The circular form of the linear superconducting machine for marine propulsion

The superconducting linear synchronous machine (LSM) has been shown to be a highly efficient means of propulsion for application to advanced ground transport systems. We have shown that it would also appear to have significant advantages in marine engineering, e.g. for the propulsion of large commercial ships, tankers and military vessels, where the basic requirements of high torque at relatively low shaft speeds, together with the ease of reversibility, are readily met. A design utilising the circular form of the LSM as a ship´s drive motor has been proposed and the details of a specific form of the LSM, namely the linear commutator machine (LCM) are discussed. The many advantages of this type of heteropolar machine are listed and compared with the superconducting homopolar motors which have been developed for ship propulsion. In particular, its flexibility in design, the built-in redundancy factors, hence reliability, together with other design details of the cryogenic magnets and the armature winding are described.