2.9 Ventilators:

(1) Ventilators in Position 1 and Position 2 to spaces below the freeboard deck or decks of enclosed superstructures shall be of substantial construction of steel or equivalent material and-

• (a) ventilators in Position 1 shall have coamings of a height of at least 900 millimetres above the deck;

• (b) ventilators in Position 2 shall have coamings of a height of at least 760 millimetres above the deck; and

• (c) where the coaming of any ventilator exceeds 900 millimetres in height it shall be specially supported.

(2) Ventilator openings shall be provided with weathertight closing appliances of steel or equivalent or have equivalent means of preventing ingress of water and the means of closing shall-

• (a) in ships of less than 100 metres in length, be permanently attached to each of the ventilators; and

• (b) in ships of 100 metres or more in length, if not permanently attached to the ventilator the means of closing shall conveniently stowed near the ventilators to which they are to be fitted.

(3) Where due to ship design and arrangements compliance with subsections (1) and (2) is not practicable, lesser heights for ventilator coamings, fitted with weathertight closing appliances, may be permitted by the Administration in combination with other suitable arrangements to ensure an uninterrupted, adequate supply of ventilation to the spaces.

(4) In exposed locations, the height of coamings shall be increased as required to the satisfaction of the Administration.

(5) Subject to the meeting the requirements for fire protection contained in Chapter 6, ventilators-

• (a) in Position 1, the coamings of which extend to more than 4.5 metres above the deck; and

• (b) in Position 2, the coamings of which extend to more than 2.3 metres above the deck,

need not be fitted with closing arrangements unless specifically required by the Administration.