China had begun to explore the wire guidance technology for torpedoes in the early 1960s but due to the political turmoil in China, the research stopped like many other Chinese research programs.
As a result, Yu-5 torpedo was developed, and it was decided to utilize the wire guidance technology.
The propulsion development of Yu-5 torpedo benefited greatly from the US Mark 46 torpedo recovered by the Chinese fishermen for the Otto fuel II research and then some technological supports for license production of Mk 46 Mod.
Other unconfirmed reports have claimed that during the development of Yu-5 torpedo, advanced American and Japanese commercial off-the-shelf technologies at the time were used,[1] and incorporating these advanced commercial technologies was part of the reason of the prolonged development, which lasted almost two decades.
The Yu-5 torpedo was finally accepted into the service in 1989 and the series production begun the next year in 1990.
Most components are shared commonly by ET34 and ET36, with the latter has a bigger warhead at the cost of reduced range, and like ET34, ET36 has selectable speed/range.