01 Desember 2011
KS-550A Mini-Sub concept for RoKN (all photos : Network54)
South Korea's Agency for Defence Development (ADD) has unveiled an innovative mini-submarine concept - known as the KSS 500A - for the Republic of Korea Navy (RoKN).
The 37 m-long craft is intended to form the basis for a replacement of the two surviving Dolgorae-class mini-submarines, which entered service in the early 1980s. Design work is believed to have started in 2008 and the ADD is now selecting key systems suppliers.
According to a model and accompanying data released at the Marine Week 2011 exhibition in Busan in early November, the KSS 500A has a beam of 4.5 m, surfaced displacement of 510 tons and maximum diving depth of 250 m.
Notably, there are no onboard electrical generators; all electrical power is provided instead by two banks of lithium ion batteries. While the Dolgarae-class boats require frequent snorkelling, the KSS 500A is designed to require minimal snorkelling during a typical three-week patrol.
The streamlined sail houses up to four masts for electro-optic, radar, satellite communications and electronic security measures systems, and there is a fifth - modular payload - mast for launching small unmanned aerial vehicles.
The pressure hull has four compartments: combat information centre, machinery room, special forces area and accommodation/messing. Weapons and sonars are installed in the forward section, while the integrated electric motor with coaxial flexible payload module (FPM) occupies the aft section.
Control surfaces include two bow-mounted dive planes and an X-shaped stern. A podded motor, stator and rotor propel the submarine at a cruise speed of 5-7 kt, although a sprint speed of 20 kt is possible. However, the endurance of 21 days and range of 2,000 n miles at low speeds are severely curtailed at higher speeds.
Although the boat can be operated by a crew of five, the design complement is 10 persons using a two-watch system. Up to 14 special forces personnel can also be embarked. The FPM at the stern allows the deployment of divers, swimmer delivery vehicles and unmanned underwater vehicles.
Armament comprises tubes for two heavyweight torpedoes and four lightweight torpedoes, located close to a payload interface module containing two box launchers: one for vertical-launch missiles, the other for mines. The KSS 500A is considerably larger than the Dolgorae-class boats. Built amid much secrecy, three Dolgoraes were commissioned in 1982-83 with pennant numbers 051-053. The legacy craft are about 25 m in length with a surfaced displacement of 250 tons. It is understood that five new mini-submarines are required by the RoKN, although induction timelines could not be ascertained.