Yu-6 Torpedo

The Yu-6 is the 533mm wire-/acoustic-/wake-homing heavy torpedo designed by 705 Institute (also known as Xi’an Precision Machinery Institute), a R&D branch of the China Shipbuilding Industry Corporation (CSIC) in Xi’an, Shaanxi province. The Yu-6 is the most advanced and capable indigenous torpedo in service with the People’s Liberation Army Navy (PLAN), designed to engage both deep-diving submarines and surface ships. The torpedo entered the PLAN service in 2005, carried by the Type 039 (Song class) and Type 039A (Yuan class) conventional submarines, and possibly the newly launched Type 093 (Shang class) and Type 094 (Jin class) nuclear-powered submarines too.

In the mid-1980s, the PLAN decided to develop a new heavy torpedo for both anti-ship warfare (ASuW) and anti-submarine warfare (ASW) roles, by reverse-engineering a single Mk-48 torpedo recovered by Chinese fishermen in the late 1970s or early 1980s. The development project was later put on a halt after few prototypes were produced due to enormous technical difficulties and lack of funding. However, research on the Otto fuel II and wire guidance was continued by a small team.

As the PLAN realised that its current torpedoes were unable to meet its requirements for modern naval warfare, the Yu-6 project was officially revived in 1995, with Dong Chun-Peng appointed as the chief designer. The revised Yu-6 design has possibly incorporated some Russian technologies, particularly the unique wake-homing technology. A number of Chinese organisations were involved in the Yu-6 development, including Shanghai Jiaotong University that developed new alloy for the torpedo casing; Tianjin Rubber Research Institute that supplied the noise-reduction casing for the acoustic seeker; Harbin Electro Carbon Research Institute tasked to develop the graphite material used to make engine valves and other components; Yizheng Shuanghuan Piston Ring Co. Ltd. that developed the piston ring for the torpedo propulsion.

It was reported that the Yu-6 adopts a combined wire + active/passive acoustic + waking-homing guidance for different types of targets. It guidance system reportedly uses an Intel 80486-class microprocessor. The Yu-6 was also the first Chinese torpedo designed with the concepts of modular design and open architecture software programming in mind, so that new technologies and programmes could be readily incorporated whenever they become available.