Japan seeking an advantage in submarine warfare.

Tokyo acquires unmanned underwater vehicles and partners with Australia to counter China’s growing underwater threat.

Japan aims to strengthen its underwater warfare capabilities around the strategic Nansei Islands off China by acquiring new unmanned underwater vehicles (UUVs) and partnering with Australia to obtain such technologies.

Asian Military Review has reported that the Japan Maritime Self-Defense Force (JMSDF) plans to enhance its ocean observation capabilities with new UUVs and long-range underwater acoustic communication systems.

The report mentions that the JMSDF has signed contracts for the acquisition of Type I and Type II underwater gliders to conduct oceanographic studies on water temperature, salinity and currents.

It also states that the JMSDF has contracted local electronics company NEC to develop the Long Distance Underwater Acoustic Communication Module for UUV control, position awareness and underwater ship communication.

The JMSDF uses Mitsubishi Heavy Industries’ UUV OZZ-5, equipped with a dual-imaging sonar array, to detect buried objects at low frequencies and perform high-resolution scans of exposed objects on the seafloor.

In addition to the OZZ-5 UUV, the report states that the JMSDF also uses the Hydroid REMUS 600 autonomous underwater vehicle (AUV) for mine countermeasures (MCM) operations.

Meanwhile, Janes reported last month that Japan and Australia have signed a bilateral agreement to jointly develop robotic and autonomous systems (RAS) for underwater warfare. According to Janes, the agreement aims to improve underwater communication technologies and interoperability of both countries.

Australia’s Defense Science and Technology Group (DSTG) and Japan’s Acquisition, Technology and Logistics Agency (ATLA) will establish underwater acoustic communications evaluation indices using simulators and test and evaluation simulations.

The Janes report notes that the results of this project are expected to be used for future interoperability of unmanned underwater vehicles (UUVs) between Japan and Australia.

The first joint research project on underwater communication technologies is expected to be completed by the end of 2027, with research and development activities to be carried out in Japan and Australia at ATLA and DSTG facilities.

Japan could use its UUVs for mine warfare and anti-submarine operations around the Nansei Islands, which straddle the Miyako Strait, a critical maritime chokepoint for China in the event of an invasion of Taiwan and its arsenal. submarine-based nuclear

The Miyako Strait has seen repeated incursions by People’s Liberation Army (PLNA) warships attempting to exit the First Island Chain formed by Japan, Taiwan and the Philippines into the Pacific Ocean, ostensibly to conduct a flanking maneuver against Taiwan and separate the autonomous island from American reinforcements.

China’s nuclear-powered ballistic missile submarines (SSBNs) armed with the older JL-2 submarine-launched ballistic missile (SLBM) may have to reach open Pacific waters to put Guam, Hawaii and the US mainland within range of an attack, with the Miyako Strait together with the Bashi Channel being possible underwater routes.

In a paper presented during the 2019 IEEE International Conference on Unmanned Systems, Zhiyun Zhao and other authors detail how UUVs can be used in anti-submarine operations.

Zhao and others describe the unique operational characteristics of UUVs, including a low level of acoustic, magnetic, electrical, and other signatures. They point out that UUVs have a greater concealment capacity than manned submarines, which allows them to replace the latter in carrying out operations in areas that are difficult to access or too dangerous for manned ships.

They note that UUVs combine high endurance and autonomy, allowing them to independently patrol predetermined maritime areas and guide or coordinate with manned platforms to carry out offensive anti-submarine operations.

They also claim that UUVs can fill gaps in anti-submarine warfare capabilities, such as the poor performance of sensors in shallow waters and the limited detection range of fixed underwater sonar systems.

However, Zhao and other authors point out the limitations of UUVs in anti-submarine warfare, stating that the vast areas involved and the duration of such operations mean that UUVs must often be used in groups. They point out that the relatively short range of the sensors and the low speed of individual UUVs require coordinated and centralized employment.

They also point out the complexity of the command and control (C2) systems required to employ UUVs effectively, stating that multiple means of communication with UUVs, such as satellite and data links, are needed to attack sensitive targets such as nuclear submarines.

Regarding anti-submarine operations with UUVs, Zhao and others mention that UUVs can be deployed near enemy naval bases or ports to monitor their submarines, bottleneck ships in port, block critical maritime choke points, lay ambushes, or search for and destroy enemy submarines. and serve as a decoy for submarine attacks.

UUVs could soon become a focal point of practical cooperation between Japan and the AUKUS trilateral security partnership, made up of Australia, the United Kingdom and the United States.

Seth Robson noted in an article published in Stars and Stripes in March 2023 that Japan still wants to join AUKUS, as the partnership goes beyond controversial nuclear submarines to encompass emerging technologies such as quantum computing, artificial intelligence, the autonomy of machines, hypersonics, counter-hypersonics, electronic warfare, underwater warfare and cyberwarfare.

Robson also points out caveats to Japan’s plans to participate in AUKUS. On the one hand, he claims that AUKUS is already very busy with its efforts to provide nuclear submarines to Australia and may not have much left to spare for further commitments.

Likewise, he states that information security with Japan may also be a concern, mentioning that Australia, Canada, New Zealand, the United Kingdom and the United States have a high level of mutual trust thanks to their membership in the information exchange alliance. Five Eyes intelligence, with its well-established security clearance systems. On the contrary, he asserts that Japan may have work to do in this regard.

Gabriel Honrada