‘Highly unusual’ North Korean submarine activity spotted by US military
The US military has detected “highly unusual and unprecedented levels” of North Korean submarine activity in the wake of that country’s second intercontinental ballistic missile launch late last week, CNN said on Monday.
Citing a defence official, the television news channel reported that North Korea on Sunday carried out a trial of the missile component that is critical to developing submarine launch capabilities.
The “ejection test”, carried out on Sunday on land at the Sinpo Naval Shipyard, was the third this month and fourth this year. It came after North Korea test-launched its second ICBM late Friday night.
According to the report, an ejection test examines a missile’s “cold-launch system”, which uses high pressure steam to propel a missile out of the launch canister into the air before its engines ignite. That helps prevent flames and heat from the engine from damaging either the submarine, submersible barge or any nearby equipment used to launch the missile.
The ejection test took place amid the backdrop of increased activity by North Korea’s submarine fleet, believed to comprise about 70 subs though most are quite old and likely cannot fire missiles.
Earlier this month, for example, North Korea sent a diesel-powered Romeo-class sub on an unprecedented patrol in waters off the coast of Japan, CNN said, citing US defence officials.
The sub patrolled farther that it has ever gone, sailing some 100km out to sea in international waters and causing US and South Korean forces to slightly raise their alert level.
Besides around 20 former model Romeo-class subs, North Korea’s fleet is believed to include some 38 Sang-O primary subs and one newer Gorae sub, which is being outfitted with a possible missile launch demonstration tube, CNN reported.
When taken together, it said, these developments are concerning because North Korea says it is trying to develop a missile capable of delivering a nuclear warhead to the United States.
But the current US intelligence assessment is that the missile programme aboard submarines remains in the very early stages, it said.
Last summer, North Korea conducted what experts believed was its first successful submarine missile test, firing a missile called the KN-11 or Pukguksong-1.
In 2010, a South Korean naval vessel sank in the Yellow Sea, allegedly after being hit by a torpedo fired by a North Korean sub, resulting in the deaths of 46 seamen.
Since then, South Korea has been beefing up its underwater warfare capability against North Korea. On July 10, its navy took delivery of a new 1,800-tonne, diesel-powered submarine, the six of its Jang Bogo-II Class fleet launched in December 2008.
The advanced sub is said to be able to operate for 10 days or longer without surfacing above the water and to handle more than 300 underwater targets at the same time.