In oceanographic studies, by use of powered submersible research vehicles, speed is usually of slight concern, but it may be quite important to avoid noise, agitation of the surrounding water, or stirring of the ocean bottom materials.
For these reasons, propulsion by means of a system that derives its thrust by action upon a very large expanse of the surrounding sea is desirable. The electromagnetic propulsion system is eminently suited for such applications.
With secondary batteries of modern type, and use of a superconducting magnet, the performance, at the acceptable low speeds, of electromagnetically propelled research submarine vehicles is attractive from the range and efficiency standpoints, and gives the above mentioned advantages of silence and minimal disturbance. An example for a 15 ton submarine is given. Scaling relations are indicated to facilitate scale up or scale down from this size.
Though the electromagnetic method is attractive as a quiescent propulsion means, it poses certain other problems that must be dealt with in any future development program.