Service experience with 9 fast, single-screw containerships has shown that a certain amount of cavitation erosion occurs on semi-spade rudders. The extent of the erosion tends to increase during the first 3 to 5 years of service and is attributed to the high service speed of 24 to 25 knots in combination with the oblique flow to the rudder horn and rudder blade and with the disturbed flow around the lower pintle. A series of model tests carried out in a cavitation tunnel has shown that cavitation erosion can be reduced by fitting deflection blades to the sides of the lower pintle. These will deflect the flow and cause it to separate in passing from the rudder horn to the rudder blade. The cavitation erosion in the horizontal gap between the rudder horn and the rudder blade can be reduced by fitting "end plates" to the horn and rudder blade. These minor modifications have no effect on the cavitation erosion due to the oblique flow in the propeller slipstream. To overcome this problem, the use of corrosion-resistant materials has been investigated. Hydrodynamic solutions briefly reviewed include double rudders, contra-rotating propellers and a wake-adapted rudder.

  • Supplemental Notes:
    • Jahrbuch der Schiffbautechnischen Gesellschaft, 76 <1982>, p.471 (25 pp., 3 ref., 4 tab., 3 graphs, 9 diag., 19 phot.)
  • Authors:
    • Kappel, J J
  • Publication Date: 1982


  • German

Subject/Index Terms

  • Subject Areas: Marine Transportation;

Filing Info

  • Accession Number: 00685777
  • Record Type: Publication
  • Source Agency: British Maritime Technology
  • Files: TRIS
  • Created Date: Aug 14 1995 12:00AM