SUPERCONDUCTING MACHINES AND GAS-TURBINE/ELECTRIC PROPULSION

The combination of the gas turbine with superconducting electrical machinery should be of particular interest for ship propulsion, and much of the paper is concerned with a consideration of the possibilities and advantages of such a combination for merchant and naval ships and smaller craft. Brief information is given on research and development activities in several countries (including the U.K. and, in particular, the U.S.A.) on superconducting machines for ships. The economics of propulsion systems employing superconducting machines are briefly discussed; they promise well for the near future. Several conclusions are drawn on the advantages of superconducting machines in propulsion systems in general and in combination with gas turbine prime movers in particular. Superconducting systems should be especially advantageous for such vessels as icebreakers, tugs, and ferries, and for hovercraft and hydrofoil craft. Hybrid installations are preferred, with a.c generators and d.c. motors; one generator should suffice for a single-or twin-screw installation. A d.c. homopolar propulsion-motor of 40 MW at 80 rpm is being built in the U.S.A.; only superconductivity could allow d.c. machines of this power. Order from: BSRA as No. 48,370.