Kerosene Future Fuel for Steamship Propulsion; Electricity Will Dispel Fogs, Says Nikola Tesla

TWENTY-FIVE years ago marine engineers and architects were convinced that steam navigation, so far as construction for comfort, safety and speed was concerned, almost had reached its maximum of attainment, yet ten years later so many improvements had been introduced and speed was so greatly increased that experts agreed steamship building was yet in its infancy.

To-day the ocean can be crossed in less than five days, but engineers, instead of believing the limit of speed has been reached, say the best record made so far can be cut almost in half. The "thousand-foot ship," now considered a dream, in the next few years will be regarded as nothing unusual.

What the steamship of the future will be is largely a matter of guesswork, but many theories have been advanced as to what improvements it will show.

Nikola Tesla, whose work in electricity has interested the scientific world, talked recently with a representative of The Sunday Press on possible developments in steamship construction.

"One of the Important factors in propelling the steamship of the future will be compressed air," said Mr. Tesla. "The steam motor is bound to be superseded by the Internal combustion engine. This will require compressed air. The change, however, will come slowly, not only on account of the enormous capital invested, but because the full possibilities of steam have not yet been brought out.

Air Burned with Fuel.

"I need point out only the employment of superheat in connection with turbines which places the steam motor on a par in efficiency with the internal combustion engine. In the latter the air is burnt with fuel. The result is the production of mechanical force through expansion. Compressed air itself is used as a motive medium, but only in the operation of auxiliary machines on vessels and this field is therefore circumscribed.

"Could liquid air be used for propulsion? That is a question often asked. In answer I would say that it could, but its high cost and the comparatively low efficiency of the apparatus required prohibit its use.

"Machinery is now being perfected with which it will be possible to manufacture liquid air cheaply and in large quantities. It is not impossible that the next few years may see great development in the use of liquid air.

"Kerosene as fuel is likely to play an important part in future navigation. Experts at present are trying to devise a proper system of carburation which will make kerosene as useful as gasoline.

Kerosene is of smaller heating power and the necessary engines are slightly less economical, but it is safer and much cheaper. At present there is produced in the United States not less than 8,000,000,000 gallons per annum, while the production of gasoline is comparatively insignificant in quantity.

Kerosene Coming Fuel.

"This consideration alone will compel the employment of kerosene in place of more expensive fuel. It can be predicted, then, that from kerosene will be largely derived the future power for ship propulsion.

"As to the contention that the screw is the best device for propelling a vessel, I do not think this is true, although the screw is the best known device for putting in motion the largest body of water with the least velocity.

"This is an essential requirement for high efficiency under present conditions, but if very much higher speeds are attained, the screw propeller will have to be discarded and jet propulsion adopted.

"There is a curious prejudice in the minds of engineers in regard to this, the majority believing propulsion by jet is hopelessly inefficient. It is a fact that the jet is more efficient than the screw propeller under suitable conditions.

"One feature of the future ship that will be of great interest to the traveler who is a 'poor sailor' will be the prevention of rolling and pitching. Engineers are now at work and have succeeded to some extent in perfecting a device that will keep a vessel fairly steady even in the roughest weather.

"Vessels may be made perfectly steady by properly applied gyroscopes, but in a large steamer the stresses imposed on the bearings would be so great as to endanger the structure. Another principle which is now being tried with success depends on large chambers partly filled with water. They counteract the sudden motions of the ship.

Dispelling Fogs.

"I have been often asked if anything will ever be discovered that will dispel fog at sea — that is, in the immediate vicinity of a vessel under way.

"I am confident this can be done by means of electricity, and I have spent years experimenting and devising apparatus for this purpose. Dr. Oliver Lodge of England has also attempted the same thing, but our methods are entirely different. If this result is accomplished in a practical manner it will prove of immense value in the navigation of the seas.

"As to how far simplicity can be obtained in machinery propelling vessels I unhesitatingly say if wireless energy can be made available there will be nothing needed on a vessel except an electric motor, a machine of ideal simplicity. But a vessel also can be propelled without any machinery whatever in the ordinary sense of the term; that is to say, there need be no moving parts. Many years ago a German engineer took out a patent on this method of propulsion, and I have myself spent a great deal of thought on the subject, but have satisfied myself that no high economy can be secured. The propelling apparatus consists simply of one or more ducts or tubes under the water from which the water is periodically expelled by steam or gas under pressure.

"While I do not believe this method will ever be made practical, it is not impossible it might be applied in several instances. I think, though, in supplanting the water propeller by an air propeller a useful type of vessel will be produced. Such a vessel will be suitable for navigating shallow rivers and propelling rafts and such purposes."