Modern ships are usually maintained on course by an electronic auto-pilot, which establishes a course-regulating loop obtained by using the rudder to correct disturbances from wind and sea in order to keep an acceptably low course error. However, the rudder movements required for making the corrections introduce a braking effect on the ship, causing loss of speed and/or unnecessary fuel consumption. The effect, which increases with ship speed and rudder angle, can be intensified by faults liable to occur in most course-regulating loops. A new type of steering gear, developed jointly by DISA Marine and EMRI ApS, incorporates an improved servo system designed to reduce power loss. This has been achieved by minimising the servo error without increasing the steering power. Two essentials of the new system are its use of the analog steering principle, employing a variable-delivery pump whose oil flow is controlled by a pressure signal, and an electronic feed-back unit and serve unit supplied by the factory as a finished and tested combined unit. The system and its mode of operation are described together with the results of trials on a ship at sea which was steered with a course error of 1/6 deg. using 1/2 to 1 deg. rubber angle. Order from BSRA as No. 47,047.

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  • Corporate Authors:

    Institute of Marine Engineers

    Memorial Building, 76 Mark Lane
    London EC3R 7JN,   England 
  • Publication Date: 1977-4

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Filing Info

  • Accession Number: 00170171
  • Record Type: Publication
  • Source Agency: British Ship Research Association
  • Files: TRIS
  • Created Date: Mar 7 1978 12:00AM