• Military Menu                       

• Introduction
• Systems
• Facilities
• Agencies
• Industry
• Operations
• Countries
• Hot Documents
• News
• Reports
• Policy
• Budget
• Congress
• Links

• WMD
• Intelligence
• Homeland Security
• Space

Fish Type 7 (Yu-7) Imitation MK46 torpedo

Since the 1950s, the Chinese Navy had not had light anti-submarine torpedoes. The Navy had successively had two types of air-dropped anti-submarine torpedo plans, code-named 816 and 753, prepared to be used on the Shuihong-5 water bomber. In October 1978, an unexploded American-made Mk-46 Mod 1 torpedo was collected by a Chinese fishing boat in the South China Sea. The torpedo was delivered to the PLA Navy for further research. But after acquiring the MK46, the 753, which was progressing slowly, was quickly abandoned. Around this treasure that fell from the sky, the research and imitation project code-named 109 was fully launched.

The torpedo was developed by the Xi'an Institute of Precision Machinery (705 Institute, a subsidiary of China Shipbuilding Industry Corporation) and Northwestern Polytechnical University (NPU), and was produced by the 872 and 874 factories.

This type of torpedo has been heavily equipped with Chinese naval surface ships and naval aviation aircraft, and used as a warhead for anti-submarine missiles. This type of torpedo has been equipped with a large number of surface ships and naval aviation of the Chinese Navy, and is used as the warhead of the Changying-1 anti-submarine missile. In the 1990s, YU-7 was equipped with almost all Chinese-made nuclear submarines. The torpedo has a diameter of 324 millimeters, a length of 2.6 meters, a total weight of 324 kilograms, and a warhead of 44 kilograms.

The guidance system is a combined active and passive voice guidance mode, which is extremely sensitive and reliable. It can play a role in both deep and shallow waters, and can even search for submarines equipped with anechoic tiles. Compared with other light torpedoes, this type of torpedo has the characteristics of high speed, long range, great power, etc., and the vehicle is flexible. Surface ships, airplanes and helicopters can be equipped and used.

On October 9, 1978, the militiamen of Wenchang County, Hainan Island caught an extremely heavy fish in their fishing nets. This is a late-production MK46 mod1 torpedo. It is inferred that it was a training mine that accidentally went out of control when the United States, which had just begun its "honeymoon period" with China, organized a maritime exercise in the South China Sea. The inspection of the torpedo was carried out under the codename 109 project and was carried out by the 705 Institute between December 1978 and April 1979.

In 1979, the Hainan militia fished out a second MK46 (perhaps on purpose...), and the domestic technical intelligence department also obtained a large amount of information, including a complete set of technologies for the latest improved MK46 mod5 tested at the Nnus Range in the United States. Report. This made the work of 705 Institute responsible for research and imitation work much easier.

In 1982, the PLA Navy decided to develop fish-7 on the basis of the reverse engineered MK-46. The 705 Institute is responsible for the overall design and development of the shallow water control system. Northwestern Polytechnical University is responsible for the development of deep-water control systems. Later in the 1980s, China purchased a batch of US-made MK46-II anti-submarine torpedoes for $80 million. The Yu-7 light anti-submarine torpedo is the product of China's reverse engineering of the American Mk-46 Mod 1 (Block 2). Yu-7 is based on 1960/70 Mk-46 technology and is considered an outdated model by today's standards. However, it is still the only side anti-submarine torpedo available to the PLA Navy.

The design was finalized in 1994. The Yu-7 program entered full-scale development in 1984, with more than 90 research institutes and factories across China actively participating in the program. Yu-7 consists of more than 5,000 accessories and 4,500 instruments. The design team drew 80,000 blueprints and more than 100,000 pages of technical documents. The first two prototype torpedoes were assembled at the 874 factory in December 1984 and tested on the Kunming (Kuming) 750 test platform in December 1985. In 1989, Yu-7 torpedoes have successfully tested 68 launches in four oceans.

The development of Yu-7 was severely delayed due to some major technical difficulties. In 1980, China formed a temporary ally with the United States and other Western countries to fight the Soviet Union. This provides an opportunity for China to seek some external assistance in the development of Yu-7. Although the Mk-46 technology transfer was far from complete due to the US arms embargo after the 1989 incident, some limited technical documents and a small number of Mk-46 samples were received and used to help Yu-7 develop.

After long-term reverse engineering research, the two samples were assembled, but a large number of related technologies such as the seeker still need to be solved. Project 109 ushered in a major turning point in 1985. China and the United States sent multiple delegations to each other to discuss torpedo weapons cooperation. The United States began to propose the establishment of an MK46 production line in China, and the contract amount was high.

This MK46 mod2 production plan, which has strict production quality requirements, is actually part of the "Big Arsenal Plan" of the then US Secretary of Defense Perry - it even includes the production of American equipment such as F-16 fighter jets and M1 tanks in China. The U.S. military only needed to arrive in China lightly equipped to use these weapons to fight against the Soviet Union. A few words, although when Perry and others formulated this bold plan, they also considered that they should have reservations in model technology to limit China's development; but it is certain that as long as they get this opportunity, China's military technology will Rapid progress at a speed that even Americans could not imagine. But this is all hindsight.

