[Popular Science of Chinese Military Technology] Active underwater defense against torpedo attacks, how powerful is the anti-torpedo torpedo?

Torpedoes have posed a huge threat to surface ships since their birth. With the development of technology, modern torpedo weapons for surface ships and submarines have become more and more perfect and intelligent, making it increasingly difficult for warships to resist. In order to prevent expensive surface ships and submarines from being attacked by underwater threats, navies of various countries are constantly seeking various methods. Anti-torpedo torpedoes use hard kill measures to directly destroy incoming torpedoes. They can be said to be an extension of the anti-missile concept in the underwater combat space and an effective means of ship defense. Therefore, they have great development prospects.

"Cannibalistic" anti-torpedo torpedo

At present, anti-torpedo torpedoes basically use small torpedoes. However, to use small torpedoes to reliably counter torpedoes, many problems need to be solved. First, anti-torpedo torpedoes must have better self-guiding performance, because the engagement process of intercepting torpedoes is very short, and the reduction in torpedo diameter directly leads to a reduction in the diameter of the self-guiding system's ring energy array, which requires the self-guiding system to increase the working frequency of the self-guiding. Second, anti-torpedo torpedoes must have higher strike accuracy, because small-diameter torpedoes will directly lead to a reduction in the amount of explosives and shorten the torpedo's damage radius. Third, small torpedoes cannot accommodate powerful power systems, which will directly affect the speed and range of anti-torpedo torpedoes. How to strike a balance among various performances is the key.

Torpedoes are a powerful weapon in naval warfare that can achieve great results with small means (Image source: NetEase)

In actual combat, after receiving a torpedo alarm, the anti-torpedo torpedo system first identifies and classifies the alarm information, and then locates the target, so that the fire control can provide a solution for the anti-torpedo torpedo system to intercept. At the same time, the anti-torpedo torpedo system is prepared for firing, and the anti-torpedo torpedo is launched when it reaches a certain range. After entering the main course, the anti-torpedo torpedo searches, and after finding the target, it enters self-guidance and detonates the warhead at the closest point to the target, thereby destroying or rendering the incoming torpedo ineffective due to shock. At present, some countries have developed their own anti-torpedo torpedoes.

Underwater active defense system for ships

For example, the United States has developed the SMART anti-torpedo torpedo. This type of anti-torpedo torpedo has a caliber of 160mm and a length of 2.8m. After being put into service, it is 2.67m, with a range of 10km, a speed of 30-40 knots, a charge of 5kg, an interception range of 4.5km, and can fire multiple torpedoes at once. After the explosion, it can cause hard kill torpedoes within a range of 20m, and can intercept various torpedoes that are direct, acoustically guided/wire-guided, and wake-guided. SMART is equipped with a multi-mode homing head, and the power system uses a propulsion system that stores chemical energy for propulsion, which is powered by the reaction of lithium and sulfonamide hexafluoride.

Anti-torpedo torpedoes use hard kill to destroy incoming targets (Image source: Baijiahao)

At the end of 2022, Atlas Elektronik, a subsidiary of Germany's ThyssenKrupp Marine Systems, launched an anti-torpedo torpedo called "Sea Spider". The "Sea Spider" is a standard cigar shape, about 2m long and 210mm in diameter. The missile body is divided into four compartments: the tail compartment where the nozzle and rudder are located, the solid-fuel jet engine compartment, the warhead compartment, and the guidance compartment. The guidance compartment contains a sonar-based self-guidance system, an inertial measurement unit, and a high-performance computer. In combat, the sonar will monitor the depths of the ocean, and all sounds and water fluctuation parameters will be transmitted to the shipborne equipment for analysis. When a torpedo-specific signal appears, the corresponding data will be sent to the computer of the anti-torpedo weapon. It only takes a few seconds from determining the signal to launching the "Sea Spider", and then the "Sea Spider" computer will figure out the changing position of the torpedo and intercept it.

In addition, DSIT, which is controlled by Israel's Rafael Advanced Defense Systems, has also launched its new anti-torpedo system "Torpedo Killer". The system is suitable for submarines and mainly consists of a side-array sonar system and anti-torpedo ammunition. The anti-torpedo ammunition used by the "Torpedo Killer" has both decoy and killing functions. When it is far away from the submarine, it uses acoustic signal interference to lure the torpedo, and when it is close to the submarine, it can directly destroy the torpedo. At the same time, DSIT is also developing an anti-torpedo system for surface ships, which can be launched using existing surface ship rockets or missile launchers.

About the author: Lan Shunzheng specializes in research and theoretical writing on space strategy, military strategy, and international relations. While serving in the army, he edited and published his first military theory book, "Random Thoughts on National Defense by an Army Sergeant - Soldiers Going Out of the Frontier". While studying for a master's degree at the School of International Relations, he focused on space strategy. Now he often publishes related articles on online media and military magazines. In addition, his second monograph, "Zhenxing Dinghai - Building China's Future Space Military Strategy", has also been published.

Produced by: Popular Science of Chinese Military Technology

Producer: Guangming Online Science Department

Author: Lan Shunzheng (military science writer)

Scientific review: Fei Boyu (senior military content editor)

Planning: Jin He