The “Taigei” class submarine is the latest diesel-electric attack submarine of the Japanese Navy. The first one was launched in 2020, and two have already been commissioned, with the third expected to be commissioned in 2024. It is not only Japan’s most modern submarine at present but will also become Japan’s most crucial underwater force in the future.
Eight “Taigei” class submarines are planned to be built. The most significant feature of this submarine is its distinct “cigar” shape, which simplifies processing difficulty while increasing the internal space of the submarine without significantly increasing the displacement. The “Taigei” class has an underwater displacement of 4,300 tons and is equipped with pump-jet propulsion usually used by nuclear submarines.
The “Taigei” class uses a power system that combines diesel engines with new large-capacity lithium-ion batteries, further reducing noise. The power comes from two 12V25/31S diesel engines produced by Kawasaki Heavy Industries, with over 25% more power generation than the “Soryu” class. The new lithium batteries have more than three times the density of traditional lithium batteries.
The “Taigei” class is equipped with the ZQQ-8 sonar system and an upgraded version of the ZYQ-51C combat system, improving the sensitivity of the sonar detection system and target processing speed. It also uses an “X-shaped” rudder to enhance underwater maneuverability. Made with NS-120 special steel, its maximum diving depth may exceed 500 meters.
The Type 039C submarine is China’s latest generation of conventional submarines, featuring an “elongated teardrop” hull design and a comprehensive strategy to reduce noise. It is equipped with a domestic AIP power system and an upgraded combat system used by the Type 039G submarines. According to foreign institutions’ estimates, the Type 039C submarine has an underwater displacement of over 3,600 tons, less than the “Taigei” class.
The US Navy news website reported that the Type 039C submarine has made significant breakthroughs in stealth and silencing technology, adopting a unique shroud design that is part of sonar stealth technology. The slanted sides are a form of stealth defense, reducing the submarine’s signal strength against enemy active sonar. Although other countries are also developing this technology, China was the first to apply it to submarines.
The new shroud on the Type 039C conventional submarine can also effectively reduce radar echoes, decreasing the likelihood of detection in semi-submerged states, significantly enhancing its survivability. The shroud can also significantly reduce underwater resistance and wake, enhancing underwater maneuverability. The Type 039C submarine is also equipped with a towed sonar system, significantly improving underwater detection capabilities.
In terms of weaponry, the Type 039C conventional submarine is equipped with the YJ-82 submarine-launched anti-ship missile, YJ-18B anti-ship missile, and new electric torpedoes, among which the YJ-18B anti-ship missile’s performance is significantly ahead of the missiles carried by US and Japanese submarines.
The YJ-18 is China’s current primary anti-ship missile, using a mode of subsonic sea-skimming flight and terminal supersonic flight, with a maximum range of 500-600 kilometers.
The main anti-ship missiles of the Japanese Navy are still primarily subsonic anti-ship missiles, which are relatively slow and have shorter ranges. For example, the Japanese Type 17 subsonic anti-ship missile has a range of only about 250 kilometers. It has relatively limited penetration capabilities against the current popular area air defense missiles, point defense missiles, and the “Phalanx” automated rotary cannon system.
Meanwhile, media reports suggest that China has recently developed multiple new-generation anti-submarine technologies and supersonic long-range anti-submarine missiles with revolutionary innovations, potentially equipping the Type 039C submarine in the future.
According to foreign media reports, Chinese scientists have developed a new detection device, the “ultra-sensitive magnetic detector,” which can effectively discover and track submarine positions and movements. Its sensitivity is thousands of times higher than traditional magnetometers, enabling it to detect smaller signals at greater distances, greatly improving detection efficiency and accuracy.
China has also successfully tested the world’s first submarine detection device using terahertz equipment. This technology can detect and identify small amplitude targets in the ocean, finding previously undetectable targets. This will not only greatly enhance China’s anti-submarine capabilities but also have a profound impact on global submarine detection and anti-submarine strategies.
Furthermore, China has developed a cross-medium supersonic long-range anti-submarine missile with a range of 200 kilometers. Currently, the main anti-submarine missiles of Japan and the United States typically have a range of only tens of kilometers and are subsonic. Additionally, the Yu-10 torpedo carried by the Type 039C submarine has overall performance comparable to the US Navy’s MK-48MOD7 heavyweight torpedo and the Japanese Type 18 torpedo.
Therefore, compared to the “Taigei” class submarine, China’s Type 039C submarine has overwhelming advantages in anti-submarine technology and weapon systems.
The US Navy news website also claims that the Type 039C submarine is one of the most advanced conventional submarines in the world, and China is building these conventional submarines at an astounding speed, unmatched by any other country, with the potential to build up to 40 submarines.
With its advanced power system and materials, larger displacement, the “Taigei” class submarine has certain advantages in maneuverability, maximum diving depth, and weapon payload. In contrast, China’s Type 039C submarine has obvious advantages in weapon systems and anti-submarine technology. Both submarines may have distinct advantages in stealth and silencing performance, with the Type 039C possibly having superior stealth capabilities.