Successful Localization of Jangbogo-III: 'Now It's Time for Export'

[Lee Jeong-il, Defense Acquisition Program Administration, Korean Submarine Project Group, System Development Team 1] In December last year, the combat system and sonar system for the Jangbogo-III submarine were reviewed by the Defense Acquisition Planning and Management Subcommittee, and the establishment of the national defense standards was completed. These two weapon systems, designed and built using domestic technology, are installed on the 3,000-ton Jangbogo-III Batch-I first ship, Dosan Ahn Changho, which is currently undergoing testing and evaluation, and are scheduled to be delivered to the Navy in early 2021.

Since the project method was decided in 2005 to independently design and build the Jangbogo-III Batch-I submarine domestically, a review was conducted on "how to acquire the submarine’s core weapon systems, the combat system and sonar system." The existing Jangbogo-I class (Type 209) and Jangbogo-II class (Type 214) submarines operated by the Navy were equipped with combat and sonar systems made abroad. However, to "acquire systems that reflect the operational tactics of our Navy’s submarines and reduce maintenance and operational costs," it was decided to develop the Jangbogo-III combat and sonar systems domestically. Development began in 2009 and continued for about 12 years until system development was completed in 2020, and now deployment is imminent.

▲ Jangbogo-III Combat System = The combat system is a core weapon system that integrates and processes target information acquired through various sensor systems and tactical data link systems installed on the submarine, performing battlefield situation monitoring, command decision-making, weapon control, engagement support, and navigation support for the submarine, thus serving as the "brain of the submarine." In particular, it ensures high reliability and system stability so that it can operate continuously from the submarine’s departure to arrival. Since it is equipment used continuously by the crew 24 hours a day, much attention was paid to user convenience and design aspects such as display configuration. During development, frequent visits to submarine units were made to collect and reflect the opinions of actual users, the submarine crew, in the design.

Also, to efficiently utilize the limited space characteristic of submarines, multifunction consoles (combat and sonar system control devices) were developed to maximize installation and space utilization while fitting Korean body standards. The multifunction console developed in this way is now used as the standard model for all combat systems developed thereafter.

Furthermore, for the first time in ship projects, commercial standard parts were widely used, and software tools ('SMART') for managing discontinued parts were employed to effectively prevent obsolescence and respond to discontinuations by equipping the latest information and communication components.

Regarding software, an international standard open architecture (OA) was adopted to allow flexible integrated design even when software changes occur between devices. To ensure survivability and reliability, key components were designed with redundancy, and a fully distributed system was designed to process large amounts of information in real time.

For maintenance convenience, online monitoring functions were incorporated down to the minimum replacement unit equipment to enable immediate fault detection. Cabinets and consoles were designed with rotating racks that allow maintenance by opening only part of the front of the equipment without disassembling the entire device, thereby improving maintenance ease and reducing repair time.

▲ Jangbogo-III Sonar System = The sonar system is a weapon system that uses sound waves underwater, where radio waves cannot reach, to detect and analyze various sound sources, serving as the "eyes and ears of the submarine."

The sonar system consists of 'active sonar,' which detects signals reflected back from targets after sound waves are emitted from the submarine, and 'passive sonar,' which detects sound sources generated by targets. At the start of development, the Agency for Defense Development only had experience developing passive sonar for surface ships, and only about ten countries worldwide had independently developed and operated submarine sonar systems. Especially, advanced submarine-developing countries such as the United States, the United Kingdom, and France monopolized sonar-related technologies and restricted the export of related core technologies. Therefore, developing a total of eight types of active and passive sonar domestically and achieving the required performance when installed on the ship was a significant technical challenge.

Thus, for the first time in domestic ship projects, underwater explosion shock tests were conducted on components installed outside the submarine to preemptively eliminate potential risks during development. A separate submarine model was produced and installed on a towing barge to conduct about five months of sea trials, securing reliability for submarine installation.

Digital mock-ups were also performed to ensure that various sensors, towing winches, and cabinets could be installed in the confined space of the submarine without interference with other equipment. Nevertheless, unforeseen issues during actual ship installation were addressed by supplementing installation manuals, inspection lists, and procedures to be utilized in future mass production projects.

In terms of performance, compared to existing systems in operation, detection performance and bearing/range accuracy were improved, and the detection frequency was more than doubled. Additionally, a mine avoidance hydrophone was added to enhance underwater mine and obstacle detection, navigation support capability, and operational convenience.

Core function software was developed with redundancy and distributed system design to minimize system failures and enable smooth operation during long underwater missions.

Through this process, the combat and sonar systems installed on the Jangbogo-III Batch-I Dosan Ahn Changho were subjected to about two years of integration tests with other systems and sea trials. During the evaluation period, improvement work was carried out in parallel to better satisfy operator requirements. Identified improvements were reflected in subsequent mass production to ensure that more advanced systems are delivered to the user forces.

Moreover, the localization rates of the combat system and sonar system are over 95% and 85%, respectively, achieving cost reductions in equipment acquisition and operation and maintenance that had previously relied on overseas imports. Despite many difficulties in conducting tests and evaluations due to the COVID-19 pandemic, the localization of many components allowed most problems to be resolved without support from overseas companies, reaffirming the importance of domestic core system development.

This development success was an opportunity to accumulate technology and development experience for many domestic partner companies, including the Agency for Defense Development and prototype companies such as Hanwha Systems and LIG Nex1. It is expected to contribute to the future expansion of exports of domestically produced weapon systems.

This content was produced with the assistance of AI translation services.