5 Calculation of the A/Amax ratio - (resolution MSC.26(60) and MSC/Circular.574 )
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Statutory Documents - IMO Publications and Documents - Circulars - Maritime Safety Committee - MSC/Circular.649 – International Convention for the Safety of Life at Sea, 1974, as amended – (Adopted on 8 June 1994) - Annex - Interpretations of Provisions of Resolution MSC.26(60) and MSC/Circular.574 - 5 Calculation of the A/Amax ratio - (resolution MSC.26(60) and MSC/Circular.574)

5 Calculation of the A/Amax ratio - (resolution MSC.26(60) and MSC/Circular.574 )

  5.1 Identical assumptions should be made regarding the extent of damage penetration when calculating the `A' values for both the actual and notional ship KG values. This damage penetration extent should be no less than B/5, measured inboard from the ship side. However, contributions to these `A' values may be included for damage cases involving penetration extents in excess of B/5.

  5.2 Where there is longitudinal bulkhead nearer to the ship side than B/5, it should be assumed to be penetrated. In such a case, there may be a further damage case to be considered within the same longitudinal damage zone. Both the 'A' values should be calculated accordingly.

  5.3 Where a ship has been constructed to a two-compartment standard of subdivision, 'A' should be calculated using a notional ship KG appropriate to that for which the 's' values calculated for the two-compartment damage cases are unity. In such a case, it may be assumed that all the 's' values for the one-compartment damage cases are also unity. The corresponding A/Amax ratio is then given by the ratio:

where:
A1 = is that part of the 'A' value calculated for the one-compartment damage cases, using the actual KG;
A2 = is that part of the 'A' value calculated for the two-compartment damage cases, using the actual KG;
Amax 1 = is that part of the 'A' value calculated for the one-compartment damage cases, using the notional KG;
Amax 2 = is that part of the 'A' value calculated for the two-compartment damage cases, using the notional KG;

  5.4 Where a ship has been constructed to a one-compartment standard of subdivision, 'A' should be calculated using a notional ship KG appropriate to that for which all the 's' values calculated for the one-compartment damage cases are unity. For the purposes of future analysis, the A/Amax ratio should be calculated using the formula:


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