North Korean Submarine Fleet

Note: Some submarines are assigned to reconnaissance and infiltration, for details of this mission and equipment see separate section.

22 x Type 031 (‘Romeo’) diesel-electric attack subs
4 x ‘Whiskey’ class attack/training subs (probably inactive)
20+ x ‘Yugo’ type midget subs
1 x ‘41m SSK’ diesel electric attack sub (probably inactive)
20 + x ‘Sang-O’ type midget subs
10+ x ‘P-4’ type midget subs
??+ x Other midget submarines and wet submarines

Type 031 (‘Romeo’) attack sub

Dimensions: L 76m, W 6.7m, Displacement 1,700t submerged
Armament : 8 x 533mm (21’’) torpedo tubes (6 forward, 2 aft) with up to 14 SEAT-60 heavyweight torpedoes or 28 mines

North Korea received some of these boats from China and subsequently locally produced some. Although they are relatively capable they are somewhat dated and ill suited to open ocean operations. There is no evidence to suggest upgrades.

’Yugo’ type midget sub

Dimensions: L 20m, W 2m, Displacement 90t (submerged)
Speed : 10kts surfaced, 4 kts submerged
Armament: 2 x533-mm externally-mounted torpedoes in drop gear in some variants, possibly torpedo tubes in some and none in infiltration variants.

The Yugo class is so named because it was built to plans supplied by Yugoslavia in 1965. North Korea had started an indigenous midget-submarine programme prior to that but had been somewhat unsuccessful, with a crude submarine being captured by the South in 1965 after its crew abandoned it when it was beached on a mudflat during a receding tide on the Han River:

Dimensions: L 5.7m, W 1.1m, Displacement: 3t (submerged)
Speed : 7kts (surfaces), 3kts (submerged).

Although the indigenous midget submarine appears to have been functional, it was very small and extremely limited for infiltration purposes which appears to be the primary peace-time operation for North Korean Navy.

The Yugo boats however are much larger and have room for 4-6 infiltrators and can carry torpedoes or mines for the attack role. They are relatively short ranged though so for infiltration (or attack in wartime) operations in the far south, off Japan or further away, they require transportation and launch from a mother ship.

The ships were built at Yukdaeso-ri shipyard on the west coast from the late 1960s through to the early 1980s at which time they were superceded by the generally more capable Sang-O type. Contrary to some sources, the North Korean Yugo submarine was not very similar to Yugoslavian operated midget submarines such as the impressive Velebit type.

In the early 1980s North Korea developed a much larger coastal submarine known, rather imaginatively, as the “41m boat”. No prizes for guessing the length of this submarine. It is not clear exactly what the boat looked like except that its sail is not unlike the Yugo’s in profile and that it was not a “teardrop” hull. The type does not appear to have been successful and only one is reported and it is unlikely to still be operable.

’Sang-O’ type midget sub

Dimensions: L 34m, W 3.8m, Displacement: 370t (submerged)
Power: 1 diesel, 1 electric motor, 1 shaft
Speed 7.2kts surfaced, 8.8kts submerged
Range: 1500nm
Max Depth: 150 meters
Crew: 15
Armament (attack sub): 4 x 533-mm torpedoes with no reloads (Inc Russian 53-65 ASW torpedoes)
Armament (recce/infiltration version): None. 5 infiltrators and 6 KWP Reconnaissance Bureau Cadre as passengers

Developed as a much improved follow-on to the Yugo type, the Sang-O is well known because one was captured by the South during a botched infiltration mission in September 1997. The Sang-O is much larger and longer ranged than its predecessor.

Some boats have the torpedo tubes replaced by a passenger space and diver swim-out door for infiltration and sabotage missions. The 1500nm range is useful enough to allow the boats to operate without a mother ship in most cases making them much less susceptible to detection.

Hypothetically these subs could be modified to carry anti-ship missiles or Shkval rocket-torpedoes but neither capabilities are reported. 

Chinese PM to visit SKorea, Japan in four-nation tour

Chinese Prime Minister Wen Jiabao will visit South Korea, Japan, Mongolia and Myanmar on a four-nation Asian trip starting later this month, the foreign ministry has confirmed.

Wen will attend a three-nation summit with South Korean President Lee Myung-Bak and Japanese Prime Minister Yukio Hatoyama on the island of Jeju in South Korea, ministry spokesman Ma Zhaoyu said in a statement late Friday.

The summit, on May 29 and 30, will likely focus on the North Korean nuclear issue, including the alleged torpedoing of a South Korean naval vessel by a North Korean submarine that killed 46 sailors.

Japan's foreign ministry announced the Japanese leg of Wen's visit earlier this week.

He is due to meet Hatoyama in Tokyo on May 31 and Emperor Akihito and Empress Michiko on June 1.

The four-nation trip will last from May 28 to June 3.

Relations between Asian giants Japan and China, the world's number two and three economies respectively, have warmed but are still often strained by their wartime history and ongoing disputes over territory and resources. (AFP)

Experts suggest possible attack by N.K. submarine

With an external explosion being cited as the most likely cause of the sinking of the Cheonan, allegations are growing that a torpedo, fired by a North Korean submarine, could have caused the disaster.

Experts say that given the shallowness of the waters near the western inter-Korean maritime border, a 325-ton shark-class submarine could have entered South Korean waters undetected.

