Peak and machinery space bulkheads, shaft tunnels, etc.
31.—(1)  (a)  A ship shall have a forepeak or collision bulkhead, which shall be watertight up to the bulkhead deck. This bulkhead shall be fitted not less than 5% of the length of the ship, and not more than 3.05 metres plus 5% of the length of the ship from the forward perpendicular.
(b)  If the ship has a long forward superstructure, the forepeak bulkhead shall be extended weathertight to the deck next above the bulkhead deck. The extension need not be fitted directly over the bulkhead below, provided it is at least 5% of the length of the ship from the forward perpendicular, and the part of the bulkhead deck which forms the step is made effectively weathertight.
(2)  An afterpeak bulkhead, and bulkheads dividing the machinery space, referred to in regulation 26(h), from the cargo and passenger spaces forward and aft, shall also be fitted and made watertight up to the bulkhead deck. The afterpeak bulkhead may be stepped below the bulkhead deck, where the degree of safety of the ship as regards subdivisions is not thereby diminished.
(3)  In all cases stern tubes shall be enclosed in watertight spaces of moderate volume. The stern gland shall be situated in a watertight shaft tunnel or other watertight space separate from the stern tube compartment and of such volume that, if flooded by leakage through the stern gland, the margin line will not be submerged.
(4)  Fuel oil shall not be carried in the peak tanks.