Shipboard use of 400-cycle electric power

IN any discussion of 400-cycle electric power systems, the question comes to mind of why frequencies should be considered other than the established standard 60-cycle frequency now widely and most commonly used in electric systems ashore and afloat. Since 1932, 60-cycle a-c systems have been used in the majority of the ships' service electrical installations, particularly installations of large capacity. These have operated satisfactorily, and they served well during World War II. However, during and since this period the trend has been to increase the use of electric power, thereby increasing weight and space requirements of equipment out of proportion to the size of the ship, and to require improved performance of the equipment installed. The answer to this question can be summarized by the word “progress.” The purpose is to obtain better performance of electric equipment, or the same performance with less material, weight, and space. To achieve these goals, consideration must be given to the basic factors which influence electric equipment designs, one of which is frequency. Just as in other engineering fields where progress is being made by going to higher temperatures, pressures, and speeds, the use of higher frequencies opens up new avenues for electrical design improvements.