Bbarŭn-class submarine

File:ISS Ssori.png From top to bottom: Bbarŭn-I, Bbarŭn-II, and Bbarŭn-III variants
Class overview
Name:	Bbarŭn
Operators:	Menghe
Cost:	$400 million (Bbarŭn-1)
General characteristics
Type:	Diesel-electric attack submarine
Displacement:	Bbarŭn-I: 1,990 tonnes surfaced, 2,910 tonnes submerged Bbarŭn-II: 2,270 tonnes surfaced, 3,250 tonnes submerged Bbarŭn-III: 2,750 tonnes surfaced, 3,960 tonnes submerged
Length:	Bbarŭn-I: 67.3 meters Bbarŭn-II: 73.6 meters Bbarŭn-III: 83.5 meters
Beam:	9.9 meters
Draught:	7.9 meters (surfaced)
Propulsion:	Bbarŭn-I: Diesel-electric propulsion Bbarŭn-II and III: Diesel-electric with AIP module
Speed:	11 knots surfaced 22 knots submerged on batteries 6 knots submerged on AIP
Range:	3250 nm (6000 km) with snorkel at 7kts 400nm (740km) at 54kts
Endurance:	45 days total Bbarŭn-II and III: 12 days submerged on AIP
Complement:	Bbarŭn-I: 23 Bbarŭn-II: 31 Bbarŭn-III: 37
Sensors and processing systems:	1x multifunction search radar mast 1x VLF receiver antenna
Electronic warfare & decoys:	1x ECM mast
Armament:	Torpedoes: 8 533mm torpedo tubes (bow) (16 torpedoes carried) Missiles: 1 × 4 MANPADS SAM launcher 12x VLS cell for YDH-90, YDH-29, or SY-50 Mines: 52x externally mounted naval mine Additional mines in place of torpedoes

The Bbarŭn-class submarines (Menghean: 빠른급 공격 잠수함, Bbarŭn-gŭb Gonggyŏk Jamsuham) is a family of Diesel-Electric attack submarines in service with the Menghean Navy. Compared to its predecessor, the Danhohan class, it is faster and incorporates considerably higher levels of quieting technology. In addition to the original Bbarŭn-I production variant, two additional sub-classes exist. The Bbarŭn-II is fitted with an air-independent propulsion module containing two water-driven Stirling engines, allowing the submarine to remain submerged for up to ten days while traveling at a speed of six knots. In addition to this module and sound reduction, the Bbarŭn-III is fitted with twelve vertical launch tubes for cruise or anti-ship missiles, which can be fired while the vessel is submerged.

Bbarŭn-I

As its project name suggests, the Bbarŭn-I was designed in 1983, during the twilight years of the DPR Menghe regime. It was intended first and foremost as a coastal counteroffensive attack-submarine, which could engage hostile fleets in relatively shallow waters where detection is difficult. At the time, the leaders of the DPR regime were concerned about the possibility of an Oyashimese attack, and saw such a submarine as vital to naval combat in the island-strung waters between the two countries. A production run of at least 30 hulls was planned, but due to economic problems and budget cuts only five vessels were completed before the Decembrist Revolution that brought the Menghean government to power. Production was subsequently resumed, albeit at a lower pace, until the 2004 Naval Reforms led to the perception of a need for better coastal submarines.

The Bbarŭn-I's main armament consists of eight torpedo tubes in the bow, arranged in two rows of four. This heavy armament was intended to allow the submarine to inflict more damage on an enemy fleet in a short period of time, either before being destroyed or before being forced to flee. In order to make room for the tubes themselves, the total ammunition load was reduced; only 16 torpedoes can be carried, enough for one full salvo and a single reload. Certain anti-ship missiles, mines, and standoff anti-submarine missiles can be carried in place of torpedoes, though this was seldom done in practice due to the limited capacity of the magazine. In order to partially compensate for this drawback, the Bbarŭn-class was fitted with external rails along its back, which can be used to carry up to 52 mines and lay them while submerged. While external mines are being carried, however, the submarine generates additional turbulence noise and its maximum speed is reduced.

Other design features included a high level of quieting for its time, making the Bbarŭn-I hard to locate in coastal waters. Coastal mobility was further improved through the use of a shorter lower rudder to reduce draft. In order to increase survivability, the interior of the submarine is divided by six watertight bulkheads whose doors can be sealed in order to contain fire or flooding. When surfaced, the Bbarŭn-class can deploy an integrated electronic warfare mast with a radar-warning receiver, an active radar jamming antenna, and an air-and-surface-search radar array. Also mounted on the sail is a remote-controlled surface-to-air missile launcher containing four MANPADS missiles in sealed tubes; this weapon, intended to engage ASW aircraft and helicopters, cannot be operated while the vessel is submerged.

Bbarŭn-II

The first major upgrade to the Bbarŭn-class came in 2003, when the Menghean Navy began considering an operational exploration of air-independent propulsion. One Bbarŭn-I, Sinjunghan, was taken into drydock and converted into an AIP testbed with an additional Stirling engine module. Coastal testing with hydrographic survey ships soon found that the level of quieting was still insufficient, while engine performance and endurance were well below the projected thresholds. Three years later, however, Menghean engineers took advantage of thawing relations with the Oyashimese Federation by arranging for the purchase of several Oyashimese Stirling engines to serve as design examples. These engines, when put to use in a different testbed conversion, were found to perform far better than the Menghean models, and plans were immediately developed to produce them under license and install them in a dedicated subclass.

This addition required a "stretch" modification, lengthening the submarine by approximately 6.3 meters aft of the sail to make room for the new auxiliary powerplant. This necessitated eight additional crew members, increasing the complement to 29. Additional quieting measures in the form of modified machinery mounts were also installed in other parts of the submarine. In this configuration, produced since 2007, the Bbarŭn-II is able to travel submerged at up to 6 knots for a period of up to 10 days, all while making very little noise. This increased independence allows it a greater chance of slipping past the escorts of an enemy fleet. In addition to new-build vessels, roughly one-third of already existing Bbarŭn-I-class submarines have been taken into drydock and rebuilt to the Bbarŭn-II standard.

Bbarŭn-III

The Bbarŭn-III, like the Bbarŭn-II before it, is based on a "stretch" of the Bbarŭn-family hull, this time increasing length by an additional 9.9 meters. In front of the Stirling AIP module, the submarine is fitted with a launch system for twelve missiles, which are stored vertically in the center of the hull. The tubes are compatible with the MJ-29, a sub-sonic anti-ship missile with a range of 350 kilometers; the MJ-90, a supersonic anti-ship missile with a supersonic terminal stage and a range of 250 kilometers; and the FJ-50 land-attack cruise missile with a mid-altitide range of 2,000 kilometers. The former two missiles are intended to augment the submarine's existing torpedo armament, allowing it to swarm a warship's defenses unexpectedly. As the noise produced by a series missile launch would reveal the submarine on passive sonar, such an attack may be executed at range before the submarine has slipped past the escorts, or alternatively may be used in combination with a torpedo salvo when the target is relatively close. The inclusion of a land-attack cruise missile suggests that the Bbarŭn-III may be used as a concealed fire platform to provide strikes against strategically valuable targets along the coast or further inland, and indicates the new priorities created by "War Plan Blue" and the possibility of a conventional coastal war with the People's Republic of Innominada.