Published Resources Details Journal Article

On the formation of cavities in water by screw propellers at high speeds
The Engineer
vol. 84, 16 July 1897, p. 59

Accession No.507


An abstract of S. W. Barnaby's paper "On the formation of cavities in water by screw propellers at high speed." read at the International Congress of Naval Architects and Marine Engineers in 1897. In an earlier paper S. W. Barnaby and J. I. Thornycroft had described how this phenomenon had affected the performance of H.M.S. Daring (John Isaac Thornycroft and Sydney Walker Barnaby 'Torpedo-boat Destroyers.' Paper No. 2879, Minutes of Proceedings of The Institution of Civil Engineers, vol. 122, part 4, 1894-1895, pp. 51-103). S. W. Barnaby was of the opinion that the speed of vessels was approaching a stage at which propulsion by screw propellers would become less efficient. He concluded that cavitation would continue to cause problems in the future as it was already becoming difficult to obtain the requisite area in screws of destroyers without either resorting to an abnormal width of blade or to a larger diameter or pitch ratio than would be otherwise preferable. The one expedient gave undue surface friction, and the other necessitated a reduction in the rate of revolution, and therefore a heavier engine. The fact that C. W. Parsons the designer of the Turbina had been forced to employ nine screws in order to avoid cavitation was cited as proof of the note of warning that Barnaby and Thornycroft had raised in their 1895 paper written after the trials of the Daring.