The “New” North Korean Tactical Nuclear Missile Submarine

North Korea launched a submarine to be equipped with 10 tactical nuclear missiles. The dimensions of the missile launch tubes in the sail of the boat indicate that they will be equipped with four of the Pukguksong family of ballistic missiles and probably six smaller missiles. The vessel was launched on September 6th amid great fanfare with North Korean leader Kim Jung Un in attendance.

The submarine is not new. It is a Romeo type designed by the former Soviet Union in the late 1950s. The class was an enlarged Whiskey type based on the World War Two German Type XXI. The Soviets stoped the program in favor of nuclear powered boats, however the class continued to be built by Red China as the Type-033, and was used by several navies. Most have been retired, or reduced to training vessels, however, the North Koreans operate about 20, including this boat heavily modified boat. Seven were supplied by China between 1973 and 1975. The other were constructed by the North Koreans between 1976 and 1995.

Unmodified North Korean Romeo Submarine with Kim Jung Un Aboard

The modifications include a more streamlined hull with the old bow and torpedo tubes crudely cut off and replaced by semi-spherical cap. The sail was streamlined and the diving planes formerly mounted on the mounted on it. The sail is lengthened to provide room for the ten missiles to be mounted in vertical launch tubes. The stern appears to be photoshopped to erase the rudder or screws. Note the drawing of a Type-033 or Romeo below.

Drawing of a Stock Romeo or Type-033

Although the North Koreans are talking about the boat, named Hero Kim Gun-Ok, and numbered 841. The modifications are significant enough to make her look new. In 2019 North Korea revealed a ballistic missile submarine based on the Romeo, the Sinpo-C. It was less modified and housed 3 Pukguksong missiles in its sail. It retained the original bow and torpedo tubes.

Like the Sinpo-C, the Kim Gun-Ok, appears to mount its missiles aft of the battery compartment and control room and forward of the diesel engines. It is likely that the design will compromise its ability to remained submerged as the number of batteries will likely have been reduced as the missile tubes like those of the Sinpo-C, drop into the former aft battery compartment. It is unknown if the new boat is the Sinpo-C or another Romeo. The boat’s technology is 1950s era Soviet technology, and the hull and propulsion machinery are at the minimum thirty-years old, if not older. The Romeo’s, like most Soviet boats are loud by comparison and easily detectable by the modern nuclear American or diesel submarines of South Korea. It is unlikely, despite the modifications, that Kim Gun-Ok will be significantly quieter. Likewise, the modifications will probably make her slower underwater than other Romeo’s.

The sail is massive for a boat of its limited displacement and beam as before the modifications it displaced 1400 tons on the surface and retained the 22 foot beam of the Romeo type. This is an exceptionally small platform to load 10 missiles in a sail. In the 1960s the Soviet Union developed the Golf Class which mounted three missiles in its sail. That boat displaced over 3000 tons and had a beam of over 27 feet. The North Koreans received 10 Golf Class boats in 1990 to scrap, but it is unknown if that occurred and some reports indicated that the North Koreans could be attempting to rehabilitate one to carry missiles, but those reports were shown to be in error when the Kim Gun-Ok proved to be a Romeo.

This could pose a danger on the surface. The sail appears to tower over the main deck by 15 to 18 feet, and since the boat only has a drought of 17 1/2 feet the boat could be very unstable in any sea sea state when surfaced. One has to speculate about how she will handle underwater, especially with a crew inexperienced in handling such a vessel. The South Korean Joint Chiefs of stated that because of the modifications to the boat to accommodate the missiles that it “could not be operated normally.”

Admittedly, the fact that the boat is designed to carry nuclear missiles does complicate U.S. - South Korean strategy. However, one submarine is hardly a year round deterrent. The North Koreans will need several more boats, more advanced than the Kim Gun-Ok to have a credible nuclear submarine force. Kim Jung Un said that “The nuclear attack submarine, for decades a symbol of aggression against our republic, has now become a symbol of our revolutionary power to strike fear into the hearts of our despicable enemies.”

The North Korean dictator’s bellicose words are normal for him, however, with every increase in nuclear missile technology, and the diversity of launch platforms he and North Korea become more dangerous. He has promised to develop nuclear powered submarines, although such would be a quantum leap that most modern Western navies with the capacity to do so do not attempt.

Nuclear powered submarines represent a significant financial and technological burden, and most countries that do not need to operate long distances from their home ports can meet their need for submarines with incredibly quiet and advanced designs such as the German U-212A, U-212CD, and U-212NFS types. These boats are used by Germany, numerous NATO nations, or as the Israelis have done with the German designed Dolfin class available. Other options include the Swedish Gotland class, and the very modern Japanese Soryu class. The Red Chinese have developed some advanced diesel boats as well. The Russians still operate and export their Kilo Class. One new navy to join the nuclear attack submarine club will be Australia, which will be obtaining U.S. Navy Virginia Class boats as a deterrent to China.

South Korean Dosan Ahn Changho submarine, surfaced above, and below

The South Korean Navy operates 18 German type U-209 and U-214 subs built under license in South Korea, and has recently introduced indigenous Dosan Ahn Changho class displacing nearly 4000 tons and having the capacity to launch ballistic missiles, cruise missiles, anti-ship missiles, and torpedoes.

Since Kim Jung Un is reportedly going to visit Vladimir Putin in Moscow this month it is not beyond the imagination to assume that he might ask for assistance in building a nuclear boat or acquiring modern diesel-electric boats, but it is uncertain that Putin, deeply embroiled in Ukraine and facing shortages in supplying and sustaining his navy would be willing to help a poor country unable to pay cash for that technology.

Regardless, the North Korean moves to build submarines capable of carrying nuclear missiles need to be carefully monitored.

I will be plowing ahead in doctoral work this weekend so my next article will appear on Monday.