Shanghai to San Francisco in 100 minutes by Chinese supersonic submarine
Chinese eye 'supercavitation' technology as future of underwater travel. ● China has moved a step closer to creating a supersonic submarine that could travel from Shanghai to San Francisco in less than two hours. New technology developed by a team of scientists at Harbin Institute of Technology's Complex Flow and Heat Transfer Lab has made it easier for a submarine, or torpedo, to travel at extremely high speeds underwater. Li Fengchen, professor of fluid machinery and engineering, said the team's innovative approach meant they could now create the complicated air "bubble" required for rapid underwater travel. "We are very excited by its potential," he said. Water produces more friction, or drag, on an object than air, which means conventional submarines cannot travel as fast as an aircraft. However, during the cold war, the Soviet military developed a technology called supercavitation, which involves enveloping a submerged vessel inside an air bubble to avoid problems caused by water drag. A Soviet supercavitation torpedo called Shakval was able to reach a speed of 370km/h or more - much faster than any other conventional torpedoes.