2 Formulae
Clasification Society 2023 - Version 9.38
Statutory Documents - IMO Publications and Documents - Resolutions - Maritime Safety Committee - Resolution MSC.245(83) - Recommendation on a Standard Method for Evaluating Cross-flooding Arrangements - (Adopted on 12 October 2007) - Annex - Recommendation on a Standard Method for Evaluating Cross-flooding Arrangements - 2 Formulae

2 Formulae

  2.1 Time required from commencement of cross-flooding θ 0 to the final equilibrium θf:

  2.2 Time required to bring the ship from any angle of heel θ to the final equilibrium θf :

  2.3 Time required from commencement of cross-flooding θ 0 until any angle of heel θ is achieved:

T = Tf T θ

  2.4 Dimensionless factor of reduction of speed through an equalization device, being a function of bends, valves, etc., in the cross-flooding system:

where F is not to be taken as more than 1.

Values for k can be obtained from appendix 2 or other appropriate sources.

  2.5 Cross-flooding through successive devices of different cross-section:

If the same flow crosses successive flooding devices of cross-section S1, S2, S3 having corresponding friction coefficients k1, k2, k3, then the total k coefficient referred to S1 is:

Σ k = k1 + k2 S1 2/S2 2 + k3 S1 2/ S3 2

  2.6 If different flooding devices are not crossed by the same volume, each k coefficient should be multiplied by the square of the ratio of the volume crossing the device and the volume crossing the reference section (which will be used for the time calculation):

Σ k = k1 + k2 S1 2/S2 2 W2 2 / W1 2 + k3 S1 2 / S3 2 W3 2 / W1 2

  2.7 For cross-flooding through devices in parallel that lead to the same space, equalisation time should be calculated assuming that:

S F = S1 F1 + S2 F2 +

with F = 1/ for each device of cross-section Si


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