THE EFFECT OF LARGE C.P. PROPELLERS ON STERN TUBE BEARING WEAR

The article shows the value of controllable pitch (C.P.) propellers, and mentions recent bearing designs. Ships with fixed pitch propellers have had excessive bearing wear more often than those with C.P. propellers. Stopping and reversing a shaft breaks up the oil film, resulting in a greater load on the stern tube bearing. A C.P. shaft always rotates in the same direction, eliminating risk of dry friction. In one recent test 25 to 30 rev/min was needed to insure a good film. With a C.P. propeller the vessel's speed could be cut down to zero. Less shaft starts are made with the C.P. propeller. Recent bearing designs include a horizontally split stern tube bearing, an assembly that can be moved forward in a single unit, and the spherical roller bearing, which has given good results on small ships. Advantages of these types of bearings are listed and explained.

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  • Supplemental Notes:
    • Article based on report by Ralph Norrby.
  • Corporate Authors:

    Engineering, Chemical and Marine Press, Limited

    33-39 Bowling Green Lane
    London EC1P 1AH,   England 

    Engineering, Chemical and Marine Press, Limited

    33-39 Bowling Green Lane
    London EC1P 1AH,   England 
  • Publication Date: 1972-7

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Filing Info

  • Accession Number: 00037093
  • Record Type: Publication
  • Source Agency: United States Merchant Marine Academy
  • Files: TRIS
  • Created Date: Nov 10 1974 12:00AM