SHIPS' ROLL STABILISERS

The Author, of Sperry Ship Stabilizing Systems, explains the fundamentals of ship-rolling dynamics, including the associated response analysis, and describes the principles of operation of tank stabilisers of the passive, passive controlled, and activated types. The treatement is, in general, non-mathematical, and includes some discussion on the merits of these tank stabilising systems. The principles of operation of active fin stabilisers are then explained, and this type of stabiliser is discussed with particular reference to the Sperry Gyrofin, which was introduced in 1956. Control of active fins can be based on the fins' lift or on their angle of attack. The Gyrofin uses the former method, the lift force being measured and used to control the attitude of the fin, and the advantages of this method, and other advantages of the Gyrofin, are discussed, including its use (in merchant ships) of the apparent vertical instead of the true vertical as the stabilisation reference. There is also a general discussion on the cavitation problem with stabilising fins. Operational requirements and economic considerations will determine which type of stabiliser is most appropriate. In the recent past, developments have been mainly concerned with refinements in control equipment and the incorporation of solid state electronics in the computation of control signals. Further developments in control systems are likely, but the fundamental features of the tanks or the fins will probably persist. It is also mentioned that Gyrofin stabilisers are still giving good service on Italian railway ferries after over 20 years' service, and recent surveys have recommended that, after minor refurbishing, their life should be extended for a further ten years.

  • Availability:
  • Corporate Authors:

    National Institute of Shipbuilding and Shipping

    10 Burgemeester & Jacobplein
    Rotterdam,   Netherlands 
  • Authors:
    • Bennett, D A
  • Publication Date: 1980-10

Media Info

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Filing Info

  • Accession Number: 00331574
  • Record Type: Publication
  • Source Agency: British Ship Research Association
  • Files: TRIS
  • Created Date: May 21 1981 12:00AM