The measurement of ship-speed, power, and rpm during a voyage, in the interests of monitoring fuel consumption, will give a somewhat inexact qualitative assessment of an increase in hull roughness. A more accurate, quantitative assessment is, however, not possible, since external influences such as weather and seaway cannot be accurately estimated. To ovecome this difficulty, the Author presents a method that should yield more accurate results without undue expenditure. It is based on the shipboard measurements normally made (speed, power, and rpm), and on the open-water propeller curve and some simplifying assumptions. The relevant propeller-curve is calculated with the aid of geometrical data from the polynomial representation of the Wageningen B series. The method is explained by means of a worked example, and the results and their accuracy are discussed. The article is presented under the headings:--(1) Introduction. (2) Basic Data and Conventional Treatment. (3) Application of the Open-Water Propeller Curves. (4) Calculation of the Appropriate Open-Water Curve. (5) Analysis, with the Open-Water Propeller Curve, of the Values Measured during the Voyage. (6) Example. (7) Checking the Accuracy of the Interpolated Open-Water Curve. Order from BSRA as No. 54,613.

  • Corporate Authors:

    Schroedter (C) and Company

    Stubbenhuk 10
    Hamburg 11,   Germany 
  • Authors:
    • Brehme, H
  • Publication Date: 1980-9


  • German

Media Info

  • Features: References;
  • Pagination: p. 1356
  • Serial:
    • HANSA
    • Volume: 117
    • Issue Number: 18
    • Publisher: Deutsche Bahn AG

Subject/Index Terms

Filing Info

  • Accession Number: 00329917
  • Record Type: Publication
  • Source Agency: British Ship Research Association
  • Files: TRIS
  • Created Date: Mar 12 1981 12:00AM