In June South Korea launched the first of its FFX II frigates. This one will enter service in 2018. These are a slightly heavier version of the original FFX, which entered service in 2013. Six of these are being built (by 2017) followed by a dozen or more FFX II. The new FFX II has hybrid electric drive system (the first for Korean warships). This makes the FFX II quieter and more difficult for submarine sonar to detect. FFX II also has Korean designed VLS cells.
The original FFXs are 3,500 ton ships and are each armed with a 127mm gun, eight anti-ship missiles, six torpedo tubes, plus two RAM launchers, two Phalanx systems, 16 anti-aircraft missiles and a hangar for one helicopter. The ships are highly automated, requiring a crew of only 120. Top speed is 61 kilometers an hour and range is 8,000 kilometers. Most of the equipment (including electronics) and weapons are locally built. The first ship in the class, the Ulsan, cost $260 million. South Korea hopes to export the FFX to many navies who want a quality, low cost, warship.
South Korea equips FFX with American Phalanx Block 1B systems to protect their ships from anti-ship missiles. Each Phalanx consists of a six barreled 20mm cannon and radar all programmed to automatically fire at any rapidly approaching object. FFX is also equipped with a box launcher containing 21 SeaRAM missiles. SeaRAM is basically the Phalanx system with the 20mm gun replaced with a box of RAM (RIM-116 "Rolling Air Frame") missiles. The Phalanx was developed in the 1970s, and entered service in 1977. RAM was developed in the 1980s, and didn't enter service until 1993. RAM has a longer range (7.5 kilometers) than the Phalanx (two kilometers) and was originally designed to be aimed using the ship's fire control systems (which can detect incoming missiles more than ten kilometers away). Phalanx has its own radar and fire control system and once turned on will automatically fire at any incoming missiles. This was necessary, as some anti-ship missiles travel at over 500 meters a second. With SeaRAM, you've got a little more time, and can knock down the incoming missile farther from the ship. This is important, because it was feared that a large, very fast anti-ship missile (which the Russians prefer, and sell to foreigners), even when shot up by Phalanx, might still end up having large parts of it slam into the target ship. Since SeaRAM has eleven missiles ready to fire, it can also engage several targets at once, something the Phalanx could not do.
Some navies, like South Korea, use Phalanx and RAM, to provide a dual layer of defense on some ships. Any missiles that get past RAM, then have to get past Phalanx as well. Phalanx uses 20mm depleted uranium shells, to slice through incoming missiles. Phalanx fires shells at the rate of 75 per second. The Phalanx radar can pick up targets five kilometers away.
The RAM missiles are 127mm in diameter, three meters (9.3 feet) long and weigh 73.6 kg (162 pounds) each. The terminal guidance system is heat seeking. Basically, it uses the rocket motor and warhead from the Sidewinder air-to-air missile, and the guidance system from the Stinger shoulder fired anti-aircraft missile. SeaRAM missiles cost about $450,000 each. SeaRAM is meant to provide protection for combat support ships that normally have no defenses, or at least no combat radars and fire control system.
The ample anti-missile systems are considered essential for the FFX because the most likely foe is North Korea, which has lots of older anti-ship missiles fired from patrol boats as well land based launchers.