US Navy orders $8m sea-going super motor

The US Navy`s Office of Naval Research (ONR) has placed an $8m order for a 6,500hp (4.85MW) high-temperature superconductor (HTS) ship propulsion motor that could begin sea trials before the end of next year.

The AC synchronous motor will be built by the American Superconductor Corporation (ASC), which recently completed tests on a 5,000hp (3.73MW) HTS motor.

ASC says that the Navy motor, operating at 230 rpm, will have ten times the torque of the 5,000hp, 1,800 rpm test machine. It sees the high-torque, low-speed motor as being a critical milestone on the path to 20,000hp and 35,000hp motors that will be needed to propel electric warships. These machines will occupy one-fifth of the space of conventional motors and will allow ships to travel faster, or to carry more cargo or passengers.

"This is the first HTS motor designed specifically for ship propulsion," says ASC chief executive, Greg Yurek. He adds that the high power densities and efficiencies of the HTS motors, will allow ship designers "to create new types of ships not possible with conventional motor technology".

ASC is scheduled to deliver the 6,500hp motor and drive system (based on commercial technology) by next summer, and hopes to start selling commercial versions in 2004. It says that HTS motors of this size could be used to propel vessels such as container ships, ferries, and tankers.