Republic of Korea Navy's last upgrades on Chang Bogo Class attack.

Republic of Korea Navy currently operates 9 Chang Bogo-class (modified German Type 209) submarines acquired between 1993 and 2001. These submarines are being upgraded during scheduled overhaul period to improve their capability and to extend their service life.

Republic of Korea (ROK) Chang Bogo Type 209/1200 submarine Nadaeyong (SS 069) surfacing during a SINKEX for Rim of the Pacific RIMPAC 2002 (Picture source: )

Chang Bogo Class attack submarines are in service with the Republic of Korea Navy (ROKN). The class is a South Korean license-built version of the German Type 209-1200 Class. Originally developed by Howaldtswerke-Deutsche Werft (HDW), the Chang Bogo Class is built by Daewoo Shipbuilding and Marine Engineering (DSME).

ROK Navy's upgraded Chang Bogo-class submarine is the world's first Type 209 submarine to be equipped with a towed array sonar system. Introduction of TASS remarkably improved the submarine's ASW and shallow water operation capabilities.

Chang Bogo-class submarines were originally equipped with German ATLAS ISUS-83 combat management system, which is outdated by today's standard. The old CMS was replaced with an indigenous model developed by LIG Nex1, which greatly improved the submarine's data processing, storage, and analysis capacity. New algorithms for signal/data analysis and target movement prediction were also developed and integrated.

Integration of new CMS with existing sonar, navigation, communication, armament, and other subsystem was carried out without issue; it was able to maximize the performance of these systems further than before thanks to improved processing, analysis, and tracking capability. Torpedo guidance, which used the analogue method, was also improved by the new indigenous guidance and signal processing algorithm. Multiple torpedos can now be launched simultaneously at a target.

New CMS also open doors for simplified modification and maintenance in the future.

Rendering of new upgraded elements (Picture source: Republic of Korea Armed Forces)

About the Chang Bogo Class:

The Chang Bogo Class incorporates a single hull design from the Type 209/1200. The submarines are designed to perform low-noise operations. Each submarine is fully equipped with automated systems, to reduce the workload of the crew.

The submarine has a length of 56m, a beam of 6.2m and a draft of 5.5m. The submerged displacement of the ship is 1,285t. The Chang Bogo Class submarine can complement 33 crew members.

The Chang Bogo-class submarines are armed with eight bow 533 mm (21 in) torpedo tubes and fourteen torpedoes. The ships are also armed with Sub-Harpoon missiles and can be armed with 28 mines in place of torpedoes and Harpoon missiles. The class is armed with SUT - Surface and Underwater Target Torpedoes.