The Ulsan-class frigates were South Korea's largest domestically built warships before KDX. Concern after the Vietnam War about national self-support and protection pushed the country toward domestic naval capability. Major industrial capacity was already available, but design independence required teams with military and naval expertise. They had to judge which American and other foreign ideas fit Korean waters, the exclusive economic zone, force structure, and strategic needs. The aim was to integrate and modify imported systems around national requirements. The US Constellation frigate program provides a comparison: an intended difference of about 15% from the FREMM parent design became an estimated 15% commonality, or 30% on a generous estimate. Even a capable foreign design can change extensively when another navy adapts it to its missions.
Notable Point · 1:33-4:08
Domestic design teams adapt foreign systems to Korean needs
South Korea already had major shipyards. It still needed naval design teams that could adapt foreign technology to Korean geography and missions.