.-(1) Petroleum Class A shall not be carried below deck in decked vessels unless there are efficient ventilators in the hold.(2)Half of the ventilators referred to in sub-rule (1) shall be carried down nearly to the bottom of the holds and the other half of such ventilators terminated only a short distance below the deck, the short ventilators shall be labelled "Outlet or to Leeward" and the long ventilators shall be labelled "Inlet or to Windward", such ventilators shall have large cowl heads, the openings being covered with double copper or non-corroding metal gauze not less than 11 meshes per linear centimetre.