Perry took a group of American torpedo experts to visit China in 1985. The proud old Americans did not fully understand the progress of Project 109. As a result, they never expected that when they arrived at the torpedo testing site, they were greeted by a sailing performance of two sample mines whose sailing performance had reached the original level.

The basic version of Yu-7 has a total length of 2.86m, a weight of 230kg, a maximum speed of 40 knots, a maximum range of 9500m, a target capture probability of 90% under typical conditions, and a 45kg high-explosive warhead. The range (more than 14,000m) and speed (more than 45 knots) of subsequent improved models have been significantly improved.

After experiencing setbacks in early batch production quality (but at that time, the Navy only had two Type 052 ships equipped with Yu-7, which had little impact), the performance of Yu-7 stabilized in the late 1990s. Its export version is called ET-52 and is mainly equipped on the Pakistan Navy's F22P frigates and the Z-9EC anti-submarine helicopters they carry.

When it came to the development of the 7424 triple launcher supporting the Yu-7, it was inseparable from the contribution of the Pakistani Navy. During the visit of a Pakistani Navy frigate to China in the mid-1980s, the Intelligence Research Office of the 705 Torpedo Research Institute cooperated with naval professionals to organize careful investigation and mapping of the structure of the US-made MK32 launcher on the ship.

The B515 launcher (used to launch A244S torpedoes) introduced from Italy in 1987 also served as a reference. This launcher is only used on two Type 051G destroyers and 053H1Q (the 544 "Siping" ship). The seeker technology of the A244S also provides ideas for the development of the Yu-7. A244S was later equipped on the imported "Panther" and domestic Z-9C anti-submarine helicopters. The A244S with a pump sleeve at the tail is an electric torpedo, and its appearance is obviously different from the Yu-7 airdrop type equipped later. Each improved version of the Yu-7 has a matching airdrop model and an A244S universal pylon.

However, due to the limited load capacity of these helicopters, they can only carry one air-dropped torpedo, which seriously restricts the effectiveness of aviation anti-submarine warfare (for comparison, the Ka-28 can carry two Russian-made APR-3E anti-submarine torpedoes). The latest Gaoxin-6 anti-submarine patrol aircraft in service can carry about 10 Yu-7 series or the latest anti-submarine torpedoes.

Since the baseline model of the Fish-7 is only the MK46mod2 that was at the level of the United States in the 1970s, the development of the improved model began when the basic model was completed. In the late 1990s, the comprehensively improved Yu-7B was successfully developed and fully refitted the troops; while the Yu-7C is the latest improved version that utilizes some of the technological developments of the new generation of anti-submarine torpedoes.

Since the baseline model of the Fish-7 is only the MK46mod2 that was at the level of the United States in the 1970s, the development of the improved model began when the basic model was completed. In the late 1990s, the comprehensively improved Yu-7B was successfully developed and fully refitted the troops; while the Yu-7C is the latest improved version that utilizes some of the technological developments of the new generation of anti-submarine torpedoes.

The imitation work of the MK46 torpedo was of great significance to the Chinese navy. In particular, its research and development of Otto fuel played an important role in promoting the development of the Yu-6 thermodynamic submarine-launched dual-plane wire-guided torpedo aimed at the MK48. The successful development of Yu-6 and Yu-7 also marked that China's torpedo development began to break away from the former Soviet Union's line, laying the foundation for a new era of independent development of China's torpedo industry.

The most important one is the mastery of Otto thermodynamic technology, which promotes the development of the Yu-5, and its advanced active-passive combined acoustic guidance. The model also provides a good choice for the Chinese Navy to develop new torpedoes and improve old torpedoes. In addition, this light torpedo has also solved the major problem of the Chinese navy's development of anti-submarine missiles.

It uses advanced Otto fuel. The thermal power propulsion system has a maximum speed of 45 knots and a maximum range of 11 kilometers. The guiding system is a passive combined sound guiding mode, which can be used in both deep water and shallow water. The imitation work of the MK46 torpedo is of great significance to China. It not only provides the Chinese navy with a very advanced light anti-submarine torpedo, but also greatly enhances the anti-submarine warfare capability, and has made the development of Chinese torpedo technology a big step forward.

The MK46 torpedo equipped by the Chinese Navy still has a gap in performance. China's imitation of MK46 is an early model. So far, MK46 has developed five derivative models, and the latest model has evolved into MK50. Therefore, the MK46 torpedo equipped by the Chinese Navy still has a gap in performance with the most advanced model.

The Yu-7 torpedo is designed to launch from surface warship torpedo tubes to attack enemy submarines. The torpedo uses a two-speed, reciprocating external combustion engine using a single propellant (Otto) liquid fuel with a maximum speed of 43 knots. The torpedo is equipped with a 45 kg warhead and uses active and passive sound-homing guidance.

However, the Chinese imitation MK46 is an early model, and its performance is not the best. The Chinese Navy is also using its new technology to continuously improve. At present, this type of torpedo has been heavily equipped with various types of surface ships and naval aviation of the Chinese Navy. The main vehicles are escort ships and their ship-borne anti-submarine helicopters.