The ambition of making the journey from Shanghai to San Francisco in submarines in less than two hours has been proclaimed by the Harbin Institute of Technology. Sophisticated technological methods would be needed to allow for submarines to be propelled at high speeds.
Submarines tend to feature in marvel movies, or the likes thereof; and at other times, in war movies. These marine vehicles do have a mysterious touch to them since they are made to travel inconspicuously underwater. Recently, there have been talks of making them even more unnoticeable – by increasing their speed of travel. Currently, the fastest of them are made to run at speeds of around 130 km/h, and some (like the Russian supercavitating torpedo) can even reach 370 km/h. It has been reported that the Harbin Institute of Technology suggested to South China Morning Post (SCMP) to increase the speed such that submarines can go faster than jet airplanes.
The aim would be to travel from Shanghai to San Francisco in 100 minutes. How realistic is this project? Nothing has, as yet, been mentioned in scientific papers.
The mechanism behind such speeds is known as supercavitation – what Russians use to propel the torpedo at extremely fast speeds of hundreds of kilometers per hour. Supercavitation involves having the vessel surrounded by gas rather than liquid – the small bubbles which are formed around it as it moves are turned into one big bubble larger than the object itself. The vessel can thus move at faster speed than if it were to travel with the liquid surrounding it completely, causing drag which slows it down.
Keeping the effect of supercavitation ongoing is the challenge faced by those who wish to keep the fast speed sustained. The researchers of Harbin indicated that they have made a liquid membrane which would kill the drag effect, enabling the submarine to keep going at high speeds.