This article, which includes a brief explanation of how the Tip Vortex Free propeller prevents tip vortex formation <see Abs. Nos. 56978, Feb., & 57356, May 1982>, gives some results of in-service trials of two ships fitted with a TVF propeller and nozzle. Full results were being published in Sept. 1983 by AESA, the Spanish shipyard group which developed the device. The two ships are the 34,683-dwt bulk carrier Sokorri and the 270,000-dwt tanker Rio Tinto. The bulk carrier showed a power saving of 20% in ballast, but less than this when fully laden; a "semi-tunnel" was added to the stern, leading to a power saving of 24% in ballast and 14% fully laden. A semi-tunnel fitted to the tanker was ineffective; without the semi- tunnel, power saving is believed to be 15%. Annual fuel savings for a typical large tanker are estimated at up to 1.4 million US dollars. The propeller will be marketed by SATENA <an ASEA subsidiary> and the ASTANO shipyard. The intention is to offer three options: the TVF propeller alone, which could save about 10% power; the propeller and nozzle, giving a power reduction of 15 to 20%; and propeller, nozzle, and <if the hull form is such that performance would benefit> a semi- tunnel, with a power reduction of 15 to 20% or more. Pay-back time is estimated at about 18 months.

  • Supplemental Notes:
    • Motor Ship, 64 <1983>, p. 69 <Sept.> (1 p., 1 phot.)
  • Publication Date: 1983


  • English

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Filing Info

  • Accession Number: 00685755
  • Record Type: Publication
  • Source Agency: British Maritime Technology
  • Files: TRIS
  • Created Date: Aug 14 1995 12:00AM