China’s New Unmanned Attack Sub May Not Be What It Seems

China has apparently declassified details of a 2010 exercise in which an unmanned submarine detected, tracked and engaged a target submarine with a torpedo in the South China Sea, all without human intervention. This suggests a highly advanced capability, and disclosing it at a time of increased tension over Taiwan sends a definite signal. However, everything here may not be as it seems.

The South China Morning Post (SCMP) broke the story Wednesday, with details of work by Professor Liang Guolong and colleagues from Harbin Engineering University, “China’s top submarine research institute.” The SCMP notes that the work was declassified with the publication of a paper in the Journal of Harbin Engineering University describing the test of an unmanned underwater vehicle (UUV) in the Taiwan Strait.

The drone submarine carried out a pre-programmed patrol route until it encountered a target emitting sounds simulating an enemy submarine. The drone sub then went into engagement mode, leaving its patrol route, activating its sonar and directing the beam to track down the intruder.

“One torpedo fired by the drone hit the simulated submarine,” according to the SCMP. “For safety reasons, the torpedo was not loaded.”

While this implies that a real torpedo was fired, academic researchers would not normally handle military hardware. This would usually only be used at much later engineering stages. Given that the object of the test appears to have been to validate the unmanned sub’s autonomous sensor capability, the torpedo itself may also have been simulated … though of course revealing this would make the story far less impressive.

The SCMP has previously published stories about other supposedly world-beating new Chinese technology like super-powerful military radar, a quantum computer a million times more powerful than Google’s and even a laser assault rifle. This story may be a similar puffing up of basic research suggesting an actual capability.

Another reason for caution is that the paper referred to does not appear to be in the current listing of Journal of Harbin Engineering University as claimed, or any previous issues, and searches of other Chinse journals did not turn up any similar paper. The SCMP has not responded to my request for comment or clarification.

Professor Liang Guolong does have a track record the field of underwater sound engineering, though. He published a paper in 2018 (eight years after the supposed test) describing a new sonar suitable for unmanned underwater vehicles. This uses a smart, self-adjusting, self-steering arrangement to replace the human sonar operator and their skill to pick out traces of a target vessel and point the sonar in the right direction. However, the 2018 paper describes a relatively unsophisticated capability compared to the complete end-to-end engagement in the phantom new paper. Current work may be at a much earlier stage than the SCMP report suggests.

David Strachan, senior analyst of Strikepod Systems, notes that great power competition often involves revealing new information to keep your adversary off balance but without giving away too much, and this places the story in some doubt.

“A capability like this would be significant, and, if true, presumably not something Beijing would want to reveal,” says Strachan. ”In general, undersea warfare capabilities are some of the most closely guarded secrets by navies worldwide, so why Beijing would choose to reveal this is a bit of a mystery, and quite honestly calls into question the veracity of the claim.”

On the other hand, China certainly does have existing unmanned underwater weapons.

“What some may not realize is that China has had the capability to autonomously detect, identify, classify, and engage undersea targets for decades in the form of multi-influence sea mines, including encapsulated torpedo mines,” says Strachan.

These are the Chinese equivalent to the U.S. Navy’s new Hammerhead mine, which lies on the sea bed and uses sonar and other sensors to track vessels and submarines. When it spots an approved target, it fires a Mark 54 Lightweight homing torpedo. A mobile UUV would represent a real stepping up of this capability.

China is developing large and possibly torpedo-armed robot submarines, but none were known to be in service back in 2010. A 2019 military parade included trucks carrying previously unseen HSU-001 autonomous underwater vehicles, the Chinese version of the Boeing Orca XLUUV that has been under development since 2017.

It is worth noting that the U.S. is also working on the sort of sort of capability that the Chinese claim to have developed. Under a classified project known as CLAWS, unmanned subs will have AI capable of evading opponents, finding targets and deploying “kinetic effects” (such as torpedoes) against them.

Naturally, such developments raise serious questions about autonomous weapons choosing their own targets. But as this is what sea mines already do, the debate in the underwater realm is much less contentious.

“How close is China to operationalizing a viable, combat-capable XLUUV?” asks Strachan. ”Given the complexity of the operating environment, and the myriad issues surrounding autonomy and artificial intelligence, I’m inclined to believe that it remains elusive.”

The release comes at a time of increased tension and increased Chinese rhetoric and military operations near Taiwan, and when the U.K. is sending its new aircraft carrier to the region in a move decried by the SCMP. It cannot be a coincidence that the SCMP report mentions that the test took place “in or near the Taiwan Strait.”

Strachan notes the secrecy that surrounds the U.S. and U.K. efforts to develop large fully autonomous unmanned underwater vehicles capable of carrying torpedoes or mines. When they do develop this kind of capability, he says the one thing that is certain is that they will not publicize it.