The Japan Maritime Self-Defense Force (JMSDF) commissioned its fourth Awaji-class mine countermeasures vessel (MCMV) in a ceremony held on March 12 in Yokohama City of Kanagawa Prefecture, south of Tokyo.
Named Nomi (with pennant number MSO 307), the 67 m-long boat was inducted into the service’s Minesweeper Division 3 at the Kure naval base in Hiroshima Prefecture shortly after being handed over by shipbuilder Japan Marine United (JMU) Corporation, which also built the other three ships of the class.
JS Nomi was laid down in May 2021 and launched in October 2023.
The ship’s name comes from the Higashi-Nomi and Nishi-Nomi Islands located in Hiroshima Bay. This is the second Japanese vessel to bear this name, following the former Imperial Japanese Navy’s coastal defense ship “Nomi.” The JMSDF‘s instructions state that minesweepers are to be named after islands or straits.
Fourth Awaji-class mine countermeasures vessel Nomi at the commissioning ceremony (Credit: Kosuke Takahashi)
A JMSDF spokesperson told Naval News that the vessel was constructed for about 18 billion yen ($121.6 million) under a contract awarded in 2021.
JMU has built all four Awaji-class MCMVs. The third ship, JS Etajima, was commissioned in March 2021.
In addition, the Ministry of Defense in Tokyo has allocated 13.4 billion yen ($90.5 million) for fiscal year 2022 to build the fifth vessel of the class, and 26.3 billion yen ($177.7 million) for fiscal year 2024 to build the sixth.
According to the JMSDF, the Awaji-class has a crew complement of around 50, a standard displacement of 690 tons, a beam of 11 m, and a draught of 5.2 m. Each of the vessels in service is powered by two diesel engines of 2,200 hp each and has a stated top speed of 14 kt.
The hull of these platforms has been constructed from a composite fiber-reinforced plastic material to reduce weight as well as the magnetic signature of the platforms during minesweeping operations. The material is also highly corrosion-resistant, according to the JMSDF.
A JMSDF spokesperson told Naval News that the Awaji-class vessels are expected to be in service for about 30 years while wooden-hulled minesweepers have a service life of about 20 years.
Fourth Awaji-class mine countermeasures vessel Nomi at the commissioning ceremony (Credit: Kosuke Takahashi)
JS Nomi is equipped with light detection and ranging (LIDAR) surveillance systems, which can locate objects under water at long range both during the day and at night.
The ship is equipped with the Mitsui E&S Holdings’ expendable mine disposal system (EMDS) for mine identification as well as with the Hitachi-made variable depth sonar (VDS) system, which is designed to detect, locate, and classify mines. It is also equipped with the Remus 600 autonomous underwater vehicle (AUV), known as OZZ-4 and made by the Woods Hole Oceanographic Institution, to locate and clear deep mines.
JS Noumi is also equipped with a remote control weapon station, armed with a JM61R-MS 20mm calibre cannon, mainly in order to deal with surfaced mines, the spokesperson said.
The Awaji-class has been built to replace the JMSDF’s three wooden-hulled Yaeyama-class minesweepers, the first of which entered service in 1993. All three of these ships were decommissioned by 2017.
Japan’s minesweeping capabilities are a specialty of the country. Minesweeping units have been active since before the establishment of the MSDF in 1954. They helped clear sea routes to clear mines laid by both the Japanese and US forces during the Second World War, and supported the postwar reconstruction of Japan as a maritime nation.
When the Korean War broke out in June 1950, the Japan Coast Guard’s Special Minesweeping Unit, established in 1948, was dispatched at the request of the U.S. to clear mines around the Korean Peninsula. In October 1950, a minesweeper struck a mine off the coast of Wonsan, North Korea, and sank, killing one crew member.
After the Gulf War that started in 1991, JMSDF minesweepers were also dispatched to remove mines in the Persian Gulf.