Hull Construction Regulations

46 (1) In every ship every lift trunk, and every light-and-air and similar trunk in an accommodation space or service space shall be constructed of “A” Class divisions, provided that a lift trunk within a stairway enclosure shall not be required to be insulated; every door in such a trunk shall be constructed of steel or other incombustible material and shall be as effective as the trunk in resisting fire.

(2) Every lift trunk shall be so fitted as to prevent the passage of smoke and flame from one between decks to another and shall be provided with means of closure that will enable draught and smoke to be controlled.

(3) If a light-and-air or similar trunk communicates with more than one between decks space and smoke and flame may be conducted from one between decks to another, smoke shutters shall be fitted so as to enable each such space to be isolated in the event of fire.

(4) Every other trunk shall be so constructed as not to afford a passage for fire from one between decks or compartment to another.