Regulation 17(2) requires that the coamings of machinery
space ventilators situated in exposed positions on the freeboard and
superstructure decks shall be as high above the deck as is reasonable
and practicable.
In general, ventilators necessary to continuously supply
the machinery space and, on demand, immediately supply the emergency
generator room should have coamings which comply with regulation 19(3), without having to fit weathertight
closing appliances.
However, where due to ship size and arrangement this is
not practicable, lesser heights for machinery space and emergency
generator room ventilator coamings may be accepted with the provision
of weathertight closing appliances in accordance with regulation 19(4) in combination with other suitable
arrangements to ensure an uninterrupted, adequate supply of ventilation
to these spaces.