The Tesla Turbine (September 30, 1911)

The accompanying illustrations which were taken at the request of the editor of this journal, give a very good idea of one of the small Tesla turbines which have been built and operated with slight changes of the rotors and accessories as steam, gas, air and water turbines or rotary engines, and also as pumps and compressors. The characteristics and the mechanical principles involved in the construction and operation of the Tesla turbine were discussed comprehensively in the Electrical Review and Western Electrician of September 9. Through the courtesy of the New York Edison Company the machine illustrated was installed at its Waterside station where long-continued tests were carried on under greatly varying conditions.

Mr. Tesla, when seen on Tuesday of this week by a representative of the Electrical Review and Western Electrician, gave the following statements respecting the operation and economy of his turbine:

"The turbine has readily developed 110 horsepower with free exhaust, but this does not convey even an approximate idea of the possibilities offered in power production by the new principle of propulsion. It would not have been difficult to develop twice as much power were it not for the torsional stress to which the shaft was subjected. However, even with the result attained, bearing in mind that the rotor weighs only twenty pounds, and that the casing itself could have been pressed steel sheet, the weight of which together with the bearings would not exceed thirty pounds, a performance of more than two horsepower per pound of material was realized.

"As to steam economy, it is highly satisfactory, comparing well with the best turbines, the consumption being thirty-six pounds per horsepower-hour with free exhaust and back pressure of a few pounds, which would mean less than seventeen pounds for a two-stage machine of that size. This economy could still be greatly increased for the turbine was operated under conditions of maximum output and not maximum economy."

Mr. Tesla stated that there was no limit to the capacity for which this turbine could be built and said that the peculiar characteristics of this form of construction would make it possible to attain economy of operation with superheated steam not heretofore realized. When operated as a water turbine it greatly simplified the present methods of regulation and opened up a field of application which was stupendous.