Chinese Type 039B submarine conducts maritime combat training.

According to information published by Chinamil on August 18, 2022, a diesel-electric submarine (that could be Type 039B) attached to a submarine flotilla with the navy under the PLA Northern Theater Command sailed in a sea area during a maritime training exercise.
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Possibly a Chinese Type 039B submarine (Picture source: Chinamil)

The Type 039B submarine is an AIP conventional submarine developed and built on the basis of the Type 039A submarine. The first submarine of this class was launched at the end of 2013. It has several major improvements and upgrades.

First, the boat has an elongated hull with a long teardrop shape design, which is more suitable for the oceanic combat environment. It is relatively long and has a correspondingly large length and width.

The main purpose of this design is to provide a larger internal space, which allows for easier installation of hull equipment and more load to improve the crew's working environment, but the disadvantage is that the sailing resistance has increased, which also has an impact on the submarine's maneuverability.

Secondly, the power system continues to be optimized and upgraded, based on the technology of the localized Stirling engine, and boldly improved to enhance the power and reliability of the engine. The AIP system is a Stirling engine, which has further improved the submarine's underwater combat and silent performance compared to the 039A system.

Third, the hydroacoustic system was upgraded. The hydroacoustic system is the "eyes and ears" of the submarine and has been one of the shortcomings of China's submarine technology.

In order to support the use of the new Fish-6 heavy torpedo, the Type 039B submarine is also equipped with a more complete hydroacoustic system, with a larger array of sonar installed on the bow of the boat.

Because of the long-range of the fish-6, the bow array sonar is required to provide fire control solution and target indication for the torpedoes within the maximum range, which requires a larger base array to improve the detection distance of the sonar. Working frequency, improve the detection distance.

As the backbone of the Chinese Navy's ocean-going operations, the Type 039B submarine may have to face the world's most advanced nuclear attack submarines and conventional submarines, so it must be further improved in terms of silence, first of all by optimizing the shape, including the command deck enclosure design optimization mentioned earlier, and also by equipping the hull with anechoic tiles.