Yu-6 torpedo

Yu-6 (鱼-6) torpedo is the Chinese equivalent of the Mark 48 torpedo. In addition to wire and active / passive homing guidance, wake homing guidance is also incorporated. Many domestic Chinese sources have claimed that Yu-6 torpedo is in the same class as the Mk 48 Mod. 4 torpedo, but official information of Yu-6 torpedo released by the Chinese government is limited and such claim thus cannot be confirmed by sources outside China.

Background

At least one Mark 48 torpedo was reportedly recovered by Chinese fishermen in the late 1970’s or early 1980’s, and China might have begun the reverse engineering in the 1980’s. However, due to the inexperience of the Chinese technological base at the time, as well as the concentration on economic development, most of the reverse engineering attempt was put on hold after research had been completed on Otto fuel II, wire guidance and some other subsystems, but some research continued on much smaller scale. The Yu-6 torpedo developmental program experienced a revival when the Chinese military realized that despite developing several torpedoes including the Yu-1, Yu-2, Yu-3, Yu-4, and Yu-5, the obsolete doctrine of having separate ASuW and ASW torpedoes proved to be unsuited for modern naval warfare and the Chinese navy needed a torpedo for both ASuW and ASW. As a result, the Yu-6 program was fully resumed in 1995 and 705th Institute was named as the primary contractor, Mr. Dong Chunpeng (董春鹏) as the general designer.

Development

One of the difficulties encountered was that the Yu-6 torpedo had greater operating depth than all previous Chinese torpedoes, and China could not build the new casing needed. A brand new alloy was required to cast the outer casing of the Yu-6 torpedo, and under the leadership of Professor. Ding Wenjiang (丁文江) of material science at Shanghai Jiao Tong University, the problem was solved when ZLJD-1S alloy was successfully developed and used to cast the casing for Yu-6 torpedo. Professor He Yuyao (贺昱曜) was in charge of developing power module for the newly developed computer of Yu-6 torpedo, and due to extremely high standard of the processing capability that demanded very advanced power source, this power module took three years to complete, (1999 – 2001).

Another huge obstacle faced was the casing for the acoustic seeker required new materials to build, but China had never had any experience in this field when the reverse engineering was first attempted. Despite most reverse engineering attempt was put on hold, research in this field continued and [http://www.bosslink.com/companys/1/default.asp?id=76800 Tianjin Rubber Research Institute] (also known as [http://www.redbiz.com.cn/company/gs04190822627.shtml Tianjin Municipal Rubber Industry Research Institute] (天津市橡胶工业研究所) was tasked to develop the rubber needed for the acoustic seeker casing. A team of 7 scientists including Shen Yingjun (申英俊), Hou Yehua (侯月华), Zhang Jianguo (张建国), Ma Gangying (马刚英), Zhang Lixia (张立侠), An Jiazhu (安家柱) and Zhang Suqin (章素琴) was formed, and eventually developed new rubber and production technique needed October, 1994, shortly before the Yu-6 program was fully resumed in 1995. The resulting rubber not only met the original requirement, but also exceeded it, with density reaching 1.098 ton per cubic meter, speed of sound reaching 1,551 metre per second, and surface roughness reaching 0.16 micrometer.

Propulsion system was the biggest obstacle in the development of Yu-6 torpedo. A team of three scientists including Ms. Su Li (苏丽), Mr. Mao Yuanfu (毛元福), and Mr. Wang Lisong (王立松) of [http://h.model.china315.com/web/h/r/b/d/t/y/j/s/ Harbin Electro Carbon Research Institute] (哈尔滨电碳研究所) was tasked to develop the graphite material used to make engine valves and other components. By September, 1998 the new graphite material designated as M130 had been successfully developed and then utilized for Yu-6 torpedo. The piston ring of the engine was developed successfully in December 2003 by [http://www.cypr.com.cn/ Yizheng Shuanghuan Piston Ring Co. Ltd.] (仪征双环活塞环有限公司). Mr. Wang Guozhi (王国治) was in charge of noise reduction and his successful research in this field resulted in wining a second place in the Chinese national scientific and technology advancement award in 1998.

Over two third of the technologies used for Yu-6 torpedo was new to Chinese, and there were some serious doubts that China could complete the project on its own. Mr. Dong Chunpeng (董春鹏), a University of Science & Technology of China graduate in 1966 and then worked for 705th Institute since was determined to succeed, and succeed they did, after developing 18 patents including in four fields that China had never had any experience. After ten years of development, Yu-6 torpedo was finally accepted into service in 2005, and for the success, Mr. Dong Chunpeng (董春鹏) was awarded 2006 Scientific and Technological Advancement Award in the end of February, 2006 in Beijing. One characteristic of Yu-6 torpedo is its high performance processor. In comparison to the Motorola 68000 or Intel 8086 microprocessors commonly used on most western torpedoes, the microprocessor used for Yu-6 torpedo is at least equal to the those of Intel 80486 class. Some domestic Chinese sources have claimed that Loongson-1 is used for Yu-6 torpedo, and the operating system is the Kylin operating system developed by the National Defense Science and Technology University, but this has yet to be confirmed by both the Chinese government and sources outside China. Another characteristic of Yu-6 torpedo is that the transducer array of its acoustic seeker has at least 55 transducers, more than that of US Mark 48 torpedo, which has a total of 52 transducers, but the exact number is not released. Yu-6 torpedo was also the first Chinese torpedo designed with the concepts of modular design and open architecture software programming in mind, so that when new technologies and programs become available, they could be readily incorporated. In comparison to the first generation Chinese wire guided torpedo Yu-5 torpedo which must be use acoustic guidance in the terminal stage or when the wire is severed, the wire and acoustic guidance can be switched from one to another at any time for Yu-6 torpedo. Furthermore, when the wire of Yu-6 torpedo is severed, the targeting information stored in the memory would enable the computer onboard to calculate the approximate new location of the target, augmenting the acoustic homing to achieve higher kill probability.

pecifications

*Diameter: 533 mm
*Guidance: passive / active acoustic homing + wake homing + wire guidance
*Propulsion: Otto fuel II
*Speed: maximum > 65 kt (for attack)
*Range: maximum 45 km+ (at the cruise speed)

External links

*http://www.sinodefence.com/navy/weapon/yu6.asp