During the last two decades ships have increased in size to just over 550,000 dwt. However, ports and harbours have not developed at the same rate and under-keel clearances have become progressively less; as service speeds have also increased considerably these developments have produced problems in ship handling in shallow water. The Author develops formulae for estimating the depth of influence for different types of ship, lists the signs indicating that the ship has entered shallow water (e.g. increased wavemaking forward), and discusses the different types of manoeuvring and turning circle trials. One of the biggest problems caused by the increases in size and speed of ships is squat. With full-form vessels, such as VLCCs or OBOs grounding will occur generally at the bow, while for fine-form vessels such as passenger or container ships it will occur at the stern. A formula that will be satisfactory for estimating squat for ships operating in confined channels and open-water conditions, is presented.

  • Supplemental Notes:
    • Marine Design International Supplement (1979).
  • Corporate Authors:

    IPC Industrial Press Limited

    Dorset House, Stamford Street
    London SE1 9LU,   England 
  • Authors:
    • Barrass, C B
  • Publication Date: 1979-3

Media Info

  • Pagination: p. 20
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00315002
  • Record Type: Publication
  • Source Agency: British Ship Research Association
  • Files: TRIS
  • Created Date: Aug 27 1980 12:00AM