Researchers at the Harbin Institute of Technology, in northeast China, have been looking into the same technology that allowed the Russian Shakval torpedo to reach speeds of around 230 m.p.h. Through supercavitation, the process of enveloping a submerged vehicle in an air bubble to minimize friction, a submarine could, in theory, travel at the speed of sound (3,603 m.p.h.).

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Supercavitation possibilities

The problem with supercavitation is maneuverability or just being able to steer the submerged vessel. However, the team from Harbin is claiming that they have solved this problem by having found a way for the vessel to shower itself with liquid while traveling inside the created air bubble. This would create a membrane on the surface of the submerged vessel that could, in theory, be manipulated in order to steer it.

“We are very excited by its potential,” said Li Fengchen, professor of fluid machinery and engineering at the Harbin Institute’s complex flow and heat transfer lab. “By combining liquid-membrane technology with supercavitation, we can significantly reduce the launch challenges and make cruising control easier,” he told the South China Morning Post.

Supersonic submarine: Not going to happen

Li does point out that this is a long ways to becoming a reality. A criticism that is mild compared to other doubters.

“The idea that any Chinese research association would talk about its best ideas is ludicrous beyond words,” says physicist and naval weapons expert Norman Friedman, of the U.S. Naval Institute. “They simply don’t go public with this kind of project, though they do sometimes show off things that don’t exist.”

At the end of the day, this sub isn’t going to happen any day soon. Even by manipulating the membrane in order to steer, it’s simply too risky. If at any point that the ship breached the air bubble created by supercavitation due to the efforts to steer it, it would immediately snap off at the speed suggested due to the difference in density. And that’s just not much fun when traveling underwater at around 3,700 m.p.h.