South Korea has ordered another six German designed Type 214 submarines. Nine years ago, South Korea ordered three 214s, and the first of those entered service last year. The boats are built in South Korea, using licensed technology from the German developer (HDW).
Three years ago, the South Koreans dropped plans to built several large, 3,000 ton, diesel-electric subs. But now, this plan has been revived. But first, the six additional 1,600 ton Type 214 subs will be built over the next 14 years, in addition to the three already planned. South Korea already has nine 1,100 ton Type 209 subs, designed and built in Germany.
The Type 214 boats use fuel cells, enabling them to stay underwater for up to two weeks. The South Koreans like their 209s, but looked at a competing offer for the French Scorpene. are now getting nervous because the first 214 recently received by Greece, had a long list of problems. The Type 214 is a 1,700 ton, 202 foot long boat, with a crew of 27. It has four torpedo tubes and a top submerged speed of 35 kilometers an hour. Maximum diving depth is over 1,200 feet.
The two designs are similar, with the Scorpene being more recent (and the result of cooperation between a French and a Spanish firm.) The Scorpene is a little heavier (1700 tons), has a larger crew (32) and is a little faster (37 kilometers an hour). It has six 21 inch torpedo tubes, and carries 18 torpedoes and/or missiles. Both models are usually equipped with an AIP (air independent propulsion) system. This enables the sub to stay under longer, thus making the sub harder to find.
With well trained crews, 214s and Scorpenes can get close to just about any surface ship, no matter how good the defenders anti-submarine defenses are. But it's the AIP boats that are the real killers. Without AIP, subs spend most of their time just below surface, using their diesel engines (via a snorkel device that breaks the surface to take in air, and get rid of the engine exhaust.) Snorkels can be spotted by modern maritime patrol aircraft, and many nations are getting more of these.
European built AIP boats go for about half a billion dollars each. The second batch of South Korean 214s will have an improved AIP system, which is apparently more reliable, and provides a small increase in time underwater.