(1) Ventilators in position 1 or 2 to spaces below
freeboard deck or decks of enclosed superstructures shall have coamings
of steel or other equivalent material, substantially constructed and
efficiently connected to the deck. Ventilators in position 1 shall
have coamings of a height of at least 900 mm above the deck; in position
2 the coamings shall be of a height at least 760 mm above the deck.
Where the coaming of any ventilator exceeds 900 mm in height it shall
be specially supported.
(2) Ventilators passing through superstructures
other than enclosed superstructures shall have substantially constructed
coamings of steel or other equivalent material at the freeboard deck.
(3) Ventilators in position 1 the coamings of
which extend to more than 4.5 m above the deck, and in position 2
the coamings of which extend to more than 2.3 m above the deck, need
not be fitted with closing arrangements unless specifically required
by the Administration.
(4) Except as provided in paragraph (3), ventilator
openings shall be provided with weathertight closing appliances of
steel or other equivalent material. In ships of not more than 100
m in length the closing appliances shall be permanently attached;
where not so provided in other ships, they shall be conveniently stowed
near the ventilators to which they are to be fitted.
(5) In exposed locations, the height of coamings
may be increased to the satisfaction of the Administration.