Weathertight closing appliances

Weathertight closing appliances
D.3.1 Inlet and exhaust openings of ventilation systems are to be provided with easily accessible
closing appliances, which can be closed weathertight against wash of the sea. In ships of less than 100 m
in length, the closing appliances are to be permanently attached. In ships exceeding 100 m in length, they
may be conveniently stowed near the openings to which they belong.
D.3.2 For ventilator posts which exceed 4.5 m in height above the freeboard deck or raised quarterdeck
and above exposed superstructure decks forward of 0.25 L from F.P. and for ventilator posts exceeding
2.3 m in height above exposed superstructure decks abaft 0.25 L from F.P. closing appliances are
required in special cases only.
D.3.3 For the case of fire draught-tight fire dampers are to be fitted.
D.3.4 Weathertight closing appliances for all ventilators are to be of steel or other equivalent materials.
Wood plugs and canvas covers are not acceptable in these positions.
D.3.5 Closing appliances are to be examined and tested for weathertightness by water jet (from a
12.5 mm dia. nozzle and a minimum hydrostatic pressure of 2.0 bar from a distance of 1.5 m).
D.3.6 For special strength requirements for fore deck fittings, see D.2.2.
D.3.7 Rotating type mushroom ventilator heads are unsuitable for application in the areas defined in