Rep. Kim Hak-song of the ruling Grand National Party who chairs the National Assembly’s defense committee said on April 5 that he was briefed by the military that movements of two shark-class submarines at the North’s naval base in Bipagot -- some 80 kilometers north of Baengnyeong Island -- were detected before and after the incident occurred on March 26.

Kim also said the whereabouts of one of the submarines was not verified, fueling speculation that a North Korean submarine entered the South’s waters and fired a torpedo at the Cheonan, which was traveling 1.8 kilometers southwest of Baengnyeong Island.

If a shark-class submarine traveling at 13 kilometers per hour had come from Bipagot, it would have taken six to seven hours to reach the waters near Baengnyeong Island.

To avoid being detected by the South’s surveillance, the submarine might have operated only underwater. However, experts say that the submarine should come above the water periodically for air.

“It depends on how many people are aboard the vessel. The submarine should come above the water to emit carbon dioxide created by crewmembers inside,” a submarine expert told The Korea Herald on condition of anonymity.

Experts believe that if the North’s submarine had infiltrated the South’s waters, it might have moved from the waters far west of Baengnyeong Island rather than taking a route between the island and the North’s province of Hwanghae.

They believe that the North’s submarine could not take the route because of the tidal currents between the island and the province and the South’s military has been tightening its security along the route.

Speculation Focuses on N.Korean Semi-Submersibles

As more evidence surfaces about the sinking of the Navy corvette Cheonan on Friday, speculation is increasingly focusing on a possible attack from one of the North Korean semi-submersibles reportedly operated by crack teams and capable of carrying two torpedoes or mines.

A North Korean semi-submersible carrying two torpedoes (marked)

Semi-submersible vessels weigh less than 300 tons and are smaller than submarines. The waters where the Cheonan sank are only 20 m to 30 m deep and difficult for North Korea's mainstay 1,800 ton Romeo class submarines to negotiate. North Korea allegedly uses the semi-submersibles when transporting spies on infiltration missions into South Korea. These flat boats approach coastal waters remaining mostly submerged under water and disappear completely under water as they near the coastline, which makes it extremely difficult to detect them. Defense Minister Kim Tae-young told lawmakers on Monday the semi-submersibles can fire two torpedoes and did not rule out that such a vessel may have attacked the Cheonan.

Kim Hak-song, the head of the National Assembly's Defense Committee, stoked speculation by saying he had heard that North Korean semi-submersibles left their base around that time, but high-ranking military officers said the claim is unfounded. 

SSC Sang-O Class

While the North Korean submarine force reflects dated technology by Western standards, North Korean submarines during wartime would present significant challenges, particularly in coastal areas. North Korea has placed high priority on submarine construction programs which are ongoing despite its economic hardships. An example of this is the SANGO SSC, a simple submarine constructed in two variants, for use in the covert insertion of Special Operations Forces (SOF), mining or antisurface warfare. The submarine comes in two different variants, one with torpedoe tubes and the second without but with the capability to lay mines.

The Sang-O (Shark) class submarines are used for special forces infiltration into South Korea and have at times been captured by ROK forces. According to Janes Fighting Ships 2002-3 Sang-o class submarines began to be constructed in 1991 at Sinpo and were be constructing at 4-6 a year by 1996. Reports indicate that only three were built in 1997 and it is unclear what was produced in the following years.

Bitter enemies since the outbreak of war in 1950, the two Koreas remain divided by the most heavily guarded border in the world - one the North regularly attempts to penetrate. The 18 September 1996 grounding of a North Korean submarine filled with 25 heavily armed commandos - stunned the South as communist soldiers waded ashore 90 miles northeast of Seoul. Deadly skirmishes followed for two months as the commandos attempted to flee north, with most of the team being killed along with several South Korean soldiers and innocent civilians. The North Korean submarine got stranded on some underwater rocks, forcing the crew to get out and try to return to North Korea. This prompted a deadly manhunt that lasted over a month (25 of the 26 crew members were shot dead and the South Korean casualties, civil and military, tallied 17).

Once inside the submarine one really wonders how 26 people could have fit in such a cramped space – let alone live. Following this incident, North Korea officially apologized and assured that he would do all his best to prevent such a thing from happening again. Two years later another submarine, a much smaller Yugo class, was found entangled in South Korean fishing nets

Unification Park is composed of unification security pavilion. It was opened in September 26, 2001. To display the tanks and field artillery additionally in the outdoor exhibition area in the future, revitalization of local economy can be achieved in connection with the Jeongdongjin Sunrise Resort displaying the artillery of the armed forces fro the first time in the nation. In addition to the pavilion of North Korean submarine moved and displayed in the site in May 1998, the retired warship, Jeonbukham, was lent for free to Gangneung in order to be reused as an education arena of national security culture from the navy (Globalsecurity).

Specifications
Displacement:	tons submerged, surfaced
Length	116.5 ft
Beam	12.5 ft
Draft	12.1 ft
Propulsion	Diesel electric
Maximum Speed	7.6 kts surfaced 7.2 kts snorting 8.9 kts submerged
Mines	16?
Torpedoes	2-4 21 inch tubes (533mm) [in some] Russian Type 53-56 torpedoes
Crew	19 + 6 divers