Quick Take: North Korea’s Sinpo-B Class Submarine Drydocked
This article was updated on April 22 and April 24, 2026 with new imagery.
On commercial satellite imagery of North Korea’s Sinpho South Shipyard, it appears that the Sinpo-B class (GORAE) ballistic missile submarine (SSB) (8.24 Yongung) is probably in the drydock, likely undergoing repairs or modifications.
The submarine is usually berthed in the secure boat basin, sometimes alongside the larger Sinpo-C class SSB (Hero Kim Kun Ok) under the covered area along the quay. On imagery from March 29, it had been moved to the north wall. By April 6, it was no longer against the north wall, but the imagery angle precluded the ability to determine if it was back alongside the Sinpo-C SSB under the protective awning or elsewhere. Due to imagery angles and low resolution, its location in subsequent imagery could not be determined.
On imagery from April 15, however, it appears that the Sinpo-B SSB is in the drydock, although covered with netting that obscures it from view. Measurement of the few key points that can be seen through the covering indicate the vessel in question is approximately 68-meters-long, which is within the range of the Sinpo-B and significantly shorter than the Sinpo-C and Romeo-class SSBs.
The last time the Sinpo-B SSB had been drydocked was after an at-sea ballistic missile launch on October 19, 2021. Following that launch, which apparently damaged the submarine, repair work was done on its sail, which contains the submarine’s sole missile launch tube, in the secure boat basin. However, by early December 2021, the submarine was moved to the drydock likely for further repairs or maintenance. Why it is currently in the drydock is unclear, as no at-sea ballistic missile launches have been detected or reported. It is possible that after four years of being berthed in the secure boat basin, hull cleaning was needed or further modifications or repairs are underway.
At the construction hall, the cargo vessel previously reported as being stripped down appears to be now fully inside the building. The purpose of this activity is still unclear.
Imagery from April 22, 2026 reveals the netting has been removed, confirming that the Sinpo-B Class SSB is in the drydock. It is likely that the vessel is being worked on in some capacity, though the nature of this activity still remains unclear.
By April 24, the Sinpo-B SSB was positioned back in the secure boat basin alongside a support vessel. The nature of the work conducted on the vessel is unknown, however took place over a short period of time.
