"An Chang-ho Submarine and 11 Years of Shared Hardship" [Yang Nak-gyu's Defence Club]

Captivated by Submarines, Jung Minjae Becomes Korea's First Female Naval Inspector
From Designing the Ahn Changho Submarine to Overseeing Its Safety Inspections

In the 1970s, South Korea faced a tremendous security crisis. The United States, advocating the "Nixon Doctrine" which stated "you must defend your own security," withdrew one ground division of the U.S. Forces Korea and even attempted to pull out all U.S. troops stationed in South Korea. However, our military was still unable to properly manufacture even a single rifle after the Korean War. On December 26, 1971, former President Park Chung-hee delivered a top-secret memo to the Agency for Defense Development (ADD). The project was disguised under the name "Directive to Establish an Aviation Industry Promotion Plan." Starting with this project, our military achieved the development of domestically produced missiles, tanks, and aircraft. The first generation of Korea’s defense industry led the development of domestic weapons. Now that domestic weapons have been operationalized, the second generation of the defense industry is taking charge of maintenance, repair, and overhaul (MRO). We met with those who are active in the MRO market following defense exports.

Jung Min-jae, Senior Inspector at Korean Register (KR). She is the first female ship inspector in Korea who inspects the Navy’s surface ships and submarines. Ships undergo safety inspections to maintain combat readiness during operation, and Jung is responsible for these inspections. Over 50 surface ships and 8 submarines of the Korean Navy have passed through her hands. She personally inspected the 200-ton class small submarine "Dolgorae," the first small submarine introduced by the Korean Navy. Korean Register is the only internationally accredited inspection agency in Korea registered with the International Association of Classification Societies (IACS). Only 12 countries worldwide are registered with IACS. Korean Register holds government-delegated inspection authority to inspect ships from over 80 countries. It also establishes ship design and construction standards necessary for ship design. In the 1980s, our ships were built according to U.S. standards. Since then, Korean Register has developed "Korean-style design standards" tailored to the maritime operational environment of the Korean Peninsula.

Jung Min-jae, Senior Inspector at Korean Register (KR), is the first female ship inspector in Korea who conducts safety inspections on our Navy's surface ships and submarines. (Photo by Korean Register)

Jung’s connection with ships dates back to 2003. Having studied naval architecture and ocean engineering in university, she was captivated by submarines. Jung recalled, “When I opened my university diary, it was filled with dreams about submarines and icebreakers,” adding, “Although submarines are invisible, I believed they were the most powerful weapon to maintain peace.”

Captivated by Submarines Since University, Joined ADD

An earnest wish brought an opportunity. In 2009, as soon as a recruitment announcement was made by the Special Ship Research Center at the Agency for Defense Development (ADD), she applied immediately. ADD was independently designing a 3,000-ton class submarine using domestic technology. This was the secret project for the Dosan Ahn Changho-class submarine (KSS-III). Building a ship proceeds in three stages: basic design, detailed design and lead ship construction, and follow-up ship construction. There is also a "concept design" stage before basic design, which is for setting the ship’s concept and determining requirements. She enjoyed working overnight on research, proud to be able to directly design the submarine she had long desired. Three years later, the basic design was completed, but her affection for submarines did not fade.

Continuing the Bond with Ahn Changho Submarine at Korean Register

Jung said, “Although my connection with the Ahn Changho submarine ended, it never left my mind. I earnestly wanted to be involved until it was delivered to the Navy.” The place she chose was Korean Register, which was involved in the detailed design, construction, construction inspection, and sea trials of the Ahn Changho submarine. Upon joining, the company selected employees for dispatch to Geoje Island, where Hanwha Ocean (formerly Daewoo Shipbuilding & Marine Engineering) was building the Ahn Changho submarine. Jung was the first to apply.

Prosecutor Jeong Min-jae spent 11 years working closely from the design to the sea trials of the Ahn Chang-ho-class submarine. (Photo by Korean Register)

The hands-on field experience was different from her enthusiasm. To participate in the Ahn Changho-class submarine’s submersion, she had to undergo submarine escape training. About 50 people, including defense industry employees, participated in the training. Gritting her teeth, she underwent underwater escape training at a depth of 10 meters. Only 24, including her, passed. Despite the tough training, opposition from those around her continued. Ships were considered a male-only zone. Submarines lacked separate female spaces such as bedrooms and restrooms. At that time, a senior colleague who was not in good health strongly recommended her.

Boarding the Male-Only Zone Submarine Despite Opposition

In June 2019, she began her first submersion. There were days when she did not see sunlight for as long as 4 nights and 5 days underwater. Grueling sea trials followed. She endured test dives (TDD) that checked pressure at the deepest parts of the sea, as well as emergency surfacing tests. In total, she endured 100 days of submersion. She spent 11 years working closely from the design to the sea trials of the Ahn Changho-class submarine. Although people around her repeatedly said, “Thank you for your hard work,” what comforted her most was the Ahn Changho submarine itself.

In August 2021, she will never forget the day the Ahn Changho submarine was handed over to the Navy. Jung said, “Watching the Ahn Changho-class submarine being embraced by the Navy on the sea felt like a parent sending off their child in marriage,” adding, “I could only promise to meet again for safety inspections.”

Now Studying Nuclear-Powered Ships

The American Bureau of Shipping (ABS) conducts regular inspections of the U.S. Littoral Combat Ship (LCS) and Zumwalt-class destroyer (DDG-1000). The Lloyd’s Register (LR) in the UK mandates regular inspections for destroyers including the Queen Elizabeth aircraft carrier. The French Bureau Veritas (BV) and Norwegian DNV do the same. The National Assembly is preparing legislation to entrust inspections of our ships to professional organizations rather than state agencies or the owning military. This is because regular inspections are essential for operating in foreign waters during joint exercises.

Jung is currently preparing for the future. Shipyards worldwide are developing nuclear-powered commercial vessels, and she aims to keep up with this trend. Although she has already completed her master’s and doctorate degrees in naval architecture and ocean engineering, she applied again for a master’s degree in nuclear systems engineering. Last year, she even applied for a patent for a welding method capable of welding high-density polyethylene (HDPE), a plastic material. It is the first welding method of its kind in Korea. Jung firmly stated, “Inspectors should not just inspect according to the design.” She added, “They must be able to propose technical alternatives suitable for various conditions. That is what future ship inspectors are.”