South Korea’s Navy To Start Operating New Stealth Submarine In May

South Korea's Navy will receive seventh Son Won II-class (Type 214) diesel-electric air-independent propulsion submarine built by Hyundai Heavy Industries, on Friday that is capable of operating underwater for more than 10 days.

The Hong Beom-do, is the world's top-level diesel sub that can handle more than 300 underwater targets at the same time and operate underwater for over 10 days without surfacing, Yonhap reports citing the Defense Acquisition Program Administration (DAPA).

The 1,800-ton sub, which is 65 meters long and 6.3 meters wide, will be delivered to the Republic of Korea Navy’s (ROKN) in a ceremony at the shipyard in Ulsan on Friday. The Navy will put it in combat operations in May after training a crew.

"On the basis of superb underwater operation capabilities, it will add to our Navy's underwater firepower, which is inferior to North Korea in number," Choi Hee-kyung, head of the agency's submarine program team, was quoted as saying.

Launched in April 2016, Hong Beom-do was expected to be delivered to the ROKN after extensive operational trials in July 2017. 

The Son Won II-class vessels are part of the second phase of the ROKN’s so-called Korean Attack Submarine program. It is a sharp improvement in major capabilities, including underwater operations, stealthiness, sonar ability and armament, compared with the 1,200-ton Chang Bo Go-class one.

With its air-independent propulsion system, built around Siemens polymer electrolytic membrane fuel cells, the submarine can stay submerged for up to two weeks and can dive up to 400 meters (1312 feet) deep. With its two MTU Friedrichshafen diesel engines, the Hong Beom-do is capable of reaching a top surface speed of 12 knots (and up to 20 knots when submerged with its electric motor), the builders had said during the launch in 2016.