SELECTING THE POWER OF TRANSVERSE THRUSTERS

A decision on the power output required from the transverse thruster for a new ship depends on the ship type, its area of operation, the owner's requirements, and certain other criteria. The need for increased safety in navigation is one of the most important reasons for installing a thruster of adequate power; the capital and operating costs are amortised within a few years by the savings in tug costs and in waiting for tug assistance. Available data from model and full-scale tests are insufficient for an analytic solution to the problem of deciding on the power; the thruster chosen can be similar to that of an existing similar ship with known good manoeuvring performance, but if the new ship differs appreciably from existing ships either in design or in operational conditions, then model tests may be found useful although their reliability may be uncertain. After discussing these aspects of power selection, the Author reviews some of the literature and its proposals, which range from installing a thruster with a power equal to 10% of the ship's propulsion power, to approximation formulae which take a number of parameters into account. A particularly important parameter, according to the literature, is the ship's lateral area; this, and the influence of the total efficiency of the transverse-thruster installation, together with a lack of uniformity in manufacturers' data on the performance of their thrusters, are discussed. Factors affecting total efficiency of the thruster are also discussed; ship-speed is the most important of these. For merchant ships, static thrust has been found to be an adequate design criterion, and the calculated power must be considered in relation to that of thrusters offered by the manufacturer. A series of six standard thrusters, produced by Poland for the COMECON countries, is listed, with their tunnel diameters and power outputs. A general recommendation is that, where there is room for doubt, the more powerful thruster should be chosen. Order from BSRA as No. 49,285.

  • Corporate Authors:

    VEB Autobahnbaukombinat

    Templinestrasse 19
    Potsdam,   Germany 
  • Authors:
    • Kohn, H
  • Publication Date: 1978-5

Language

  • German

Media Info

  • Features: References;
  • Pagination: p. 232
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00188148
  • Record Type: Publication
  • Source Agency: British Ship Research Association
  • Files: TRIS
  • Created Date: Feb 27 1979 12:00AM