# China’s Plan to Block All Submarines

Channel: Real Engineering
Source: https://www.youtube.com/watch?v=jiWtrVL4tmA
Recap page: https://rapidrecap.app/video/jiWtrVL4tmA
Generated: 2025-07-16T19:24:44.866+00:00

---
## Quick Overview

China is actively constructing a vast underwater sensor network, dubbed the "Great Underwater Wall," around its maritime borders, particularly near Taiwan, to detect and track stealthy submarines. This initiative is part of a global technological arms race where major naval powers are investing billions in advanced anti-submarine warfare (ASW) technologies, including sophisticated sonar arrays, magnetic anomaly detectors, and high-speed torpedoes, while also developing autonomous underwater vehicles (AUVs) that could fundamentally change future naval engagements.

**Key Points:**
- China is building a "Great Underwater Wall" of acoustic sensors around its maritime borders, particularly near Taiwan, to detect and track all submarines.
- This sensor network, costing an estimated $300 million, uses active sonar and passive hydrophones to precisely triangulate the position of underwater vessels.
- The US Navy's P3 Orion aircraft utilizes Magnetic Anomaly Detectors (MAD) and carries advanced torpedoes like the Mark 50, which employs a unique stored chemical energy propulsion system to avoid an exhaust wake.
- Soviet Alfa-class submarines, built with titanium hulls, were a Cold War mystery due to their unprecedented speed, deep-diving capabilities, and low magnetic signature, posing a significant challenge to Western intelligence.
- Future anti-submarine warfare is shifting towards autonomous underwater vehicles (AUVs) like Northrop Grumman's Manta Ray, which can operate silently, anchor to the seafloor, and recharge underwater, potentially making manned submarines obsolete.
- Space-based Synthetic Aperture Radar (SAR) satellites are emerging as a new ASW tool, capable of detecting submarine wakes from orbit, as demonstrated by recent Chinese satellite launches.

![Screenshot at 1:00: An animated map showing China highlighted in red, with Taiwan in blue, and red target markers indicating a sensor network around Taiwan and the Philippines.](https://ss.rapidrecap.app/screens/jiWtrVL4tmA/00-01-00.png)

**Context:** Submarines are critical assets for naval powers, offering stealth and strategic capabilities, but their hidden nature also makes them difficult to track and counter. The video delves into the ongoing technological race to either enhance submarine stealth or develop advanced anti-submarine warfare (ASW) methods. This includes examining China's ambitious underwater sensor network, the evolution of torpedo propulsion, and the use of magnetic anomaly detection, all set against the backdrop of increasing geopolitical tensions in regions like the South China Sea.

## Detailed Analysis

The world's oceans conceal an invisible armada of submarines, ranging from nuclear-powered ballistic missile vessels capable of immense destruction to stealthy attack submarines. These vessels operate beyond civilian sight and often accountability, as demonstrated by a recent Russian Kilo-class submarine incident in the Philippines' exclusive economic zone. In response to this hidden threat, major naval powers have invested billions in anti-submarine warfare (ASW) technologies. A key development is China's "Great Underwater Wall," a $300 million acoustic sensor network being built around Taiwan and extending across its maritime border. Operational since 2016 with sensors in Challenger Deep and off Yap, Micronesia, this network aims to detect and locate any submarine entering Chinese territory, potentially crippling an amphibious invasion of Taiwan. These active sonar arrays send sound pulses and receive return signals, while passive hydrophones simply listen for intruders. The video also explores other ASW technologies, such as the US Navy's Lockheed P3 Orion aircraft, which uses a Magnetic Anomaly Detector (MAD) to find submarines by sensing disturbances in Earth's magnetic field. While effective at low altitudes, MAD struggles with deeper-diving, non-ferromagnetic submarines. The Mark 50 torpedo, designed to attack deep-diving submarines, utilizes a unique stored chemical energy propulsion system (SCEPS) that avoids an exhaust wake, making it harder to detect. Historically, the Soviet Union's titanium-hulled Alfa-class submarines, built in the 1960s, presented a significant challenge due to their speed, deep-diving capabilities, and low magnetic signature, achieved through complex electron beam welding techniques. Looking to the future, space-based Synthetic Aperture Radar (SAR) satellites, like those recently launched by China, can detect submarines by analyzing their distinctive wakes on the ocean surface. Furthermore, autonomous underwater vehicles (AUVs) like Northrop Grumman's Manta Ray drone represent a paradigm shift, capable of continuous underwater patrols, silent electric propulsion, seafloor anchoring for listening, and even recharging from underwater hubs, potentially leading to a future dominated by swarms of electric submarines rather than traditional manned vessels.

### The Submarine Threat

- Oceans are home to an invisible armada of submarines, including nuclear-powered ballistic missile and attack submarines, operating beyond civilian sight and accountability
- Major naval powers invest heavily in detecting and destroying these vessels, as exemplified by a recent Russian Kilo-class submarine incident in the Philippines' exclusive economic zone.

