North Korea’s “nuclear missile” launch submarine spotted in Sinpo dry dock for first time in over 4 years

A “Sinpo-B class” (Gorae-class) submarine capable of launching ballistic missiles (SSB) has recently been moved into a dry dock in North Korea, and is believed to be undergoing repairs or modifications. The submarine is known as the “8.24 Hero Ship,” a test platform for submarine-launched ballistic missiles (SLBMs).

According to 38 North, a United States-based outlet operated by the Stimson Center specializing in North Korea, analysis of recent satellite imagery of the Sinpo shipyard indicates changes since last month in the movements of the 8.24 Hero Ship, which had typically remained at its mooring site or been observed near the “Sinpo-C class” strategic submarine (Kim Kun-ok Hero Ship).

North Korea previously claimed it successfully launched the “Pukguksong-1” SLBM from the 8.24 Hero Ship on Aug. 24, 2016. However, the submarine is not considered operationally capable of carrying SLBMs; instead, it is classified as a test platform equipped with a launch tube for experimental missile launches after submerging. North Korea also launched a new SLBM from the submarine in 2021.

The Kim Kun-ok Hero Ship, unveiled in September 2023 as the country’s “first tactical nuclear attack submarine,” is regarded as a platform capable of carrying SLBMs during normal operations. While the 8.24 Hero Ship is viewed as a test platform for verifying missile launch technology, the Kim Kun-ok Hero Ship is assessed as a step in the evolution of North Korea’s strategic submarine capabilities toward operational deployment.

According to 38 North, satellite imagery taken on the 6th did not clearly identify the location of the 8.24 Hero Ship, but images from the 15th confirmed the submarine inside a dry dock. Although the hull was covered with camouflage netting, partially exposed structures matched the Sinpo-B class, estimated to be about 68 meters in length.

This marks the first time the 8.24 Hero Ship has been observed in a dry dock since October 2021, shortly after an SLBM launch. At the time, it was believed the vessel had sustained damage during the launch process and underwent repairs. This time, however, there is speculation that modifications may be underway to install a launch tube capable of firing a new SLBM.

38 North noted that no significant signs of an imminent SLBM launch have recently been detected in the Sinpo area, suggesting the submarine may simply be undergoing routine maintenance.