A cool way to save ships

摘要

Shipping has been waitingfor some time for high-temperature superconductor HTS motors, with their promised weightsavingsand improved efficiency, but now a new marine use has been found for the technology. Degaussing of ships used to be something that was done on a regular basis to combat the risks posed by magnetic mines left overfrom the Second World Waror laid in more recent conflicts. A more permanentsolution was to install copper coils inside the hull through which a current was passed. Either process prevented the steel of a ship's hull from concentrating the Earth's magnetic field and thus made it less likely to activate mines. Mines have been the cause of 77 of US Navy ship casualties occurring since 1950. Most recently, the modern warships USS Samuel B. Roberts, USS Princeton and USS Tripoli sustained severe damagefrom mines during conflicts in the Gulf. Last year, the US Navy tested a new system in conjunction with American Superconductor and cable manufacturer Nexans using superconducting ceramic materials, instead of traditional copper cables, to neutralise the magneticsignature of the ship.