https://www.theregister.co.uk/2017/10/27/chinese_navy_silent_magnetic_propulsion/

Chinese whispers: China shows off magnetic propulsion engine for ultra-silent subs, ships

Inshert Hunt for Red October jokesh here

The Ministry of National Defense of the People's Republic of China this week reported the first successful test of a magnetohydrodynamic drive that could let ships and submarines sneak around almost totally silently.

The system, built by the imaginatively named state-owned China Shipbuilding Industry Corporation, was apparently fired up for its first test on a naval vessel at 11am on October 18, and the vessel reached "the designated speed" for the tests.

Magnetohydrodynamic drives aren't new: they have been tested for decades, but were largely abandoned for being too slow and power hungry. The devices work by electrifying water and then using powerful magnetic fields to propel themselves.

In 1992, the Japanese built a working magnetohydrodynamic drive into a test ship, the Yamato 1, however, it was judged too inefficient to be practical. The ship used liquid helium-cooled superconductors to get up to speeds of 15KPH (9MPH) and later prototypes couldn't beat that speed.

Because no moving parts are involved, the system is pretty much silent running but for the sound of water. As a result, it could be perfect for stealthy submarines or naval ships doing secretive work. The Chinese government claims the hardware has already been patented and further testing will be carried out before it is deployed.

If this is all true, the drive will be sad news for the US Navy, which for years has been claiming superiority in silent submarine technology. A practical magnetohydrodynamic drive from the Chinese could change all that. So, what's next? Fleets of sonar drones hunting for… oh, wait.

https://www.theregister.co.uk/2015/11/12/us_military_drone_submarine_hunter/