In the early 1980s, South Korea began developing and building its own FFX series of frigates. The first ones were nine 2,200-ton Ulsan-Class ships. These entered service between 1981 and 1992. Each ship served about three decades before being retired. These ships had a crew of 186 and were armed with two 76mm cannon, as well as three or four 30-40mm autocannon. Each ship carried eight Harpoon anti-ship missiles. There were six torpedo tubes for lightweight ASW (anti-submarine warfare) torpedoes along with twelve depth charges,
In 2013 the first of six 3,200-ton Incheon-Class ships entered service. The others entered service between 2014 and 2016. Each ship is expected to serve about three decades before being retired. All are still in service. These ships each have a crew of 140 and are armed with a 127 mm cannon, as well as missile defense systems consisting of a 20mm Phalanx autocannon and a longer-range RAM missile system. There are six ASW torpedo tubes and eight South Korean anti-ship missiles as well as six South Korean land attack versions of these missiles. Both have a range of about 200 kilometers. In the rear of the ship is a flight deck for a helicopter as well as a hangar.
The Inchon-class ships were joined in 2016 by eight 3,900-ton Daegu
-class frigates. All of these entered service by the end of 2023. After that a new class of six 4,300-ton Chungnam-class frigates are being built. The first of these is to enter service in 2024. These two classes of frigates have the same armament as the Inchon-class but have better electronics and sensors that are operated from a novel integrated mast.
All these frigates are highly automated, requiring a crew of only 140. Top speed is 55 kilometers an hour while range is 8,300 kilometers if cruising at 33 kilometers an hour. Most of the equipment (including electronics) and weapons are locally built. South Korea plans to build as many as 24 FFX series frigates at a cost of $200-300 million each. South Korea plans to export the FFX to many navies who want high quality, low cost, warships. Meanwhile, South Korea has also developed a slightly larger FFX II frigate and subsequent FFXs will be this version. But for export customers South Korea will make smaller versions as it has already done for the Philippines. This approach was pioneered by European shipyards and later adopted by Russia. One size does not fit all, and the customer is always right because they are paying for it.