In August, 1958, the deputy chief-of-staff of PLA Zhang Aiping and the deputy commander-in-chief of PLAN Luo Shunchu (罗舜初) led a military delegation to visit former-Soviet Union signed a deal with Soviets to produce three types of Soviet torpedoes in China. In comparison with other military programs each with dozens or even hundreds of Soviet advisors, however, the former-Soviet Union did not put too much emphasis on torpedo capability: the total number of Soviet advisors initially sent to China for all of its torpedo programs was only five. The Soviet Union quickly delivered the samples and technical information of the three types of torpedoes to China with the five advisors to China as promised. Two Soviet advisors were assigned to assist China to produce the RAT-52 rocket-powered torpedo at No. 123 Factory, while others were assigned to teach China about compressed oxygen powered torpedo and SAET-50 acoustic homing torpedoes. In July 1960, the first two samples of Chinese-built rocket propelled torpedoes were completed. Type 920 electrical propulsion system and electronics of the electrically powered passive acoustic homing torpedo had also been completed, while the basic technologies of compressed oxygen torpedoes were also mastered by China.
