Chinese researchers have announced that they have made a breakthrough that brings the development of a supersonic submarine one step closer to reality, using a special liquid membrane to reduce the friction that the surrounding water would create on the craft.

Due to the high density of water, the speed of conventional submersibles is severely limited, unless a technique called ‘supercavitation’ is used. Developed by Soviet researchers during the cold war, the concept requires the continuous generation of a bubble of air around the submerged craft, of which drastically reduces the drag that would otherwise slow the craft down. So far, this technique has only been applied to smaller devices, such as torpedoes, as supercavitation requires the craft to be traveling at around 100km/h before it will work. This technique enabled the Russian ‘Shkval’ torpedo to reportedly be able to travel at speeds of 320 km/h.

However, researchers at China’s Harbin Institute of Technology have developed what they refer to as a “special liquid membrane”, that would reduce a craft’s friction at lower speeds, allowing it to build up to a speed where the supercavitation effect could be started. This would allow larger craft to use the technique, allowing for a 3,320 mph submersible, that could cross the Pacific in 100 minutes. While there are more advances that need to be made to make a craft like this a reality, such as a sustainable rocket motor that could maintain high speeds for a long time, this liquid membrane technology is a major step in increasing the speed of submarine craft.

However, the accuracy of this story is controversial. Some analysts believe that the Chinese announcement has been misinterpreted, and that a submarine that moves that fast is physically impossible underwater, even with the boat surrounded by an air cavity. Also, guidance is an issue, but Professor Li Feng Chen, who is working on the project, says that they have developed promising technology that would enable the vessel to turn.

The image associated with this story is of a Shkval Torpedo.