VESSEL REVIEW | ROKS Ganghwado – Republic of Korea Navy places new submarine rescue ship into service

The Republic of Korea Navy recently welcomed a new auxiliary rescue vessel into service.

The vessel has been named ROKS Ganghwado (강화도함) after an island in the Yellow Sea off the coast of Incheon. Its primary function is to rescue crewmembers from distressed submarines.

The newbuild measures 120 metres (390 feet) long and 19 metres (62 feet) wide and has a lightship displacement of 5,600 tonnes, making it significantly larger and heavier than its predecessor, the 1996-built ROKS Cheonghaejin, which has a displacement of 3,200 tonnes. Construction of the new rescue ship took place at local shipyard Hanwha Ocean.

As the number of South Korea’s submarines grew in recent years, so did the demand for a suitable ship that could perform faster and more efficient rescues of distressed crews of submarines, especially while these are submerged. Design work on the replacement for Cheonghaejin commenced in 2015, and the shipbuilding contract was awarded to Hanwha Ocean (then still known as Daewoo Shipbuilding and Marine Engineering).

Innovative rescue arrangement for greater safety in rough seas

The new rescue ship can also accommodate approximately 130 crewmembers and is fitted with a deep diving system supplied by DRASS. The latter system is notable for having a different arrangement than on Cheonghaejin, which had its dedicated A-frame for deploying deep-submergence rescue vehicles (DSRVs) placed at the stern.

Although this arrangement enabled the submersibles to be lowered quickly, the A-frame was challenging to operate in rough seas with wave heights of more than two metres (6.6 feet).

For Ganghwado, the DSRV will be deployed not via the stern but amidships through a centrally-located well. This will enable the launch and recovery of DSRVs up to four metres (13 feet) long without compromising the larger rescue ship’s wave resistance, thus allowing rescue missions to be undertaken within a greater operational safety window.

Highly versatile platform with enhanced electronics and robotic systems

The ship’s propulsion system delivers a maximum speed of 20 knots. To aid in rescues, electronics including a multibeam echosounder and unmanned vehicles such as remotely operated vehicles (ROVs) can be integrated.

A flight deck is available for use by a UH-60 Blackhawk or MH-60R Seahawk helicopter while two rigid inflatable boats (RIBs) can also be carried.

Construction of Ganghwado was undertaken in fulfilment of a KRW469.9 billion (US$) contract awarded by the South Korean Defence Acquisition Program Administration (DAPA).