Example
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - Resolutions - Assembly - IMO Resolution A.266(VIII) – Recommendation on a Standard Method for Establishing Compliance with the Requirements for Cross-Flooding Arrangements in Passenger Ships – (Adopted on 20 November 1973) - Annex - Recommendation on a Standard Method for Establishing Compliance with the Requirements for Cross-Flooding Arrangements in Passenger Ships - Example

Example

 Cross-flooding pipe, diameter (D) 0.39 m, length (l) 21.0 m cross-section area (S) 0.12 m2.

'k' values for the cross-flooding system:
Inlet 0.45
Pipe friction 1.08
2 Radius bends (α=45°) 0.36
Non-return valve 0.50
Outlet 1.00
  Σk = 3.39
Initial angle of heel = θo = 11.9°
Head before cross-flooding commences = Ho = 5.3 m
Head after complete cross-flooding = hf = 1.5 m

 Time to complete cross-flooding =

 In this case:

W = final volume of water entering the equalizing compartment
= 365 m3
=
= 815 seconds (13.6 minutes)

 The vessel is balanced at 7° using the stability curve and H θ measured to the equilibrium waterplane. W is now the volume added to reduce the heel angle from 7° (or θ) to zero.

 Time from 7° heel to upright =

 Head after partial cross-flooding to 7° heel = Hθ = 3.7 m

  • and W = 160 m3

  • = 400 seconds (6.7 minutes)

  ∴ Time from start of cross-flooding to 7° heel = To - Tθ

  • = 415 seconds (6.9 minutes)

Parent topic: Annex - Recommendation on a Standard Method for Establishing Compliance with the Requirements for Cross-Flooding Arrangements in Passenger Ships
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