Downflooding angle related to intact stability is the angle of heel at which the lower edge of openings in the hull, superstructures or deckhouses that cannot be closed weathertight immerse.
Air inlets to the Engine Room must be always open and the downflooding angle for the intact stability shall be calculated taking into account these openings. Some types of dangerous cargoes require continuous ventilation; in such cases it is necessary check the downflooding angle also for hold ventilation openings.
- Downflooding angle related to damage stability – The minimum heel angle where an external opening without watertight closing appliance is submerged.
Hold ventilation openings/fans are usually protected only by weathertight closures and these are openings to be taken into account for damage stability calculation.
