September 1, 2005

The U.S. Navy has built a 133 foot long scale model of a future warship, the Sea Jet, to test how well all electric drive, and to test the use of an all water jet propulsion system. The water jet system used, AWJ-21, was designed by Rolls Royce Naval Marine corporation. Water jet systems have been used as auxiliary propulsion systems for decades. But the U.S. Navy wants to replace the conventional rudders and (screw) propeller completely with a water jet system. The tests will be conducted in an Idaho lake. After the AWJ-21 tests are completed, the Sea Jet will have the water jet system removed, and another new propulsion system, RIMJET, installed and tested. RIMJET is a conventional propeller mounted in a pod, that is mounted outside the ship. The pods contains an electric motor the drive the propeller. The purpose of both these tests is to find out if the new systems will make the ships quieter and more nimble, especially in coastal waters. The navy wants to begin building all electric ships within the next decade. This is especially urgent with the recent development of more efficient laser cannon, which need large amounts of electricity for their ammunition.