Yu-2 Torpedo - Development

Development

China first imported the Soviet RAT-52 (RAT: Reaktivnaia Aviacionnaia Torpeda in Russian, meaning rocket airborne torpedo) rocket propelled ASW torpedo in 1954 and accumulated considerable experience in maintaining and handling the torpedo. With Soviet assistance in July, 1960, the first two examples of Chinese-built rocket propelled torpedoes were completed. Despite the Soviet withdrawal of technical assistance, a planned torpedo test was carried out in November, 1960 at Lushun. The result, however, was disappointing; not only that the test failed, one of the two torpedoes immediately sank upon entering water. Since China lacked any elaborate torpedo testing ranges the cause could not be determined. The development of Yu-2 torpedo was put on hold.

In 1964 the development of the Yu-2 torpedo resumed in China in No. 374 Factory. From July to September, 1969, a total of 24 torpedoes were test fired with satisfactory results, with speeds reaching 70 knots and ranges in excess of 1 km in water. From March to April, 1970, another 39 torpedoes were test fired.

Like the Yu-1 torpedo the Chinese micro-electronics industry was not capable of producing the passive acoustic-homing guidance package called for in the original specification. However, also like the Yu-1 torpedo the unguided version was pressed into service as the Yu-2. The acoustic homing version would come years later.

Two Yu-2 torpedoes could be carried by a Ilyushin Il-28 or a Nanchang Q-5. In comparison to the Soviet RAT-52 torpedo it was based on, the Yu-2 torpedo had twice the range in water but its warhead was 40 kg lighter. The speed of the Yu-2 torpedo is 40 / 70kt as opposed to the 58 / 68kt of Soviet RAT-52 torpedo.

Soviet researches have shown that a total of 8 direct hits of the RAT-52 torpedo would be enough to sink a 50,000 ton aircraft carrier. However, due to advances in naval air defenses, it was increasingly difficult for aircraft to come within weapons range of a target. The Chinese solution was to reduce the altitude of the approaching aircraft and attempt to postpone detection long enough to reach weapons range. However, RAT-52 torpedoes could not be dropped at low altitude. The Chinese solved this problem by incorporating additional control surfaces and modifying the winglets at the tail of the torpedo. Despite being now able to be dropped at very low altitude, incorporating passive acoustic-homing guidance, and having longer range underwater, Yu-2 torpedoes were obviously not suitable for modern warfare. Chinese research suggested that 8 direct hits on a 50,000 ton aircraft carrier was still able to guarantee the sinking, but under the intense air defense and acoustic countermeasures, a minimum of 58 Yu-2 torpedoes would have to be dropped. This in turn would require that a minimum of 29 aircraft successfully penetrate the fleet air defense. By 1984 all airdropped version of Yu-2 torpedoes were withdrawn from service.