REDUCING THE FUEL CONSUMPTION AND OPERATING COSTS OF SEAGOING SHIPS BY IMPROVEMENTS IN PROPULSIVE EFFICIENCY

Fuel costs are now much the largest item in the costs of operating a ship. Specific consumption can hardly be reduced further, but hydrodynamic measures to save fuel by reducing the power requirement can be incorporated in the design of a new ship. The Author discusses a number of factors relevant to such measures, including: the large slow-running propeller, block coefficient; L/B ratio; ship length; forebody form; waterplane form; bulbous bows; afterbody form; ratio of forebody fullness to afterbody fullness; and the asymmetrical stern. The asymmetrical stern is discussed more fully than other measures; its development was started in 1965, and models of a variety of asymmetrical stern-forms have been tested at the HSVA. An asymmetrical stern can enable a power saving of 6 to 7% to be made; this saving has been demonstrated in model tests of several ships with block coefficients between 0.75 and 0.83, and may be larger for forms with a lower C sub B. The article includes, for a 170,000-dwt bulk carrier having a C sub B of 0.82 and an asymmetrical stern, a body-plan of the stern, a wake-distribution diagram, and shp/speed curves in which the performance is compared with that of a ship with a conventional stern. The article also gives a brief explanation of the hydrodynamics of the asymmetrical stern and the propeller, and mentions that the extra cost of such a stern would be amortised in not longer than 1-1/2 years in the case of an 11,000-dwt multi-purpose cargo-ship and in six months in the case of a 170,000-dwt bulk carrier. Order from: BSRA as No. 48,290.

  • Corporate Authors:

    Schroedter (C) and Company

    Stubbenhuk 10
    Hamburg 11,   Germany 
  • Publication Date: 1978-1

Language

  • German

Media Info

  • Pagination: 2 p.
  • Serial:
    • HANSA
    • Volume: 115
    • Issue Number: 2
    • Publisher: Deutsche Bahn AG

Subject/Index Terms

Filing Info

  • Accession Number: 00178188
  • Record Type: Publication
  • Source Agency: British Ship Research Association
  • Files: TRIS
  • Created Date: Jul 19 1978 12:00AM