This article is concerned mainly with the results of tests, made by the Ship Research Institute of the Technical University of Gdansk, of the "Doermile" opening bulb. This is a form of bulbous bow that normally serves the usual function of reducing hydrodynamic resistance, but can be opened up when required into braking shields which increase resistance and so reduce the stopping distance of the ship. It also improves manoeuvrability and ability to maintain course while braking is in operation. Three ways in which the bulb can be opened up are described. In the most practical (type C), two side flaps are hinged outwards on vertical pivots to face forward, leaving a rigid vertical centrepiece to the bulb. Model tests on all three types were made, and the results for type C were supplemented by full-scale tests. It is concluded that the stopping time and distance of a turbine tanker could be reduced by about 40% in ballast condition and by 25-30% when fully loaded from a speed of 16 knots.

  • Availability:
  • Corporate Authors:

    Royal Institution of Naval Architects

    10 Upper Belgrave Street
    ,   United States 
  • Publication Date: 1976-9

Media Info

  • Features: References;
  • Pagination: 2 p.
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00159915
  • Record Type: Publication
  • Source Agency: British Ship Research Association
  • Files: TRIS
  • Created Date: Sep 20 1977 12:00AM