What informations are available in Trim and stability booklet?

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Written by Amit Sharma

 Information to be included in the trim and stability booklet

General

A trim and stability booklet is a stability manual, to be approved by the classification  Society, which is to contain information to enable the Master to operate the ship in compliance with the applicable requirements contained in the Rules.
The format of the stability booklet and the information included vary depending on the ship type and operation.

 List of information

The following information is to be included in the trim and stability booklet:

  • a general description of the ship, including:
    1. the ship’s name and the Society classification number
    2. the ship type and service notation
    3. the class notations
    4. the yard, the hull number and the year of delivery
    5. the Flag, the port of registry, the international call sign and the IMO number
    6. the moulded dimensions
    7. the draught corresponding to the assigned summer load line, the draught corresponding to the assigned summer timber load line and the draught corresponding to the tropical load line, if applicable
    8. the displacement corresponding to the above- mentioned draughts
  • instructions on the use of the booklet
  • general arrangement and capacity plans indicating the assigned use of compartments and spaces (cargo, passenger, stores, accommodation, etc.)
  • a sketch indicating the position of the draught marks referred to the ship’s perpendiculars
  • hydrostatic curves or tables corresponding to the design trim, and, if significant trim angles are foreseen during the normal operation of the ship, curves or tables corresponding to such range of trim are to be introduced. A reference relevant to the sea density, in t/m3, is to be included as well as the draught measure (from keel or underkeel).
  • cross curves (or tables) of stability calculated on a free trimming basis, for the ranges of displacement and trim anticipated in normal operating conditions, with indication of the volumes which have been considered in the computation of these curves
  • tank sounding tables or curves showing capacities, centres of gravity, and free surface data for each tank
  • lightship data from the inclining test, including lightship displacement, centre of gravity co-ordinates, place and date of the inclining test, as well as the Society approval details specified in the inclining test report. It is suggested that a copy of the approved test report be included.

Where the above-mentioned information is derived from a sister ship, the reference to this sister ship is to be indicated, and a copy of the approved inclining test report relevant to this sister ship is to be included.

  • standard loading conditions as indicated and examples for developing other acceptable loading conditions using the information contained in the booklet
  • intact stability results (total displacement and its centre of gravity co-ordinates, draughts at perpendiculars, GM, GM corrected for free surfaces effect, GZ values and curve, criteria as indicated  as well as possible additional criteria specified in Part E when applicable, reporting a comparison between the actual and the required values) are to be available for each of the above-mentioned operating conditions. The method and assumptions to be followed in the stability curve calculation are specified.
  • information on loading restrictions (maximum allowable load on double bottom, maximum specific gravity allowed in liquid cargo tanks, maximum filling level or percentage in liquid cargo tanks, maximum KG or minimum GM curve or table which can be used to determine compliance with the applicable intact and damage stability criteria) when applicable.
  • information about openings (location, tightness, means of closure), pipes or other progressive flooding sources.
  • information concerning the use of any special cross-flooding fittings with descriptions of damage conditions which may require cross-flooding, when applicable.
  • any other guidance deemed appropriate for the operation of the ship.
  • a table of contents and index for each booklet.

 

About the author

Amit Sharma

Graduated from M.E.R.I. Mumbai (Mumbai University), After a brief sailing founded this website with the idea to bring the maritime education online which must be free and available for all at all times and to find basic solutions that are of extreme importance to a seafarer by our innovative ideas.

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