existence of a new test stand at the Sinpo South Shipyard, which is also home to the headquarters of North Korea's Maritime Research Institute of the Academy of National Defense Sciences.
"The new installation is the right size and design to be used for the research, development, and testing of the process of ejecting a missile out of a launch tube as well as evaluating its compatibility with submarines and surface combatants as well as the missiles themselves," Bermudez said.
The ballistic missile expert, reporting for the Institute's 38 North website, said it would likely take years for North Korea to design, develop, manufacture, and deploy an operational submarine-launched ballistic missile force. He said the potential threat of such a capability should not be ignored, but cautioned against the threat being exaggerated.
"While the development of submarines carrying ballistic missiles could provide North Korea with a survivable second-strike nuclear capability, aside from the technological challenge, it also assumes that Pyongyang would entrust an operational nuclear-armed missile to the captain of a submarine who would, in time of war, most likely be out of communication with the leadership," Bermudez explained.
North Korea is believed to have around 70 submarines, most of which are equipped with outdated weapons. The North is accused of using a midget submarine to fire a torpedo at a South Korean Navy ship in March 2010, killing 46 people. And while a South Korean-led international investigation blamed a North Korean submarine, the North insists it was not responsible for the unexpected attack.