The Soviet Union quickly delivered the samples and technical information for the three types of torpedoes to China with the five advisers as promised.
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Sino-Soviet split ended the promising future; from July 28 to September 1, 1960, the Soviet Union had quickly withdrawn all of its advisers from China.
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.
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.
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.
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.