Yu-2 torpedo

Yu-2 (鱼-2, "Fish-2") torpedo was a Chinese development of the unguided straight-running Soviet ASuW RAT-52 torpedo with passive acoustic homing capability added. The historical background of Yu–2 is identical to that of Yu-1 torpedo and Yu-4 torpedo. Contrary to the higher number assigned, Yu-2 torpedo was the first Chinese domestically produced torpedo entering service, ahead of the Yu-1 torpedo.

In August 1958, the deputy chief-of-staff of PLA Zhang Aiping and the deputy commander-in-chief of PLAN Luo Shunchu led a military delegation to the Soviet Union and signed a deal with the Soviets to produce three types of torpedoes in China. In comparison with other military programs, each with dozens or even hundreds of Soviet advisers, the total number of Soviet advisers initially sent to China for these torpedo programs was just five. The Soviet Union quickly delivered the samples and technical information for the three types of torpedoes to China with the five advisers as promised. Two Soviet advisers were assigned to assist China to produce the RAT-52 rocket-powered torpedo at No. 123 Factory, while others were assigned to teach the Chinese about compressed-oxygen-powered torpedoes and SAET-50 acoustic homing torpedoes. In July 1960 the first two samples of Chinese-built rocket propelled torpedoes were completed. The type 920 electrical propulsion system and electronics of the passive acoustic homing torpedo had also been completed, while the basic technologies of compressed oxygen torpedoes were also mastered by the Chinese.

The subsequent Sino-Soviet split ended the promising future; from July 28 to September 1, 1960, the Soviet Union had quickly withdrawn all of its advisers from China. Compounding the problem were domestic political turmoils, such as the Great Leap Forward. The 7th Academy consequently ordered the 705th Research Institute to lead a team consisting of No. 724 Factory, Pinyang Machinery Factory (平阳机械厂) in Houma, Shanxi, and East Wind Instrumentation Factory (东风仪表厂) in Xi'an to indigenously manufacture Soviet-designed compressed-oxygen-powered torpedoes.

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