### China's "Great Underwater Wall"

- China is constructing a $300 million acoustic sensor network, dubbed the "Great Underwater Wall," around Taiwan and its maritime borders to detect and locate stealthy submarines
- Operational since 2016 with sensors in Challenger Deep and off Yap, Micronesia, this network aims to prevent undetected entry into Chinese territory, potentially crippling an amphibious invasion of Taiwan.

### Acoustic Sensor Technology

- China's system utilizes active sonar arrays that send sound pulses and triangulate submarine positions, alongside passive hydrophones that listen for intruders
- This design prevents enemies from locating the sensors through their own sonar pings, enhancing stealth and effectiveness.

### Anti-Submarine Warfare (ASW) Aircraft

- The Lockheed P3 Orion is a primary US submarine hunting aircraft, equipped with a Magnetic Anomaly Detector (MAD) that senses disturbances in Earth's magnetic field caused by ferromagnetic submarine hulls
- While effective at low altitudes, MAD struggles with deeper-diving or non-ferromagnetic submarines, requiring the P3 to fly low in systematic grid patterns.

### Advanced Torpedo Propulsion

- The Mark 50 torpedo, designed for deep-diving submarines, uses a stored chemical energy propulsion system (SCEPS) with lithium fuel and sulfur hexafluoride oxidizer
- This unique system avoids an exhaust wake by storing combustion products, making the torpedo harder to detect and allowing it to operate effectively at extreme depths.

### Titanium Submarines

- During the Cold War, Soviet Alfa-class submarines, built with titanium hulls, presented a significant challenge due to their smaller size, lighter weight, increased strength, higher speed (40 knots submerged), deeper diving capabilities, and reduced magnetic signature
- The ability to weld large titanium structures, a feat Western nations struggled to replicate, gave the Soviets a major technological advantage.

### Space-Based Detection and Autonomous Drones

- Space-based Synthetic Aperture Radar (SAR) satellites can detect submarines by analyzing their distinctive wakes on the ocean surface, offering a new dimension to ASW
- Autonomous underwater vehicles (AUVs) like Northrop Grumman's Manta Ray drone represent the future of ASW, capable of continuous, silent underwater patrols, recharging from underwater hubs, and operating in swarms, potentially rendering manned submarines obsolete.

### Future of Underwater Warfare

- The development of autonomous, electric submarines that can anchor to the seafloor, enter listening mode, and operate without needing to surface, signals a shift towards a future dominated by unmanned underwater warfare, making traditional manned submarines a thing of the past.

![Screenshot at 0:00: Sunlight reflecting off the ocean surface, transitioning to underwater view with light rays.](https://ss.rapidrecap.app/screens/jiWtrVL4tmA/00-00-00.png)
![Screenshot at 0:05: A submarine appearing from the deep, illuminated by rays of light from above.](https://ss.rapidrecap.app/screens/jiWtrVL4tmA/00-00-05.png)
![Screenshot at 0:19: A large submarine moving through water, with people visible on its deck, creating a wake.](https://ss.rapidrecap.app/screens/jiWtrVL4tmA/00-00-19.png)
![Screenshot at 0:48: The conning tower of a submarine with an American flag flying, and crew members on deck.](https://ss.rapidrecap.app/screens/jiWtrVL4tmA/00-00-48.png)
![Screenshot at 1:00: An animated map showing China highlighted in red, with Taiwan in blue, and red target markers indicating a sensor network around Taiwan and the Philippines.](https://ss.rapidrecap.app/screens/jiWtrVL4tmA/00-01-00.png)
![Screenshot at 1:10: Text overlay "THE GREAT UNDERWATER WALL OF CHINA" over a blurred map of China and Taiwan.](https://ss.rapidrecap.app/screens/jiWtrVL4tmA/00-01-10.png)
![Screenshot at 1:29: An animated map showing China's two underwater sensors at Challenger Deep and Yap, Micronesia, with a blue arrow indicating a US naval movement path.](https://ss.rapidrecap.app/screens/jiWtrVL4tmA/00-01-29.png)
![Screenshot at 2:34: An animated cross-section of an island and surrounding water, showing an underwater sensor network connected to an onshore facility.](https://ss.rapidrecap.app/screens/jiWtrVL4tmA/00-02-34.png)
![Screenshot at 3:43: A yellow, torpedo-shaped underwater drone named "Talis" secured on a ship's deck.](https://ss.rapidrecap.app/screens/jiWtrVL4tmA/00-03-43.png)
![Screenshot at 4:17: A Lockheed P3 Orion aircraft flying in a clear blue sky, viewed from below.](https://ss.rapidrecap.app/screens/jiWtrVL4tmA/00-04-17.png)