China’s Fully Stealth Frigate Conducts Sea Trials – Nemesis of Unmanned Attack Boats

In addition to the trials of the Fujian carrier, Type 054B and 075 ships have also undergone recent sea trials, and there are also sea trial images of a newly built frigate (rumored to be named Type 059) at shipyards in the north. This ship is larger than Type 056 but smaller than Type 054, similar in size to Type 053, with a cruising speed of around 28 knots and employing a concealed exhaust outlet. This method can only use diesel engines, with little possibility of gas turbines.

Nemesis of Unmanned Attack Boats

From the perspective of its usage, this ship is mainly for coastal operations. Currently, the main force of the Chinese navy is towards larger and more ocean-going vessels, but China has a long coastline with many vessels. The green dots in the image below represent real-time ship positions, and the density of vessels is very high. Large ocean-going vessels cannot fully utilize their capabilities here. The maritime and aerial battles everyone wants to see might not necessarily happen, but close-range friction and jostling are frequent occurrences. Engaging in this kind of activity requires a balanced offensive and defensive firepower, rapid firepower output, and the ability to both attack, defend, and evade. High stealth capabilities allow the ship to conceal itself when engaging the enemy and quickly hide among surrounding vessels after the attack ends.

Although the existing Type 022 missile boats are fast, they primarily use a clustered approach to launch anti-ship missile attacks on large ships, with limited range and endurance. The Russia-Ukraine war also demonstrated that in coastal conditions, large ships are vulnerable to attacks by drones and unmanned boats. The new frigate is equipped with phased array radars, electro-optical fire control systems, sonar systems, unmanned reconnaissance aircraft, close-in defense missiles, and stealth ship guns, making it very suitable for dealing with these small, slow targets.

Based on the unmanned boat attack videos released by the Ukrainian side, unmanned surface combat boats typically attack in groups of 6-10, with a reserve force waiting at a distance of 2000-3000 meters for the initial attack result. During the attack, the main focus is on concentrated strikes against the target ship. Once a target is hit, the ship slows down, its defensive capabilities weaken, and subsequent attacks by unmanned boats render it completely ineffective. The warheads carried by unmanned surface combat boats may exceed 200 kilograms. During the final approach (terminal maneuvering), unmanned surface combat boats accelerate to high speeds and perform S-shaped maneuvers of +/- 30-45 degrees, minimizing the possibility of being detected, locked onto, and hit by defensive firepower.

When the Ivanovets was attacked, it engaged in combat with Ukrainian unmanned surface combat boats using its AK-630 close-in weapon system, which has a high rate of fire (30mm, 4000 rounds/minute), but with large shooting dispersion. According to the video, the hit rate against maneuvering unmanned boats was low.

The Ivanovets had outdated electronic equipment and detected the Ukrainian unmanned surface combat boats when they were relatively close. Coupled with the high speed of the unmanned surface combat boats, there was not enough time for defensive reactions. The AK-630 fire control system was outdated and could not effectively counter multiple approaching unmanned surface combat boats simultaneously.

Unmanned surface combat boats are capable of sinking large ships. When combined with current intelligence and other capabilities, these weapons can affect the course of naval operations. After repeatedly using this tactic, Ukraine sank several Russian ships, and similar low-cost unmanned boats may soon be used by other countries.

The project for the new frigate was certainly initiated before the Russia-Ukraine war, so it can be said that the military had a clear understanding of such small, slow targets long ago. Stealth, high-performance radar, various shipborne weapons, and high maneuverability are effective ways to deal with these irregular weapons. Facing such attacks during sea trials should also be an important aspect.

Enhancing the stealth capability of ships verification

The Zumwalt-class destroyer can be said to be a type of large surface warship with relatively thorough stealth characteristics. Everyone is working on stealth, but the key is to what extent stealth should be achieved to be most reasonable, especially since large warships are inherently large targets, reducing radar cross-section comes at a high cost. The Zumwalt-class destroyer costs $4.5 billion with a displacement of 14,000 tons, and its radar cross-section is said to be equivalent to that of a hundred-ton fishing boat. All external devices are covered, even the ship’s guns are stealthy in structure, leading to the high cost of the first ship. This number far exceeds that of similar warships.

The high cost is mainly due to the development and application of stealth technology, as well as the selection and processing of stealth structures and materials. While pursuing stealth performance, the Zumwalt-class destroyer has paid a heavy price in terms of cost, and even a general-purpose navigation radar on a hundred-ton fishing boat can detect it in good weather conditions at a distance of about 15 nautical miles.

Is this enhancement of stealth capabilities worth it? This involves the issue of cost, performance, and the balance of actual combat. On the one hand, enhancing stealth performance will undoubtedly improve the survivability and combat effectiveness of warships, giving them more advantages on the battlefield. On the other hand, the high cost also increases the procurement and maintenance costs of warships, which may affect the overall scale and combat capabilities of the fleet.

The verification of the stealth capability enhancement of ships needs to be comprehensively evaluated from multiple perspectives. In theory, the improvement of stealth performance can be predicted through simulation calculations, but the actual situation is often more complex than theory. In maritime combat scenarios, warships need to deal with various uncertainties, so it is particularly important to build a verification ship to test the actual effects of stealth performance.

Through the testing of verification ships, the actual performance of enhanced stealth capabilities can be more accurately assessed. If the verification results show that the stealth effect is indeed significant, then this technology will be widely used on future large warships, bringing a qualitative improvement to the naval combat capability. Conversely, if the verification results are not ideal, it is necessary to re-examine the direction of stealth technology development and find a more reasonable balance between cost, performance, and actual combat.


The verification of enhanced stealth capabilities is an important issue. China needs to fully consider the issues of cost, performance, and the balance of actual combat while pursuing stealth performance, in order to promote the continuous development of naval equipment technology. This should also be the main task of the new stealth frigate. (Zhang Gong)

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