Key point: China's torpedoes have gone through years of steady upgrades.
The current fleet of Chinese sub-launched torpedoes represents an interesting blend of Soviet, American and commercial off-the-shelf (COTS) technology. From the Yu-4, a domestic completion of an incomplete Soviet design, to the Yu-6, which uses an Intel microprocessor to power its guidance components, the torpedoes of the People’s Liberation Army Navy (PLAN) show significant traces of reverse engineering. But how capable are they? Do they really improve on the designs on which they are based, and effectively integrate COTS technology, or stand up to the designs from which they were reverse engineered?
The first torpedo fielded by the PLAN for sub-to-sub (ASW) combat was the Yu-3 (鱼-3). As part of the development program for its fleet of nuclear submarines, the PLAN needed an ASW torpedo. Design began in 1964, with sea trials beginning in 1972 and mass production in 1984. Almost all technology and design was indigenous. The torpedo itself is rather lackluster for one adopted in 1984, puttering along at thirty-five knots and using solely passive guidance. The only “advanced” feature was the torpedo’s ability to circle back and reacquire the target if it missed on the first pass. It was later modernized in 1991 to use active/passive guidance. Some sources also state that it was given wire guidance at this time. Overall, it was far inferior to its 1980s Western or Soviet counterparts.